Adopted by MIAQC Board of Directors on October 14, 2011

 Document Outline:

Introduction & Guiding Principles

General Concern for Residential Air Quality in Maine

Document Purpose

Guiding IAQ Principles

 Prior to the Renovation

Evaluate the Project for Existing Conditions

Moisture Inspection

Assessing Ventilation

Lead and Lead Testing

Radon and Radon Testing

Asbestos and Asbestos Testing

Protect Occupant Health During Renovations

Demolition, Disposal & Recycling

 Renovations by Project Type


New Roof

Window & Door Replacement and Repair

Siding/Cladding Replacement

Changing, Replacing or Supplementing Heating Systems


Renovating a Basement


Bathrooms & Kitchens

Garage Additions/Retrofits

Major Additions/Expansions



General Concern for Residential Air Quality in Maine

In Maine, and throughout the country, we are increasingly confronted by the realization that our homes can be harmful to our health. The risk of health effects from indoor environmental pollutants is a serious public health concern, both for the general population, as well as for those populations that spend more time in the residential environment: infants, young children, the elderly, and those with chronic illnesses. Maine residents face exposures to radon, carbon monoxide, lead, asbestos, mercury, tobacco products, pesticides, pressed wood products, and biological contaminants. Air quality in homes can be severely compromised by improper renovations, poorly executed energy efficiency design, improper use of humidifiers, unvented heating devices, and poor cleaning and maintenance practices. Health problems associated with poor indoor air quality range from general symptoms of malaise (headaches, fatigue, irritability, nausea, dizziness, diminished ability to concentrate) to problems with asthma, sinusitis and other respiratory diseases. Short term exposure to carbon monoxide can be life threatening.  Elevated cancer risks are associated with long term exposure to radon and asbestos.  Elevated exposures to lead or mercury can produce serious irreversible damage to developing organ systems, such as the nervous system.

Document Purpose

The purpose of this document is to highlight the practices that should be used during typical residential renovation projects to minimize the likelihood of poor air quality in a residential property. It is in checklist format, and is meant to be used in conjunction with other, more comprehensive building science resources. The checklist has been organized by those renovations most likely to be undertaken in Maine residential properties.


Examples of outside resources include

Energy & Environmental Building Association’s Builder’s Guide to Cold Climates. Published with support from the U.S. Department of Energy’s Building America Program. See www.eeba.org .

  • US EPA Healthy Indoor Environmental Potocols for Home Energy Upgrades epa.gov/iaq
  • S. Environmental Protection Agency Indoor Environments Program. See www.epa.gov/iaq
  • Department of Energy, “Lead Safe Weatherization (LSW) – Additional Materials and Information,” Weatherization Program Notice 09-6, January 7, 2009
  • Maine Home Performance with ENERGY STAR Program (mainehomeperformance.org)
  • American Society of Heating, Refrigerating & Air Conditioning Engineers (ASHRAE): ASHRAE 62.2, 2007 – Ventilation in low-rise residential buildings

Guiding Principles of This Document:

There are a number of key guiding principles that apply to indoor environments, in existing as well as new residential construction.

  1. There is a well-established link between indoor pollutants and occupant health.

(See the MIAQC policy statement on the health basis for recommendations).

  1. The principles for achieving a healthy residential indoor environment are clear. The goal is
    an environment that is:
  • Clean
  • Dry
  • Pollutant and pest free
  • Ventilated
  • Comfortable

(See the MIAQC policy statement on Indoor Air Quality)

  1. The methods to achieve these goals may vary, the primary tools are:
  • Prevention or elimination of pollutants (source control)
  • Proper ventilation within the living space
  • Temperature and humidity control
  • Proper operation of the structure by the building owner
  • Proper use of the structure by the building occupants

(See the MIAQC policy statement on Indoor Air Quality)

