# How to Prepare a New-Home Indoor Air Quality Brief Before Schematic Design Source: https://brictale.com/build/design/prepare-new-home-indoor-air-quality-brief-before-schematic-design Published: 2026-10-05 Audience: Homeowner Published by Brictale, a consumer home-intelligence publication. https://brictale.com ## Short answer Before schematic design, create a one-page decision brief plus a room-by-room handoff matrix. Record occupants and sensitivities, site pollutants, moisture and radon context, combustion and garage sources, desired controls, responsible people, drawing locations, verification evidence and unresolved risks. Treat EPA and DOE guidance as design inputs—not universal local code—and have the architect, HVAC designer, builder, rater and actual authority having jurisdiction resolve project-specific requirements. --- # How to Prepare a New-Home Indoor Air Quality Brief Before Schematic Design Before schematic design, approve a short IAQ brief that names the people, site conditions, rooms, pollutant sources, desired controls, drawing locations, verification evidence and unresolved decisions. Start with the household and site, then have the architect or designer, HVAC designer, builder, rater and the actual local authority having jurisdiction translate the brief into a coordinated design. EPA and DOE guidance are valuable inputs, but neither is a universal U.S. building code or a remote diagnosis. This guide is for a new, single-family home in the United States before schematic design. The homeowner owns the decision to approve the brief; the qualified design and construction team owns technical design, code compliance, installation and verification. The goal is not to promise perfect air. It is to prevent an important concern from disappearing between a conversation, a floor plan, an HVAC proposal, a specification, construction and occupancy. ### Approve the brief only when every IAQ concern has an owner and a next decision Approve the brief for schematic design when each material concern is expressed as a decision with an input, an accountable person, a place in the design record, a verification gate and a next handoff. A list of preferred products or a promise to “build healthy” is not enough. The brief should show what the household is trying to control, where the source or exposure path is, what the project team will do, what remains unknown and who must resolve it before the next approval. EPA describes Indoor AirPlus Version 2 as a framework with design, construction and verification requirements, and publishes separate verification, builder-responsibility and checklist documents. That makes it a useful organizing reference for a homeowner brief, but it remains a program framework rather than a universal permit requirement. Use the current [EPA Indoor AirPlus program documents](https://www.epa.gov/indoorairplus/indoor-airplus-program-documents) as a source of questions and possible specifications, then ask the project’s actual authority having jurisdiction (AHJ)—for example, the named city, county or state permitting authority—to confirm adopted codes and amendments for this site. Do not write “the code requires” unless that authority or the project’s code professional has confirmed the exact jurisdiction, edition and provision. ### The decision this brief must support At the end of the pre-schematic conversation, the homeowner should be able to answer: > “Do we have enough known information to let the designer draw a home whose rooms, enclosure, HVAC, ventilation, exhaust, materials, garage separation, moisture control, radon strategy and construction protections reflect our actual priorities—and a named person can close every open item?” If the answer is no, the next decision is not “pick a filter.” It is to identify the missing input and assign the shortest safe path to obtaining it. That may be a site visit, a radon-potential check, a local-health-department conversation, an HVAC design question, a materials submittal requirement or a decision about whether a combustion appliance belongs in the home at all. ### Compact originality brief Existing answers from EPA, DOE, certification programs and building-science research explain individual protections: moisture control, radon-resistant construction, ventilation, filtration, source control, duct protection and low-emission materials. They are useful, but they are usually organized by program or hazard rather than by the homeowner’s schematic-design meeting. The missing decision is how a homeowner turns household needs and site observations into a scoped design handoff before room shapes and mechanical routes harden. The reader needs to know what to collect, what not to infer, who answers the technical question, where the answer belongs, what can be checked before concealment and what unresolved risk blocks approval. The original contribution is **The IAQ design-brief worksheet and handoff matrix**. It is a reusable table in this article. **Method: record one concern per row, trace it from source and affected room to control, responsible person, drawing or specification location, verification gate and next decision, then test the brief with an illustrative source-to-control calculation and sensitivity check.** It is a planning synthesis, not field research. **Limitations: this is a planning and handoff instrument, not a code determination, medical assessment, HVAC sizing report, radon result, laboratory test, commissioning certificate or substitute for the project architect, HVAC designer, builder, rater, licensed trades or authority having jurisdiction.** Use this worksheet with Brictale’s broader [design-planning guide](/build/design) when you need to place IAQ decisions in the home’s larger design sequence. You can check the contribution by asking five questions for every row: Is the concern observable or documented? Is the proposed control matched to the source? Does one person accept responsibility? Is the evidence obtainable at the stated gate? Does the next decision change if the item remains open? If any answer is no, the row is not ready for schematic design. ### What belongs in the first page Keep the first page short enough that the design team will use it. Put detailed source notes and product research behind it. Include: 1. Project location: street or parcel identifier, city or town, county if applicable, state, climate context known to the team, and the named permitting AHJ. 2. Stage and decision owner: “pre-schematic design,” homeowner decision owner, anticipated designer or architect, anticipated HVAC designer, builder status, rater or verifier status, and the date of the next meeting. 3. Household: expected occupants at move-in, likely future occupants, pets, smoking or vaping policy, cooking patterns, cleaning products, hobbies, workshop activities, home office or exercise needs, and any sensitivity the household wants the team to consider. 4. Site and neighborhood: nearby roads, agriculture, industry, wildfire smoke history or concern, flood or drainage observations, standing water, fill, slope, existing structures, attached or detached garage concept, and any available environmental or real-estate records. 5. Decisions requested: ventilation approach, combustion strategy, filtration goal, moisture and radon investigation, source-control priorities, room adjacencies, material requirements, construction protection, verification and handover records. Do not put medical diagnoses, confidential medical records or a claim that a person is “safe” in the brief. Record a household preference such as “avoid fragrance and minimize dust exposure” or “occupant has a clinician-documented respiratory condition; family wants HVAC and construction decisions reviewed with the clinician’s advice.” The designer can act on the preference without pretending to diagnose or guarantee health outcomes. ![Flow from household and site inputs to an IAQ brief, design handoff and approval decision](https://brictale.com/images/home/build/design/prepare-new-home-indoor-air-quality-brief-before-schematic-design/iaq-brief-handoff-map.webp) ## Collect site and household inputs before drawing rooms Collect inputs in five groups before the designer fixes the schematic layout: occupants and activities, outdoor sources, moisture and ground conditions, combustion and garage sources, and the existing information needed to verify each risk. Record facts, observations, documents and unknowns separately so an assumption is never mistaken for a test result. EPA explains that indoor pollution sources are a primary cause of IAQ problems and that inadequate ventilation can increase indoor pollutant levels by failing to dilute or remove contaminants; it also identifies temperature and humidity as factors that can affect some concentrations. That