  1. There is a direct relationship between energy-efficiency measures and indoor air quality in the residential construction process. (See the MIAQC policy statement on energy efficiency and indoor air quality)
  2. Individual building components and subsystems must be considered collectively in terms of their interaction with each other and their joint IAQ impact on occupants and building performance. Failure to consider these interactions increases the risk for structural issues and systems failures that can result in health and safety concerns for residents. (See the MIAQC policy statement on a Whole Building Approach to Indoor Air Quality)
  3. Renovating and maintaining an IAQ healthy home does not necessarily cost more. While some features may initially be more expensive, they are essential for the health of the residential occupant, and have long-term value for energy efficiency and increased comfort. The recommendations that follow should never be sacrificed due to expense
  4. Renovating an IAQ healthy home requires the equal involvement of the builder (and the builder’s subcontractors), the designer, and the homeowner. 


Prior to any renovation project, evaluate the home for existing conditions that can compromise health and safety.  Specifically, homeowners should look for: 

  • Basements: Wet Basements/dirt floors
  • Water Damage: Pre-existing water damage or leaks in exterior walls and roof (1)
  • Ventilation: Available Ventilation (operable windows, operable fans, balanced systems) (2)
  • Lead: Lead paint (interior and exterior paint in pre-1978 homes) (3)
  • Radon: Radon (test for radon in air and well water) (4)
  • Asbestos: Asbestos (boiler and pipe insulation, vermiculite insulation, flooring, and exterior shingles)
  • Pests: Insect damage and pest infestations
  • Combustion: Properly operating and maintained combustion appliances (furnaces, boilers, stoves, supplemental heating devices) (6)

Identifying these issues in advance of a renovation project will insure that health and safety are not compromised through improper renovation practices (such as sanding/scraping lead paint or disturbing asbestos-containing building materials).  Identifying these issues in advance will also provide the homeowner the opportunity to incorporate proper mitigation of these problems into any home renovation plan, thus minimizing time, effort, and above all, expense.


Maine Radiation Control Program – www.maineradiationcontrol.org.  Has information and resources for Maine homeowners, plus lists of registered radon testers, laboratories, and mitigators.

Maine Department of Environmental Protection – Bureau of Remediation and Waste Management.  Maine DEP manages both the asbestos and lead programs for the state of Maine.  Their website contains helpful links and guidance for homeowners, along with lists of certified lead and asbestos remediation professionals.

U.S. Environmental Protection Agency:  www.epa.gov/iaq.  Website contains practical information and guidance about many indoor environmental pollutants.

  1. Basements, Leaks and Water Damage


IAQ Concern:  Liquid water and chronic moisture problems in homes cause building rot and risk of mold growth.  Mold exposure is associated with cold-like symptoms (sinusitis, rhinitis), and is a common asthma trigger.  Moisture issues should be identified, managed, and repaired prior to a renovation.

  • Conduct a moisture inspection prior to a renovation, and annually throughout the home.  Check the following areas for wet spots, condensation, leaks or water stains (often an indicator of past leaks).  Insects and insect damage may also be a sign of water damage.
    • Plumbing under sinks and in the basement
    • Windows and doors
    • Around tubs, showers, sinks, and toilets
    • Roofs and attics
    • Ceilings and walls
    • Carpets
    • Washing machine connections
    • Basements and crawlspaces
  • Prevent moisture from entering the building.
    • Ensure good drainage around the building
    • Gutters and downspouts should be connected and clear of debris
    • Grade soil away, not towards the building
    • Test drainage with a hose
    • Vent clothes driers to the outside
    • Insulate cold water piping
    • Install kitchen/bath fans that are vented to the outside
    • Dehumidify chronically damp areas, such as basements and crawlspaces
  • Repair any leaks that let water into the building.
    • Repair any plumbing leaks, including tightening clamps on washing machine connections.
    • Seal, caulk, and replace broken glass on old windows to minimize air leakage, or replace with new windows.
    • Replace any drywall, insulation, carpet/pad, and (if necessary) woodsurfaces that have been wet for more than 48 hours.

 2. Assess Adequate Ventilation


All livable spaces within a home should be ventilated.  Ventilation can be found in three forms:


  1. Passive Ventilation – Fresh air and exhausting of pollutants through the use of openable windows, and air infiltration through leaks and cracks.


  1. Exhaust-only ventilation – mechanically exhaust pollutant sources through use of bathroom fans, kitchen fans, dryer vents. Fresh air comes in through natural air infiltration (leaks, cracks, windows)


  1. Balanced Ventilation – controlled provision of fresh air and exhaustion of pollutants through ducted mechanical systems.


Of these options, Balanced Ventilation is preferred.


Resources:     Available Ventilation Standards:




  1. Lead and Lead Testing:


IAQ Concern: Lead is a poison that affects the nervous system.  Young children under six are at the highest risk of lead poisoning.  Lead dust can be created through normal activities—such as opening and closing doors and windows with lead paint on the frame—or from disturbing painted surfaces during renovations. 

  • Assess: Assume lead is present in all pre-1978 homes, or test surfaces with an EPA-Recognized Testing Method..
  • Minimize Dust: Take precautions to limit dust generation, no dry sanding, burning (i.e.heat guns over 1100oF), or use of power equipment without HEPA shrouds)
  • Contain: Isolate work area from rest of home
  • Protect: Use disposable boot covers and HEPA vacuum all clothing before leaving the work area.
  • Clean: Do thorough dust clean up, including HEPA vacuuming and wet washing at conclusion of job.
  • Test: Do clearance dust testing after job completion
  • Training: Hire an EPA-certified Lead Safe Renovator

See the MIAQC fact sheet on lead for additional information and resources on managing lead paint and lead dust in a home.

  1. Radon and Radon Testing:

IAQ Concern: Radon is prevalent in the soil and groundwater throughout Maine. It is the second leading cause of lung cancer behind smoking, and could be present at unacceptable levels in any building.

  • Test: If your home has never been tested for radon, test for radon before any renovation of the basement or building shell.
  • Retest: Test for radon after weatherization
  • Air & Water: Test both the air and the water when your water comes from a well.
  • Mitigate: Incorporate a radon mitigation strategy into your renovation project when radon test indicates mitigation is necessary or recommended.

See the MIAQC fact sheet on Radon in Indoor Air for additional information about radon in Maine homes.

  1. Asbestos and Asbestos Testing

 IAQ Concern:  Asbestos is made up of microscopic bundles of fibers that may become airborne when asbestos-containing materials are damaged or disturbed. When these fibers get into the air they may be inhaled into the lung. Asbestos exposure may cause serious lung diseases including: asbestosis, lung cancer, or mesothelioma.

Never try to remove asbestos containing building materials yourself. Professional help is almost always necessary.  Extensive and expensive contamination can and usually does occur from improper removal or repair.

Maine DEP, U.S. EPA and OSHA all regulate asbestos.  In Maine, non-licensed persons are prohibited from working with asbestos containing building materials in any property, including their own.  There is one exception: single-family owner-occupants can remove asbestos-containing exterior wall shingles from their own house IF they follow Maine DEP’s required methods.

Building materials that often contain asbestos include:

  • Siding: Exterior cement shingles
  • Roofing: Slate-like roof shingles
  • Plaster: Interior wall and ceiling plaster
  • Vermiculite: Vermiculate insulation (installed before 1991)
  • Pipe Insulation: Boiler and/or pipe insulation
  • VAT: Resilient floor products

Have your home inspected by a Maine DEP-certified Asbestos Inspector if you suspect asbestos materials in your home

  1. Carbon Monoxide and Smoke Alarms

  1. Protect Occupant Health During Residential Renovations:

IAQ Concern: Renovations can create a significant number of pollutants that when inhaled can affect health.  Examples include particulate matter, construction dust, chemical vapors, and carbon monoxide.