is why the brief begins with sources and activities rather than with equipment. See [EPA’s home IAQ protection guidance](https://www.epa.gov/indoor-air-quality-iaq/protect-indoor-air-quality-your-home) for that source-control and ventilation framing. ### Group 1: occupants, routines and sensitivities Ask the household to describe a normal week, not an idealized brochure life. The useful detail is often a verb: cook, sleep, shower, garden, paint, store, exercise, work, host, clean, dry laundry, practice music or enter from a garage. Each activity can change the source, location, timing or control required. Record these inputs: - Number of occupants at move-in and the likely maximum regular occupancy, with age ranges rather than names. - Sleeping rooms and who uses them, including whether a child, older adult or sensitive occupant needs a quieter or cleaner-air refuge. - Pets, litter, food storage, aquariums and any animal-care activity. - Cooking style: frequent searing, gas cooking if proposed, baking, frying, wok cooking, open-flame cooking, or mostly reheating. - Bathing frequency, preferred shower duration, indoor drying of clothing, and whether a bathroom may be used at night. - Smoking, vaping, candles, incense, fireplaces, wood stoves, hobby chemicals, soldering, 3-D printing, woodworking, arts materials or indoor vehicle work. The preferred answer for many high-emission activities is relocation or exclusion, not a larger fan. - Fragrance, cleaning and pest-control preferences, including whether the household expects to use products that need source-specific storage or ventilation. - Sleep, noise and draft tolerance. A system that is theoretically effective but switched off because it is noisy is not a dependable control. - Whether a room may need to operate as a temporary cleaner-air space during an outdoor smoke event. EPA notes that wildfire smoke can enter homes and that extra steps may be needed in extreme events; see [EPA’s Indoor AirPlus wildfire guidance](https://www.epa.gov/indoorairplus/indoor-airplus-and-wildfires). The homeowner can collect these preferences. Do not translate them into a medical threshold or promise a health result. If a clinician has given the family advice, bring the advice to the design conversation while leaving diagnosis and treatment with the clinician. ### Group 2: outdoor sources and site context Walk or review the parcel at different times if safely possible. The homeowner’s job is to observe and document; the qualified team’s job is to interpret. Note the location and likely timing of: - Busy roads, truck routes, rail lines, airports, idling zones or nearby parking areas. - Agricultural fields, animal operations, fertilizer or pesticide use, wood smoke, industrial activity or commercial exhaust. - Wildfire smoke concern, local wind exposure, smoke seasons and whether the household wants a filtration or refuge strategy. Do not infer that a tight envelope eliminates smoke; EPA expressly says it may not completely eliminate entry. - Existing septic, fuel, oil, chemical or waste storage, abandoned structures, burn piles or evidence of dumping. Escalate uncertain contamination questions to the appropriate environmental professional or local authority. - Surface water, drainage paths, steep slopes, low areas, wet soil, erosion, existing wells, cisterns, ponds and locations where groundwater or stormwater may affect the foundation. - Radon context. Record the county or state information the team obtains from the relevant public-health or environmental authority, but do not turn a regional map into a property measurement. A radon professional can advise on testing, resistant construction and follow-up. Use photos, a simple site sketch, parcel documents, survey information and a date for each observation. Do not trespass, enter an unsafe structure, sample unknown material, disturb suspected contamination or enter a crawlspace, excavation or confined space to obtain an observation. Those tasks belong to qualified professionals using the required controls. ### Group 3: moisture and enclosure inputs Ask the designer and builder to treat moisture as a system problem with multiple paths. DOE Building Science Education identifies bulk water, capillary movement, air-carried moisture and vapor dispersion as distinct transport means, and explains that the appropriate control depends on climate, insulation and construction type. The source is [DOE’s introduction to moisture flow in building enclosures](https://bsesc.energy.gov/energy-basics/building-enclosure-building-science-intro-moisture-flow). The pre-schematic brief should therefore record: - Foundation type under consideration: basement, crawlspace or slab, plus whether the decision is still open. - Site slope and the intended direction of roof and surface-water drainage. - Whether the project is in a humid, mixed, cold, hot-dry or hot-humid context, as confirmed by the design team for the actual location. - Floodplain, high-water, groundwater or drainage information that may change the foundation and enclosure strategy. - Desired locations for bathrooms, laundry, kitchen, mechanical rooms and other moisture-producing spaces. - Whether ducts, air handlers or other equipment may be in attics, garages, crawlspaces or other locations where temperature and moisture control are different. - Materials or assemblies the owner is considering that require climate-specific vapor or drying analysis. - Who will provide any hygrothermal analysis, water-management detail, drainage design or enclosure review, and when. The homeowner should not select a vapor retarder, insulation assembly or foundation detail from a national checklist without the project’s climate and assembly review. A detail that controls one transport path can worsen another if the full enclosure is not understood. ### Group 4: combustion, garage and attached-space inputs Decide early whether the home will have gas, propane, oil, wood or other combustion equipment; a fireplace; an attached garage; a workshop; or storage for fuels, paints and chemicals. The question is not merely “which appliance is most efficient?” It is “what sources might enter occupied air, what separation and exhaust are needed, and who verifies that the source cannot spill into the home?” EPA’s description of Indoor AirPlus includes properly vented heating equipment, carbon monoxide alarms in sleeping areas and measures to stop garage pollutants from entering the house. Review the exact program context in [EPA’s features and benefits page](https://www.epa.gov/indoorairplus/benefits-and-features-indoor-airplus-homes), then have the project team establish the actual design and jurisdictional requirements. Record: - Appliance type, fuel and location under consideration. - Combustion air and venting questions assigned to the HVAC or mechanical designer. - Garage location, door arrangement, mudroom or air-lock concept, storage and vehicle idling expectations. - Whether a workshop, generator, mower, fuel can, battery charging area or chemical storage could share the garage or another attached space. - Exhaust devices that may affect pressure: range hood, bath fans, dryer, central vacuum, dust collection and any intermittent or continuous exhaust. - Alarm locations and power or communication questions assigned to the qualified electrician and local code professional. Never test combustion safety by disconnecting vents, operating appliances in unusual configurations, bypassing alarms or entering a flue or confined mechanical space. The homeowner can state the desired risk boundary; qualified professionals must design, test and adjust the system. ### The input ledger: facts versus assumptions Use a four-column ledger before the first schematic meeting. Every row below is an **illustrative template row**, not a record collected for a real household or site. Replace each value with a dated project record—such as a completed owner questionnaire, dated site walk, survey, public source check or qualified report—before relying on it in design. If the project has no record yet, write “unknown” or “to verify” instead of carrying the example forward. | Input | Status | Evidence or source | Decision affected | |---|---|---|---| | Illustrative template row — two adults and one child expected at move-in | Household statement | Dated owner questionnaire | Bedroom count, occupancy assumptions and ventilation discussion | | Illustrative template row — busy county road about 500 feet west | Preliminary observation | Dated site walk and survey | Outdoor-air intake location and envelope/source-control review | | Illustrative template row — basement still under consideration | Open design choice | Site, budget and geotechnical questions | Foundation moisture strategy, radon path and mechanical location | | Illustrative template row — cooking includes frequent high-heat searing | Household statement | Dated owner questionnaire or project worksheet | Range hood capture, make-up-air and kitchen layout discussion | | Illustrative template row — county radon potential not yet reviewed | Unknown | Assigned public-health or environmental source check | Radon-resistant features and possible testing or mitigation path | | Illustrative template row — attached garage desired | Program decision | Dated owner brief | Separation, door, pressure and storage decisions | The status matters. “Known,” “reported,” “observed,” “documented,” “to verify” and “unknown” are not interchangeable. A designer can use a preliminary observation to ask a question; a permit submission may need a different document; a rater may need a field record; a homeowner should never be told that a preliminary observation proves performance. ## Convert concerns into room-by-room requirements Convert each source or sensitivity into a room-level requirement with a control, a responsible person and a verification point. A room is not only four walls: it is a source location, an air path, a pressure relationship, a maintenance task, an access requirement and a handoff between trades. The worksheet below is the core of the brief. Every row is an **illustrative template row**, not an interview result, measurement or site observation. Copy it into the project’s decision log, replace the example inputs with dated project records, and add rows; do not delete an open row merely because it makes the design inconvenient. A dated record can be an owner questionnaire, site walk, survey, public source check, product record or qualified professional report. Do not treat an undated example as household or site data. | Concern or source | Input and unit | Affected room or path | Desired control | Responsible person | Where it appears | Verification evidence | Unresolved risk / next decision | |---|---|---|---|---|---|---|---| | Illustrative template row — wildfire smoke | Illustrative template — seasonal concern; no indoor measurement yet | Whole home; selected refuge room | Envelope review, filter strategy, outdoor-air operating mode, portable-cleaner option | Architect, HVAC designer, homeowner | Envelope notes, HVAC schedule, operating manual | Air-sealing or rater record if in scope; filter and control submittal; startup instructions | Confirm whether refuge room and backup power are priorities | | Illustrative template row — high-heat cooking | Illustrative template — frequent searing; minutes per cooking event to be confirmed | Kitchen and adjacent living area | Capture at source, discharge route, make-up-air and pressure review | Architect and HVAC designer | Kitchen plan, equipment schedule, mechanical notes | Equipment submittal, installed exhaust path, functional test | Resolve hood type before kitchen layout freezes | | Illustrative template row — shower moisture | Illustrative template — two daily showers; room and exhaust route | Bathrooms and adjacent ceiling/wall assemblies | Local exhaust, run-time control, drainage and enclosure detailing | Architect, HVAC designer, builder | Reflected ceiling plan, mechanical plan, enclosure details | Fan model and route, controls, air-sealing or water-management inspection | Confirm noise/access tradeoff and maintenance access | | Illustrative template row — garage exhaust | Illustrative template — attached garage; vehicle idling prohibited or permitted | Garage, connecting door, mudroom | Separation, sealed penetrations, door and pressure strategy | Architect, builder, HVAC designer | Floor plan, wall/door schedule, details, specifications | Door/penetration inspection, blower or pressure test if specified | Decide whether workshop/storage increases source risk | | Illustrative template row — radon context | Illustrative template — county/site information; property result unknown | Foundation and occupied rooms | Resistant-construction path or professional testing/mitigation decision | Architect, builder, radon professional, AHJ as applicable | Foundation plan, details, specs and owner records | Photo/location record, test report or professional documentation | Resolve foundation type and local program or jurisdiction question | | Illustrative template row — fragrance sensitivity | Illustrative template — household preference; no medical claim | Bedrooms, living areas, storage | Material and cleaning preferences, source storage, ventilation and flush-out plan | Homeowner, architect, builder | Finish schedule, owner manual, construction plan | Product records and turnover instructions | Decide which products require approval before purchase | ### How to fill one row without overpromising Start with the source, not the product. “MERV 13 filter” is not a complete row. The source could be wildfire particulate, pollen, construction dust or ordinary recirculated dust; the affected rooms, fan runtime, filter area, pressure drop, maintenance burden and outdoor-air strategy may differ. Write the input with a unit or a status: “one attached garage,” “three bedrooms,” “two showers per day,” “outdoor smoke concern, seasonal,” “no measured radon result,” “anticipated 90 cubic feet per minute (cfm) of continuous outdoor air—illustrative planning input only.” Units force the team to identify what is actually known. If the input is qualitative, label it qualitative. Name the person who can answer the question, not merely the trade most likely to touch the item. The architect may own coordination, the HVAC designer may own airflow and pressure calculations, the builder may own protection during construction, the rater may own a program verification record, the homeowner may own an operating preference, and the AHJ may control permit acceptance. One row can have several contributors, but one accountable owner should be visible. ### Room-by-room prompts For each room, ask the same seven prompts: 1. What enters the room from outside, another room, an attic, a garage, a crawlspace or a mechanical space? 2. What is generated in the room—moisture, particles, odors, combustion products, chemicals, pests or heat? 3. What control acts at the source before dilution or filtration is needed? 4. What air movement is intentional, and what air movement is leakage or an unintended pressure path? 5. Who needs access to clean, replace, inspect, reset or repair the control? 6. What evidence exists before concealment, at startup and at handover? 7. What decision remains blocked if this row is unanswered? Apply the prompts to at least these spaces: - **Bedrooms:** sleeping occupant, quiet, filter or clean-air refuge needs, door position, supply/return strategy, alarm placement and whether a portable cleaner would be usable without blocking egress or creating noise that defeats use. - **Kitchen:** cooking source, hood capture and discharge, make-up-air question, neighboring room relationship, filter or grease maintenance, pressure interaction with combustion equipment and the actual local requirements confirmed by the project team. - **Bathrooms and laundry:** moisture production, fan location and route, controls, make-up air, drying of clothes, access and water-management details. - **Living and dining rooms:** occupancy peaks, fireplace or candles, outdoor-air intake context, return-air location, smoke refuge use and furniture that could block grilles. - **Mechanical room:** equipment combustion or electrical safety, service clearance, condensate, filter access, noise, drainage, outside-air connections, documentation and who can safely service it. - **Garage and mudroom:** vehicle and chemical sources, door seals, penetrations, storage, pressure and the route by which people enter the home. Do not treat a mudroom as a guaranteed airlock until the design team has defined what it means. - **Basement, crawlspace or slab edge:** ground moisture, radon path, drainage, access, pest entry, ducts, air-handler location and whether the selected foundation changes the source-control plan. An empty row is a decision signal. If the household cannot tell whether an attached garage is essential, the designer cannot responsibly finish the entry and mechanical adjacency. If the team cannot say who checks the filter access, the system may be maintainable only on paper. ![Room-by-room matrix linking IAQ sources, air paths, controls, access and verification](https://brictale.com/images/home/build/design/prepare-new-home-indoor-air-quality-brief-before-schematic-design/room-source-control-matrix.webp) ## Choose controls as a coordinated system, not a shopping list Choose controls in a sequence: eliminate or relocate the source, isolate the source, manage moisture and air paths, ventilate intentionally, filter or clean air when appropriate, then document