  • Chemical Vapors: Substitute less toxic chemicals (e.g., use strippers without methylene chloride, use less volatile paints and stains, use glues without toluene, acrylates, or isocyanates, etc.)
  • Contain: Install plastic sheeting to create “barriers” or “walls” and install exhaust fans to keep contaminants away from others.
  • Isolate: Install barriers (tape) and signs to warn others and to keep them out of the work area.
  • Warn: Provide effective hazard communication training to workers
  • Respirators: Provide adequate respiratory protection to workers as needed to supplement the above.

Resources: www.osha.gov  and  www.cdc.gov/niosh

  1. Demolition, Disposal and Recycling

 IAQ Concern:  Home renovation and construction projects should be done with consideration of the total life cycle costs, including the environmental and health implications associated with demolition and disposal.   Demolition can release asbestos fibers, dusts, and other hazardous air pollutants that could infiltrate back into the home and also affect the surrounding community.

  • DEP: Contact the Maine DEP at 287-2651 or maine.gov/dep/rwm
  • CEO: Contact your local Code Enforcement Officer (CEO)
  • Reuse/Recycle: Consider reusing and recycling building materials where able
  • Sort: Segregate your different types of wastes
  • Disposal: Check with your local waste facility/landfill and hauler prior to the work
  • Burning: Controlled burns by Fire Departments are still considered demolition and put much contamination into the air. Further, there may be insurance issues



Project Types:

  1. Weatherization
  2. New Roof
  3. Windows and Door Replacement
  4. Replacing Cladding
  5. Replacing Heating Systems
  6. Laundry
  7. Renovating a Basement for Living Space
  8. Attics
  9. Bathrooms/Kitchens
  10. Garage Additions and Retrofits to Adjacent Living Space
  11. Additions/Expansions and Major Renovations
  12. Landscaping



  1. Weatherization

IAQ Concern and Benefit: Weatherization projects (insulating, air sealing) change the way air and heat flow through a building.  These changes can cause moisture problems, aggravate pre-existing moisture conditions, and affect the drafting of combustion appliances. When done correctly, however, efforts to improve a home’s efficiency can also provide health and safety benefits, such as increased fire safety, better pest management, and better control over unplanned air flows.


Because of the scope and complexity of home weatherization efforts, this document does not address many of the details for how to accomplish specific weatherization projects.  Rather, attention to the following details will greatly reduce the risk that weatherization improvements will have negative impact on indoor air quality.


  • Energy Audit: Before beginning any weatherization work, conduct an energy audit evaluation with blower door test and infrared scan to assess the baseline building performance and to identify those areas that will have biggest impact on energy use and biggest risk for poor indoor air quality and ventilation.
  • Air Sealing: Insulation must be protected by properly installed air barriers and vapor retarders.  Some insulation products, such as rigid insulation or spray in place foam, create their own air and vapor barriers.  Others will require installation of a separate air barrier/vapor retarder system.
  • Fill Gaps: Insulation must be properly fitted within the wall and ceiling cavities. Gaps will cause cold spots, creating potential for condensation and subsequent mold growth.

Tip:     Make sure insulation is properly fitted into the wall cavities around and behind electrical boxes, and behind wiring.

¨   Insulate: For guidance on selecting appropriate R-value of insulation, refer to state and local codes, (Such as IRC, IECC, NFPA, ASHRAE) and other professional standards.  Regional recommendations for the building site climate should also be considered.

¨   Fill Holes: Holes in air and vapor barriers minimize the efficacy of insulation and create pathways for air and moisture to escape the heated envelope of the building and cause condensation and mold growth.  Proper air sealing around all doors and windows, outlets, fixtures, and other penetrations is critical for both energy efficiency and IAQ.

¨ Test: After the work is completed, do post project performance testing, including a blower door test, a combustion test, and a radon test. If the results of these tests indicate problems, follow the recommended protocols for addressing the individual concerns. More information on weatherization and indoor air quality is available in the U.S. EPA Guidance Document:  Healthy Indoor Environment Protocols for Home Energy Upgrades

  1. 2. New Roof:


IAQ concern: Moisture damage can occur from water leakage through the roof, as well as from air and conductive heat losses from the conditioned space. Barriers to pest intrusion must be intact and continuous.


  • Flashing: Prevent water leaks by properly installing the roofing material, flashings, and membranes so that water flows down, off and away from the home
  • Rain: Efforts should be made to keep home dry during project
  • Roof Ventilation: Properly ventilate a roof, unless it is a “hot” roof (insulated immediately under sheathing but not ventilated). Resources: Builders Guide to Cold Climates; International Residential Code
  • Flashing: Thoroughly flash and seal ALL penetrations (chimney, vent stacks, skylights, etc.).
  • Membranes: Use an adhesive rubber membrane on eaves, valleys, roof to wall intersection, and other penetrations such as skylights and stack vents, prior to installing the roofing material.
  1. Window and Door Repair and Replacement:


IAQ Concern:  Water and air leakage in and around windows and doors can lead to moisture problems and reduce comfort through excessive drafts.  Scraping and trim/window removal can lead to lead exposure problems in older homes.

  1. Window Repairs

¨         Paint: Evaluate the window for presence of lead paint (especially in pre-1978 homes). Follow Maine DEP guidance for proper handling of lead paint.  If hiring a contractor to do the work, hire an EPA-certified Lead-Safe Renovator.

¨         Glazing: Remove any cracked or loose glazing around window panes and replace with new for proper air sealing.

¨         Weights?: If adding new weights, use non-leaded weights. If not reweighting, insulate pocket to prevent cold spots around the frame.

¨         Storms: Check all storm windows for proper air tightness.  Re-caulk if necessary.

¨         Jams: Consider installing vinyl or copper window jams to help windows glide and reduce drafts

  1. Window & Door Replacement:

The primary indoor air quality principle for windows and doors is energy efficiency.  Using energy efficient windows and doors will minimize the amount of cold air that leaks in and reduces the possibility of condensation and resulting mold growth.

  • Low E: Use multi-paned, low-E glass
  • Air Seal: All windows and doors should be sealed and caulked in place.
  • Flashing: All windows and doors should be properly flashed top, bottom, and sides..
  • Weatherstrip: Select insulated exterior doors with good weather stripping

Tip:  Look for windows that have a good ANSI performance rating.

  • Lead: Evaluate existing window for presence of lead paint prior to removal. Follow

guidance for appropriate removal of lead-containing materials.

  • Flashing: Install drip caps
  • Seal: Insulate interior cavity with a proper air barrier system.
  • Coat: Stain and/or seal unfinished wood surfaces to resist moisture absorption

Historic Homes Note:  a well caulked and sealed wood frame window with a properly installed and sealed storm window is an effective alternative to window replacement.


  1. Replacing Cladding (siding):


IAQ Concern:  Improperly applied cladding (siding) can allow moisture to become trapped within the wall components.  All cladding will leak, and should not be considered a functioning part of the drainage plane.  Cladding is primarily an aesthetic, visual detail.  When replacing cladding on an existing home, installing a drainage plane behind the new material is critical for moisture management. If siding is going to be replaced, that is the time to evaluate if additional insulation can be added to the exterior, or the insulation in the walls can be improved.