operation and maintenance. Ventilation, air sealing, filtration, exhaust and moisture control interact; a strong choice in one category can create a problem in another if pressure, airflow, access and climate are ignored. DOE’s Efficient New Homes training describes the high-performance home as a system combining an air-sealed and insulated enclosure, water management, comfort and IAQ protections, with important requirements verified through rater checklists. That systems framing is useful even when the homeowner is not pursuing the DOE program. Read the relevant program context in the [DOE Efficient New Homes training transcript](https://www.energy.gov/cmei/buildings/doe-efficient-new-homes-single-family-version-2-rev-3-web-transcript), including its warnings that program requirements vary by building type, location and permit date. ### 1. Source control comes before dilution Source control is the first question because a fan or filter treats air after a contaminant has entered it. In the brief, ask whether the source can be omitted, moved outdoors, sealed, stored separately, enclosed, captured at the point of generation or scheduled away from occupancy. Examples: - Prohibit smoking and vaping indoors rather than designing around it. - Move paint, fuel and solvent storage out of occupied space and ask the builder or local authority about compliant storage. - Select an electric cooking strategy if it better matches the household’s combustion and pressure preferences; do not assume that fuel choice alone settles exhaust design. - Put dusty hobbies in a separate, appropriately designed outbuilding or work area rather than assuming the central HVAC filter will handle them. - Keep construction dust out of installed ducts instead of planning to clean a contaminated system later. - Resolve bulk-water drainage, roof runoff and foundation water management before treating musty air as a ventilation problem. The homeowner can set the preference. The architect, HVAC designer, builder and qualified trades must determine the buildable and code-compliant implementation. ### 2. Moisture control needs a path and a climate Write down where water could come from, how it moves, where it could condense and how it will dry. DOE identifies four transport paths—bulk, capillary, air-carried and vapor dispersion—so “waterproof” or “vapor barrier” is too vague to be a useful design requirement. Ask the designer to identify the water-control layer, drainage path, air-control layer and vapor-control approach for the actual climate and assembly. The brief should call for evidence, not just a detail name: - Site and roof drainage plan or equivalent design record. - Foundation and below-grade water-management details. - Penetration, sill, window and door water-management details. - Air-sealing continuity review where the enclosure and ducts meet. - Condensation risk review where supply ducts, cold surfaces or humid air interact. - Humidity-control operating guidance for the completed home. Do not infer that a dehumidifier cures a leaking foundation, that a vapor retarder cures bulk water, or that tighter construction makes moisture irrelevant. A mechanical system can remove some moisture under some conditions; it cannot replace source control, drainage or an enclosure designed for its climate. ### 3. Ventilate intentionally, with an exception plan The brief should state what the ventilation system is intended to do, when it operates, how it is controlled, where outdoor air enters, where stale air leaves, how the system is maintained and what happens during smoke or other outdoor-pollution events. It should not simply say “add fresh air.” Ask the HVAC designer to compare the candidate approach—balanced, supply, exhaust, energy-recovery or another qualified design—against the actual enclosure, climate, occupancy, noise, maintenance and pressure conditions. The homeowner does not need to choose a machine before this comparison exists. Lawrence Berkeley National Laboratory’s review of 38 studies describes smart ventilation as a way to ventilate more when it provides an energy or IAQ advantage and less when it provides a disadvantage. The review found savings in some cases but also energy overconsumption in some cases, which is a reason to ask for the control logic and failure behavior rather than assuming “smart” means better. See the [LBNL review of smart ventilation](https://bies.lbl.gov/publications/smart-ventilation-energy-and-indoor). Create two operating modes in the brief: - **Normal mode:** the system’s intended operating schedule, control settings, outdoor-air path, filter arrangement, maintenance interval and homeowner instructions. - **Exception mode:** a temporary response to wildfire smoke or another outdoor event, including who issues the decision, whether outdoor-air ventilation is reduced or paused, how indoor pollutants are controlled while it is paused, how long the exception can last, and how normal ventilation is resumed. EPA’s wildfire guidance says homeowners may temporarily turn off mechanical ventilation during a smoke event and resume it after the event, while also noting that extra steps may be needed in extreme events. Treat this as event guidance, not a universal operating rule. The project team must document the actual system’s safe operating instructions and the local emergency authority’s directions. The homeowner should not improvise by blocking intakes, disabling safety controls or creating combustion hazards. ### 4. Filtration is a design and maintenance decision Set a filtration goal, then have the HVAC designer confirm that the blower, filter area, filter depth, cabinet seal, duct size, return path and maintenance plan can support it. EPA’s wildfire guidance says Indoor AirPlus requires at least MERV 8 in central forced-air HVAC systems and highly recommends MERV 13 for added protection; it also notes that ductless and hydronic systems may need a portable air cleaner when a high-efficiency HVAC filter is unavailable. See [EPA’s wildfire filtration guidance](https://www.epa.gov/indoorairplus/indoor-airplus-and-wildfires). Do not convert the MERV statement into “MERV 13 is always required.” It is an EPA recommendation in the cited wildfire guidance, and filter compatibility remains specific to the system. EPA’s [filtration technical bulletin](https://www.epa.gov/sites/production/files/2020-06/documents/2019.11_tech_bulletin_filtration.pdf) explains that higher-MERV filters can restrict airflow, so the filter box and duct system need to be designed for the pressure limit. It also recommends a sealed, accessible filter location and attention to replacement or cleaning when dirty. Include these filter questions in the brief: - What contaminant is the target: particles, construction debris, pollen, smoke or something else? - Is the filter in recirculated air, outdoor-air intake air or both? - What is the selected filter’s actual nominal size, depth and replacement access? - What pressure-drop information will the HVAC designer use? - What happens if the filter is heavily loaded during a smoke event? - Can a homeowner reach and replace it without a ladder, moving equipment or entering a hazardous space? - Is there a portable-cleaner location with power, clearance, noise tolerance and a maintenance path? - What evidence will be handed over: model, size, rating, location, replacement guidance and operating limitations? A filter is not a substitute for a source-control decision, a ventilation design, a moisture fix or a combustion-safety evaluation. ### Illustrative source-to-control example with sensitivity The following is a **modeled illustrative example**, not a recommendation or a measured result. It shows how the worksheet makes assumptions visible before an HVAC designer sizes anything. Suppose the homeowner says: “We expect two adults and one child, want a tighter home because of seasonal smoke, and want a selected room to be usable as a temporary cleaner-air room. The designer is considering an illustrative 90 cfm continuous outdoor-air input for discussion.” Assume a notional conditioned volume of 24,000 cubic feet. The rough planning conversion is: `air changes per hour = outdoor-air flow (cfm) × 60 minutes per hour ÷ conditioned volume (cubic feet)` `90 cfm × 60 ÷ 24,000 ft³ = 0.225 air changes per hour` That number is only a transparent way to discuss the input. It is not a code rate, a final design rate, a guarantee of pollutant removal or permission to size the system without the qualified designer. The HVAC designer must determine the actual required and feasible airflow using the project’s location, adopted requirements, enclosure, equipment, pressure, distribution, controls, sound and commissioning plan. Sensitivity makes the decision more honest: | Illustrative outdoor-air