  • Lead/Asbestos: If existing siding contains lead or asbestos, remove in accordance with available guidance to insure worker safety and prevent contamination of soils around the home.
  • Drainage Plane: A properly installed and sealed drainage plane is essential to prevent water and moisture from leaking into the structure and coming in contact with the frame and insulation of the building. It also serves as the primary means for moisture to flow down, off and away from the building.
  • Air Seal: If house wrap is used as a drainage plane, all seams should be properly overlapped and taped or sealed so that it is continuous.
  • Seal: Penetrations for windows/doors, vent hoods, water spigots, chimneys, and wires must be sealed to the drainage plane and flashed.
  • Flash All windows and doors must be properly flashed and sealed.
  • Drain: For wood and fiber cement siding, create a space between siding and drainage plane (a “rain screen”) to allow for drainage of water down and out, and allow moisture to dry from the back of the siding.
  • Cedar: If using cedar clapboards, back-prime the clapboard to prevent problems with oriented strand board (OSB) or plywood.
  • Pests: Install insect screen at the base of the rain screen to prevent pests from entering the home.

Tip:  Use a capillary break, such as “home slicker” when installing cedar shingles.  Use 1” x 3” vertical strapping when installing clapboards.



  1. Changing, Replacing or Supplementing Heating Systems:


IAQ Concern: Improperly installed and maintained heating systems can leak combustion byproducts into a home, causing serious health effect or even death (carbon monoxide).

  • Combustion Air: Sealed combustion direct-vent heating units are preferred. If installing an atmospheric (non direct-vented) appliance, insure sufficient combustion air. (outside air supply)
  • Ducts: Clean ducts after completion of any dust or particle-producing renovation.
  • Furnaces: If installing a new forced hot air system, place registers in wall, not floor for improved dust control
  • CO Alarm: Install a carbon monoxide detector. Units powered by electrical service with battery back-up are preferred
  • Flues: Inspect all chimney flues for leaks, gaps, and obstructions.
  • CZA Check: Perform combustion safety testing after all work is completed.
  • Seal Ducts: Check ducts for excessive leakage outside of conditioned space
  • Vent Outdoors: All combustion heating units, primary and supplemental, must have proper venting to the outdoors of the combustion by-products
  1. Laundry:

IAQ Concerns: Leaks, exhaust of excess moisture into home, mold growth

  • Vent Outdoors: Always vent dryers to the outside. Use sheet metal ducts and take the shortest and straightest route.
  • Pans: Place pan under the washer and water heater or install a floor drain.
  • No Leaks: Ensure that supply connections are solid, leak-tight, and correct. Use stainless steel braided hoses (less likely to burse than rubber supply hoses.)
  • Discharge: Connect water discharge to disposal system.
  • Make-up Air: Ensure sufficient outside air to prevent depressurization of the house when running the dryer
  1. Renovating a Basement for Living Space


IAQ Concern: Basements can be a constant source of moisture intrusion into the home because of liquid water movement and vapor diffusion through and around the building foundation. Basements also provide easy pathways for soil gasses (such as radon and sewer gas) to enter a home.  Never retrofit a basement for living space unless all moisture and soil gas concerns have first been addressed.


  • Pitch: Make sure exterior grading and drainage slopes out and away from building. Guideline:  4 inches of pitch for every ten feet.
  • Drain Away: Make sure water from gutters and downspouts is directed away from the building either above or below grade.
  • Test: Test for radon, and mitigate if necessary, prior to any basement renovation.
  • Water Seal: Seal all foundation cracks to prevent air and water leakage prior to renovation. Use crack injection if exterior excavation is impractical
  • Cover Sumps: Seal all sump units to prevent radon and moisture intrusion.
  • Insulate: Insulate basement floor with rigid foam if headroom is sufficient and stairs can be reworked. If unable to insulate basement floor, a dehumidification strategy during the summer months will need to be implemented to prevent condensation and mold growth.  Consider using a commercial grade dehumidifier that will be more energy efficient and more effective at removing excess moisture.
  • Insulate: Insulate basement walls with rigid foam impermeable above and permeable below
  • Rock Foundation: Spray foam may work well with clean and dry field stone foundations. Spray foam must be covered with a thermal barrier in accordance with local building codes. Make sure surface water is directed away from home.
  • Insulate: Avoid fiberglass insulation in stud cavities that can be moist,… or ensure that it can dry to the interior quickly
  • Plan for Water Leaks: Account for inevitable water due to gravity:
    • ___No carpeting, removable baseboard, fiberglass wallboard
    • ___Inexpensive flooring, such as paint, VCT may be more suitable
  • Ceiling: Suspended ceiling if possible
  • Ventilate: Insure adequate ventilation in any space that will be occupied by people

8         Attics


IAQ Concern: Poor air sealing between the heated spaces of a home and an unheated attic spaces can lead to long-term water damage, mold growth, roof rot, and ice dams.