input | Notional volume | Arithmetic result | What changes in the brief | |---:|---:|---:|---| | 60 cfm | 24,000 ft³ | 60 × 60 ÷ 24,000 = 0.15 ACH | Lower airflow may change dilution, sound, energy and exception-mode questions; designer must evaluate | | 90 cfm | 24,000 ft³ | 90 × 60 ÷ 24,000 = 0.225 ACH | Baseline discussion input only; confirm distribution, controls and pressure | | 120 cfm | 24,000 ft³ | 120 × 60 ÷ 24,000 = 0.30 ACH | Higher airflow may increase ventilation energy, sound or conditioning load; designer must evaluate | | 90 cfm | 32,000 ft³ | 90 × 60 ÷ 32,000 = 0.169 ACH | Same flow produces a different result in a larger volume; do not copy an old rate into a new plan | The source-to-control row would then read: seasonal wildfire-smoke concern → whole-home and refuge-room strategy → envelope and intake review, compatible filtration, normal and exception ventilation modes, portable-cleaner option → architect and HVAC designer → envelope notes, mechanical schedule and owner manual → design record, equipment submittal and startup instructions → decide whether the refuge room, backup power or additional operational instruction is required. The point is not the 0.225 figure. The point is that a homeowner can show the design team the input, unit, formula and sensitivity, then ask for a professional answer. Never claim the example represents a measured home, a completed design or the effect of a particular filter. ### 5. Materials and flush-out are part of the handoff If the household has a preference for low-emission or low-odor materials, express it as a submittal and record requirement. Identify flooring, adhesives, cabinets, coatings, sealants, insulation, furniture built into the home and any products stored on site. Ask who can approve substitutions, what product document is retained and whether the home will be ventilated before occupancy under the project’s plan. EPA describes Indoor AirPlus as addressing material choices, protection from weather damage and ventilation before move-in. The [EPA Indoor AirPlus features page](https://www.epa.gov/indoorairplus/benefits-and-features-indoor-airplus-homes) supports that program-level framing. It does not say that a generic “green” label proves suitability for this household, nor does it resolve every odor or chemical concern. The brief should say: - Which products need homeowner approval before ordering. - Which records are required: manufacturer, product name, lot or model if relevant, certification or disclosure document when the project relies on one, and installed location. - Who checks that stored materials are protected from weather and contamination. - Whether the builder has a pre-occupancy cleaning, ventilation or flush-out sequence, and how it will be documented. - What the homeowner should expect on move-in day, including which odors may persist and which signs require the builder or designer to investigate. Do not promise that a material selection prevents all chemical exposure or guarantees a health outcome. Use the material requirement to create a traceable decision and substitution process. ![Comparison of ventilation and filtration choices with airflow, pressure, maintenance and smoke-mode tradeoffs](https://brictale.com/images/home/build/design/prepare-new-home-indoor-air-quality-brief-before-schematic-design/ventilation-filtration-tradeoffs.webp) ## Assign responsibility and place every decision in the design set Make the homeowner the decision owner and make technical responsibility explicit by discipline. A handoff matrix is useful only if it distinguishes “consulted,” “responsible for design,” “responsible for installation,” “responsible for verification” and “responsible for operation.” A logo, label or checklist cannot replace that assignment. ### Role boundaries **Homeowner.** Supplies household routines, priorities, budget and acceptable tradeoffs; provides known records; chooses whether an unresolved risk is acceptable; approves the brief; keeps the operating and maintenance records after handover. The homeowner does not certify code compliance or perform hazardous testing. **Architect or designer.** Coordinates the brief with the plan, room relationships, enclosure concept, material schedule, garage separation, equipment locations, service access and drawing/specification set. The designer should flag where a choice requires engineering, specialized testing or AHJ confirmation. **HVAC or mechanical designer.** Develops the equipment, distribution, filtration, ventilation, exhaust, pressure and control strategy; verifies compatibility with manufacturer limits and the project’s adopted requirements; identifies what is measured or commissioned at startup. The homeowner should ask for design assumptions and maintenance access, not just equipment model names. **Builder.** Converts the design into construction means and sequence, protects materials and ducts, coordinates penetrations and substitutions, maintains job-site cleanliness, records concealed work and delivers the agreed records. EPA warns that construction dust can enter ducts and equipment even when the system is not running. See [EPA’s duct-protection bulletin](https://www.epa.gov/sites/production/files/2020-06/documents/2019.07_tech_bulletin_duct_protection_during_construction.pdf). **Rater, verifier or commissioning professional.** Performs only the checks within the agreed scope and credential or program framework, records results and identifies failures or exceptions. A rater’s checklist is not a universal guarantee and is not automatically a substitute for a licensed design professional or AHJ inspection. **Qualified trades.** The electrician, plumber, insulation installer, enclosure specialist, radon professional or other trade performs work and tests within the relevant license, training and contract scope. Assign one person to coordinate records so the homeowner does not have to reconstruct the chain later. **Authority having jurisdiction.** The named city, county, state, tribal or other permitting authority with authority over this project determines how adopted codes, amendments, permits and inspections apply. The jurisdiction must be written into the project record. A national EPA or DOE page cannot tell you which local edition or amendment applies to an unnamed parcel. ### Where the decisions belong Do not leave the brief as a standalone PDF no one uses. Add a destination for each row: | Decision | Minimum design destination | Construction destination | Handover destination | |---|---|---|---| | Outdoor-air intake and exhaust relationship | Mechanical plan and equipment/control schedule | Installed location and penetration record | Operating mode and maintenance instructions | | Filter goal and access | Mechanical plan, filter schedule and equipment submittal | Cabinet installation and seal check | Filter size, rating, access and replacement record | | Kitchen and bath exhaust | Floor plan, reflected ceiling plan and mechanical notes | Fan, duct, termination and control installation | Functional operation and cleaning instructions | | Moisture and foundation strategy | Site, foundation and enclosure details | Photos or inspection records before concealment | Drainage and humidity maintenance guidance | | Garage separation | Plan, wall/door schedule and penetration details | Door, seal and penetration inspection | No-idling/storage instructions and maintenance record | | Radon path | Foundation detail and project scope | Location and continuity record if included | Test result, mitigation record or open follow-up | | Material and substitution rules | Finish/material schedule and submittal procedure | Product records and protected storage | Product list and cleaning/maintenance instructions | | Construction dust protection | Construction IAQ or QA/QC plan | Covered openings, clean site, cleaning and filter change | Duct/equipment cleaning record and new filter record | The source of truth should be named: drawing number, specification section, submittal log, change order, inspection form, test report, owner manual page or decision log entry. If a control exists only in a meeting memory, it is not yet part of the design. ### The change-control rule Every substitution that can alter air, moisture, combustion, pressure, emissions or maintenance must reopen the relevant row. This includes a different window or enclosure assembly, a moved air handler, a smaller filter cabinet, a different range hood, a new fireplace, a garage-to-house door change, a finish substitution, a revised foundation or a different ventilation control. Use a five-line change record: 1. Proposed change and reason. 2. Concern or source affected. 3. Technical reviewer and date. 4. Drawing, specification and operating record updated. 5. Verification gate added, removed or changed. The homeowner may require review or reject an unreviewed change when the contract gives the homeowner that approval right, even when the change appears cheaper or faster; otherwise, follow the contract’s change process and ask the responsible professional how the applicable jurisdictional and technical requirements are handled. The project team can propose an equivalent alternative, but “equivalent” must state equivalent for what: pressure, filtration, moisture, emissions, durability, access, noise, code or program verification. ## Protect the design during construction and handoffs Carry the IAQ brief into procurement, construction sequencing and handover, because a sound design can be undermined by open ducts, wet materials, uncontrolled substitutions, missing seals, dirty equipment or undocumented changes. The builder should own the construction IAQ or QA/QC plan, while the homeowner tracks whether the promised evidence is being collected. ### Before the first dusty work Agree on a construction protection plan before HVAC equipment and ducts are vulnerable. EPA’s duct-protection bulletin says new construction dust from sawing, sanding and drywall can enter ducts and equipment even when the system is not operating. It recommends sealing duct ends and register boots until construction is completed, keeping the site clean, cleaning ducts and air-handling equipment after construction, and replacing filters. Read the exact [EPA duct-protection guidance](https://www.epa.gov/sites/production/files/2020-06/documents/2019.07_tech_bulletin_duct_protection_during_construction.pdf). Put these items in the builder’s plan: - When the air handler, ducts, grilles and outdoor-air connections are installed relative to dusty work. - What covers or protection are acceptable and how they remain visible. - Who checks that covers do not create trip hazards or block required access. - When the system may be energized and when it may not run during dust-generating work. - How the site is cleaned, including vacuuming rather than redistributing fine dust. - What cleaning is performed before startup, by whom and with what record. - Which filter is installed for startup and which filter is delivered for occupancy. - How the builder prevents wet or weather-damaged materials from being concealed. - How substitutions and damaged materials are reported to the designer and homeowner. Do not walk an active construction site without the builder’s permission and required protective equipment. Avoid open floors, ladders, roofs, excavations, crawlspaces, electrical panels, gas equipment and confined mechanical areas. Photos should be taken from safe, permitted locations; the builder or qualified inspector should document concealed work when the homeowner cannot safely observe it. ### Handoff 1: homeowner to designer The homeowner sends the input ledger, room prompts, preferences and non-negotiable constraints. The designer returns a marked-up brief that distinguishes: - Accepted design input. - Input needing technical interpretation. - Input that needs a site or specialist investigation. - Input that conflicts with another requirement. - Input deferred to a later design stage, with a date and owner. The handoff is complete only when the designer confirms where the brief appears in the schematic set or decision log. A verbal “we will keep that in mind” is not a closed handoff. ### Handoff 2: designer to HVAC designer and builder The designer passes room occupancy, source locations, adjacency, window and envelope assumptions, garage relationship, equipment-space constraints, filter-access requirement, exhaust locations and the household’s operating priorities. The HVAC designer returns airflow, pressure, equipment, filter, ventilation, exhaust, controls, noise, condensate and maintenance assumptions. The builder confirms what can be sequenced, protected, inspected and documented. The homeowner should look for contradictions: - A filter requiring service access that the floor plan blocks. - A range hood that discharges where an intake could draw pollutants. - An exhaust strategy that changes the pressure assumptions for a combustion appliance. - A mechanical room whose temperature or moisture conditions do not match the equipment requirements. - A “quiet” ventilation promise with no control or sound assumption. - A low-emission material requirement with no substitution approval procedure. - A garage separation detail that does not include penetrations, doors and shared pathways. ### Handoff 3: builder to verifier and homeowner The builder provides the current plans, approved submittals, change records, protected-duct record, concealed-work photos or inspections, equipment records, cleaning and filter records, startup information and outstanding items. The rater or verifier checks only the agreed scope and records pass, fail, not applicable or unresolved. The homeowner receives a plain-language operating record. If a record is missing, do not call the feature verified. Call it “unverified,” assign an owner and decide whether the next gate is blocked. That language protects the project from converting an absence of evidence into a claim of performance. ## Verify before concealment, startup and occupancy Use three verification gates—design release, pre-concealment and startup/handover—because different evidence exists at different times. A final walk-through cannot recover every concealed condition, and a program label cannot answer a question that was never assigned or documented. ### Gate A: schematic design release At this gate, verify decisions and responsibilities, not installed performance. The homeowner should receive a marked-up brief showing: - Site and household inputs, with unknowns labeled. - Room-by-room source and control rows. - Foundation, moisture, radon and garage questions assigned. - Ventilation, exhaust, filtration and exception-mode questions assigned to the HVAC designer. - Material and substitution rules. - Construction protection owner. - Local jurisdiction and AHJ identified, with code questions assigned. - A list of unresolved items that block design approval versus items that can safely continue to detailed design. The design release should answer: “Can the designer draw the next set without silently assuming away a material IAQ risk?” If not, return the brief for revision. ### Gate B: pre-concealment This is the last practical moment to record many enclosure, foundation, penetration, duct, drain, garage and material conditions. Define the exact inspection window for each item. Ask the builder what will be visible, what will be photographed, what will be inspected by a qualified person and what evidence will be retained. Useful evidence may include: - Dated photographs with a drawing reference and orientation. - Approved product submittals and substitution approvals. - Inspection or rater forms within their stated scope. - Duct protection and cleaning records. - Foundation or water-management inspection records. - Air-sealing, duct-sealing or pressure-test results if included in the contract or program. - Radon-resistant construction record or professional testing plan where applicable. - A list of anything not inspected and the decision made about it. Do not treat a photograph as proof of hidden continuity unless the photo actually shows the relevant condition and a qualified reviewer accepts it. Do not crawl under a building or enter an excavation to obtain a picture. Do not handle suspected mold, contaminated soil or unknown debris. ### Gate C: startup and handover At startup, verify the system as installed and instructed, not as imagined in the brief. Ask for: - Equipment model and location records. - Filter size, rating, cabinet seal and access instructions. - Ventilation control settings, normal mode and exception mode. - Exhaust fan operation and discharge route records within the agreed scope. - Combustion and carbon monoxide safety checks by qualified professionals when combustion equipment exists. - Condensate drainage and humidity-control instructions. - Duct and equipment cleaning record after construction. - Material and substitution record. - Owner manual and maintenance schedule. - Open-item list with owner and due date. EPA’s filtration bulletin says filters should be accessible and replaced or cleaned frequently because a dirty, clogged filter can reduce airflow. Use the [EPA filtration bulletin](https://www.epa.gov/sites/production/files/2020-06/documents/2019.11_tech_bulletin_filtration.pdf) as a prompt for access and maintenance, not as a universal calendar interval. ### What evidence does not prove Avoid four common leaps: - A MERV rating does not prove the filter is compatible with the blower or that the whole home has clean air. - A tight-envelope goal does not prove wildfire smoke cannot enter; EPA says it may not completely eliminate entry. - A radon-resistant feature does not equal a radon measurement or a guarantee of a low result. - A ventilation system’s existence does not prove the intended airflow, pressure, control sequence, maintenance or exception mode. The brief should teach the team to say “this record proves this limited thing.” That is more useful than a broad claim no record can support. ![Three IAQ verification gates from schematic release through pre-concealment to handover](https://brictale.com/images/home/build/design/prepare-new-home-indoor-air-quality-brief-before-schematic-design/iaq-verification-gates.webp) ## Resolve exceptions and make the schematic-design decision Resolve an exception by stating the risk, the available choices, the tradeoff, the authority who must accept it, the verification plan and the next decision date. Do not hide an exception in a general note or allow a narrow budget decision to erase the original household priority. ### Failure branch: the site risk is unknown If the owner knows a concern exists but has no reliable site information—such as radon context, drainage, contamination or wildfire exposure—mark the row “unknown,” identify the appropriate local, environmental or design professional, and decide whether schematic design can proceed with a reversible assumption. Do not invent a low-risk conclusion from silence. The next decision might be to commission a site investigation, obtain public records, move the foundation concept forward with a protective allowance, or pause the affected portion of design. ### Failure branch: the desired filter will not fit If the homeowner requests a higher-MERV filter and the HVAC designer reports excessive pressure, do not instruct the installer to force it into the existing cabinet. Reopen filter area, cabinet depth, duct sizing, blower limit, replacement access, portable-cleaner option and the source-control strategy. EPA specifically notes the airflow restriction tradeoff and the need to size the system and filter slot accordingly. The next decision is a documented comparison, not an unsupported yes-or-no promise. ### Failure branch: the ventilation plan conflicts with smoke mode If the normal ventilation approach brings outdoor smoke into the home, define the temporary operating mode before occupancy. Ask what indoor sources need control while outdoor air is reduced, how the homeowner knows when to resume, what alarms or combustion systems must remain operational and what local emergency guidance controls during the event. EPA’s wildfire guidance says additional steps may be necessary during extreme events; the project manual should be specific to the installed system. ### Failure branch: the attached garage becomes a workshop If the garage changes from vehicle storage to woodworking, painting, battery work or another emission-producing activity, reopen the source-control and separation rows. Do not assume the house’s central HVAC filter or a door seal makes the activity acceptable. The project may need a different location, dedicated ventilation, storage strategy, pressure review, electrical design and local approval. The homeowner should make this decision before the plan is fixed. ### Failure branch: material substitutions arrive late If a specified product is unavailable, identify what the original choice was controlling: emissions, moisture response, durability, cleanability, fire or another characteristic. Require the proposed substitute and its evidence to be reviewed by the accountable designer before installation. If the substitution changes an IAQ assumption, update the row, drawings, submittal log and handover records. ### The final schematic approval checklist Sign the brief only when the following statements are true or explicitly marked open with a blocking decision: - The project jurisdiction is named as a city, county, state, tribal or other actual AHJ, and no local rule is being generalized from a national source. - The household’s routines, sensitivities and unacceptable sources are recorded without medical or performance guarantees. - Site observations, documents, measurements and unknowns are labeled separately. - Outdoor pollutants, moisture, radon context, combustion, garage sources, materials and construction dust have rows. - Every affected room has a source, control, access and maintenance discussion. - Ventilation, filtration, exhaust, pressure and enclosure decisions are coordinated by qualified designers. - Any modeled calculation shows inputs, units, formula, sensitivity and the fact that it is illustrative. - The desired controls appear in a drawing, schedule, specification, submittal procedure or decision log. - The responsible person for design, installation, verification and operation is named. - Pre-concealment evidence and startup evidence are defined before the work is covered. - Open risks state what can proceed, what is blocked and when the next decision occurs. - The homeowner has a handover record that explains normal operation, exception mode, filter access, maintenance and who to call when an observed problem falls outside the manual. ### A compact approval record Use this final record at the meeting: | Field | Entry | |---|---| | Project and jurisdiction | Parcel or project name; city/town; county if applicable; state; named AHJ | | Stage | Pre-schematic design; date; next approval date | | Decision owner | Homeowner name or household decision group | | Technical leads | Architect/designer; HVAC/mechanical designer; builder; rater/verifier; specialist contacts | | Highest-priority concerns | Three to five concerns stated as sources and affected rooms | | Accepted controls | Controls approved for schematic development | | Blocking unknowns | Unknown, owner, evidence needed and due date | | Verification gates | Design release; pre-concealment; startup/handover evidence | | Operating tradeoffs | Noise, maintenance, energy, smoke mode, access and budget choices | | Approval | Homeowner decision; professional follow-up; AHJ or permit question | The right next decision is often narrower than “approve the house.” For example: approve the room adjacencies while holding the kitchen exhaust and garage separation for the mechanical review; approve the foundation concept subject to radon and moisture input; or approve the ventilation comparison only after the designer returns pressure, sound, maintenance and smoke-mode assumptions. Narrow approvals keep the project moving without disguising an unresolved safety or performance question. ## Keep the brief alive through construction and ownership Keep the approved brief as a living decision record through construction, startup and the first maintenance cycle. The homeowner should compare the handover record with the original priorities, record every exception, and make the next professional conversation specific rather than starting from a vague report that “the air feels wrong.” ### First 30 days of ownership After occupancy, use the manual and records to learn the system without changing safety settings. Record date, room, activity, outdoor condition, control mode, filter condition, visible moisture, odor or comfort observation, and the action taken. These are homeowner observations, not diagnostic results. Escalate promptly when there is: - A carbon monoxide alarm, combustion alarm, smoke alarm or other life-safety warning. - Suspected fuel or combustion-gas odor, uncontrolled exhaust, water intrusion, sewage, visible mold-like growth, electrical overheating or a damaged filter cabinet. - Persistent moisture, condensation, unexplained pressure problems, repeated system trips or a ventilation control that will not operate as instructed. - Wildfire smoke or another emergency event for which local officials issue instructions. Leave the area and contact emergency services or the appropriate qualified professional when the situation may be immediately dangerous. Do not troubleshoot gas, electrical, combustion venting, contaminated material or confined spaces remotely or by trial and error. ### The maintenance handoff The owner manual should state who maintains each item, how to reach it, what evidence to retain and what happens if it fails: | Item | Owner action | Professional action | Record to retain | Failure trigger | |---|---|---|---|---| | Central filter | Inspect and replace or clean using the installed system’s instructions | Confirm cabinet, seal and airflow when service is needed | Filter size/rating and dates | Dirty filter, reduced airflow or inaccessible cabinet | | Ventilation system | Run normal mode; understand smoke exception mode | Service, balance or troubleshoot within scope | Settings and service record | Control failure, unusual noise or persistent odor | | Kitchen and bath exhaust | Use during source-producing activity and clean accessible parts | Inspect fan, duct and termination if performance is poor | Model, route and service notes | Moisture remains, poor capture or backdraft concern | | Drainage and condensate | Keep visible drains and discharge paths clear | Repair leaks or blocked lines | Service record | Water, staining, overflow or recurring humidity | | Garage separation | Keep door closed as intended; follow storage and no-idling rules | Repair seals, penetrations or pressure-related issues | Repair record | Odor transfer, damaged seal or changed use | | Radon strategy | Follow the agreed test or monitoring plan | Test or mitigate by qualified radon professional | Test and mitigation documents | Result or condition exceeds the professional’s action plan | This schedule is not a substitute for the manufacturer’s instructions, a professional service plan, public-health advice or the actual local requirement. It is a way to ensure the handover conversation has an owner and record for every design decision. ### The brief’s final test The brief succeeded if a future homeowner, builder, rater or service professional can answer four questions without reconstructing the project from memory: 1. What were we trying to control, and why did it matter to this household and site? 2. What was installed or agreed, and where is the evidence? 3. What are the normal and exception operating instructions? 4. What remains uncertain, who owns it and what should happen next? That is the practical bridge between authoritative IAQ guidance and a real schematic-design decision. It respects the limits of national program documents, makes jurisdiction-specific questions visible, gives qualified professionals the inputs they need and keeps the homeowner in control of tradeoffs without asking the homeowner to perform engineering, testing or hazardous work. ## Evidence - EPA Indoor AirPlus Version 2 includes design, construction and verification requirements, and EPA publishes separate builder-responsibility and verification-checklist documents. [Indoor AirPlus Program Documents | US EPA](https://www.epa.gov/indoorairplus/indoor-airplus-program-documents). Scope: U.S. EPA Indoor AirPlus program documentation; a voluntary program framework and its current published documents, not a universal building code or project-specific permit determination.. Accessed: 2026-09-08. - EPA identifies indoor pollutant sources as a primary cause of indoor-air-quality problems and explains that inadequate ventilation can increase pollutant levels by failing to dilute or remove contaminants; temperature and humidity can also affect concentrations. [Protect Indoor Air Quality in Your Home | US EPA](https://www.epa.gov/indoor-air-quality-iaq/protect-indoor-air-quality-your-home). Scope: EPA consumer guidance for homes, including new single-family homes; general source-control and ventilation guidance, not a project-specific ventilation rate or medical diagnosis.. Accessed: 2026-09-08. - EPA describes Indoor AirPlus features addressing moisture, radon in high-radon-potential areas, HVAC design and installation, combustion venting, garage pollutant control and carbon monoxide alarms; EPA says the specifications reduce indoor pollutant sources by using materials with fewer chemicals, protecting materials stored on-site from weather damage and ventilating the home before move-in. [Benefits and Features of Indoor AirPlus Homes | US EPA](https://www.epa.gov/indoorairplus/benefits-and-features-indoor-airplus-homes). Scope: EPA description of the ENERGY STAR plus Indoor AirPlus labeled-home package; program features and benefits, not a promise that every home or local code includes each measure.. Accessed: 2026-09-29. - EPA says a tighter building envelope can reduce wildfire-smoke entry but may not eliminate it, and says additional measures may be needed during extreme wildfire events. [Indoor AirPlus and Wildfires | US EPA](https://www.epa.gov/indoorairplus/indoor-airplus-and-wildfires). Scope: EPA guidance for U.S. homes during wildfire-smoke events; not a guarantee of smoke-free indoor air and not a substitute for local emergency instructions.. Accessed: 2026-09-08. - EPA's wildfire guidance states that Indoor AirPlus requires at least MERV 8 in central forced-air HVAC systems and highly recommends MERV 13 for added protection; it also notes that ductless or hydronic systems may need portable air cleaners when a high-efficiency HVAC filter is unavailable. [Indoor AirPlus and Wildfires | US EPA](https://www.epa.gov/indoorairplus/indoor-airplus-and-wildfires). Scope: EPA guidance and Indoor AirPlus program scope for central forced-air systems and alternatives; filtration compatibility remains a project-specific HVAC design question.. Accessed: 2026-09-08. - During a wildfire event, EPA says occupants can temporarily turn off mechanical ventilation to reduce wildfire-smoke entry and resume normal ventilation after the event to help dilute indoor air contaminants; EPA also says homeowners or building managers should discuss strategies that differ from normal operation and that additional measures may be needed during extreme events. [Indoor AirPlus and Wildfires | US EPA](https://www.epa.gov/indoorairplus/indoor-airplus-and-wildfires). Scope: EPA guidance for U.S. homes during wildfire-smoke events; operating instructions remain specific to the installed system, combustion and life-safety controls, and local emergency guidance.. Accessed: 2026-09-29. - EPA's filtration bulletin explains that higher-MERV filters can restrict airflow, so the ducts, filter box and blower limit must be considered; it recommends an accessible, sealed filter location and replacement or cleaning when dirty. [Indoor airPLUS Technical Bulletin: Filtration | US EPA](https://www.epa.gov/sites/production/files/2020-06/documents/2019.11_tech_bulletin_filtration.pdf). Scope: EPA Indoor AirPlus technical bulletin; design guidance for filter selection and maintenance, not a substitute for HVAC design calculations or manufacturer limits.. Accessed: 2026-09-08. - EPA warns that construction dust and debris can enter ducts and equipment even when HVAC is off, recommends protecting duct openings until dusty work is complete, and calls for duct and equipment cleaning plus filter replacement after construction. [Indoor airPLUS Technical Bulletin: Duct Protection During Construction | US EPA](https://www.epa.gov/sites/production/files/2020-06/documents/2019.07_tech_bulletin_duct_protection_during_construction.pdf). Scope: EPA construction guidance for new homes; implementation must be coordinated with the builder and HVAC contractor and must not create trip or access hazards.. Accessed: 2026-09-08. - DOE's Efficient New Homes training presents a high-performance home as a system that combines an insulated and air-sealed enclosure with water management, comfort and indoor-air-quality protections, with important requirements verified through rater checklists. [DOE Efficient New Homes Single Family Version 2 (Rev. 3) Web Transcript | U.S. Department of Energy](https://www.energy.gov/cmei/buildings/doe-efficient-new-homes-single-family-version-2-rev-3-web-transcript). Scope: DOE Efficient New Homes Single Family Version 2 training and certification context; program requirements vary by building type, location and permit date and do not replace the adopted requirements of the actual jurisdiction.. Accessed: 2026-09-08. - DOE Building Science Education identifies bulk water, capillary movement, air-carried moisture and vapor dispersion as distinct moisture transport paths, and says control depends on climate, insulation and construction type. [Building Enclosure: Building Science - Intro Moisture Flow | DOE Building Science Education](https://bsesc.energy.gov/energy-basics/building-enclosure-building-science-intro-moisture-flow). Scope: DOE building-science education for enclosure and moisture-flow concepts; general principles only, not a project-specific hygrothermal analysis or code interpretation.. Accessed: 2026-09-08. - A Lawrence Berkeley National Laboratory review of 38 studies reports that smart-ventilation strategies can produce energy savings in some cases without compromising IAQ, while some cases showed energy overconsumption; performance depends on the control strategy and context. [Smart ventilation energy and indoor air quality performance in residential buildings: A review | Lawrence Berkeley National Laboratory](https://bies.lbl.gov/publications/smart-ventilation-energy-and-indoor). Scope: Peer-reviewed 2018 review summarized by Lawrence Berkeley National Laboratory; findings across studies and systems, not a guarantee for a particular residence or a replacement for design and commissioning.. Accessed: 2026-09-08.