  • Air seal: Completely seal all joints and cracks to prevent warm heated air from leaking into an unheated attic space.
  • Hatches: All attic access ways should be completely sealed and insulated
  • Air Seal: If necessary, remove and reinstall or replace existing insulation to facilitate proper air sealing.
  • Vent Out: Make sure all appliances and exhaust fans are vented to the outside, not into the unheated attic space.
  • Attic/Roof Venting: If home has a vented roof, maintain open circulation pathway from soffit vents to ridge/gable/roof vents.
  • Seal/Insulate Ducts: Seal and Insulate any ducts in attic space to prevent heat loss into the unconditioned space and prevent moisture problems. If possible they should be buried in insulation as close to the heated side space as possible.

9      Bathrooms/Kitchens


IAQ Concern: Cooking and bathing are significant sources of moisture in a home.  Fossil-fuel powered appliances can leak combustion by-products into the living space.

  • Hood: Vent kitchen range hood to outside, especially if its gas.
  • Bathrooms: Ventilate bathroom with exhaust-only or balanced ventilation. Balanced ventilation is preferred.
  • Whole House Ventilation: If you can get the home tight enough and eliminate the atmospheric combustion appliances,  creating whole-house ventilation per ASHRAE 62.2-2007 through use of kitchen and bath fans.
  • Hard Surface: Use nonporous/nonabsorbent floorcoverings in high moisture/often wetted areas (not wood, no carpet)
  • Special Moisture Areas: Take particular care to remove excess moisture from areas with indoor hot tubs and steam showers
  • Combustion Air: Ensure exhaust fans do not cause venting problems with combustion appliances.

10    Garage Additions/Retrofits Adjacent to Living Space:

IAQ Concerns: Combustion emissions (including carbon monoxide) from motor vehicles can infiltrate the house, along with pollutants from gas/oil spills and chemicals and lawn mowers stored in garage spaces. There are also risks of fires quickly spreading from the garage to the living space.

  • Fire Separation: Provide fire rated surfaces and doors between garage and living areas
  • Air Seal: Consider the wall between the house and an attached garage as an exterior wall. Insulation, air, and vapor barriers should be installed in the same manner as any other exterior wall so that the garage is “thermally separated” and sealed off from the house, greatly reducing the risk of pollutants in the garage from entering the house.
  • Garage Exhaust: Consider installation of ventilation to exhaust moisture and pollutants or hobby pollutants, especially if children play in the garage. Never run a generator in a garage.

Design Note: Consider designing the garage as a separate building to eliminate the risk of pollutants in the garage from entering the home.

11  Additions/Expansions and Major Renovations

New additions, extensive expansions and major renovations to existing homes are considered new construction.  Please refer to MIAQC’s Recommendation for New Residential Construction


12   Landscaping

IAQ Concern: Landscaping schemes can sometimes contribute to air quality problems in a home.  Plants, shrubs and trees placed too close to the building can contribute to moisture problems and provide easy access points for pests to enter the home.

  • Space: Foundation plantings should be set away from the dripline of the roof and at a minimum of 24 inches away from the foundation at full maturity.

Tip:  Place a two-foot wide strip of pea-stone or non-woody mulch, with landscape cloth underneath, to discourage insect and rodent infestation and prevent vegetation from growing next to the foundation.

  • Trees: Shade trees should be set far enough away from the home to prevent pest access and eliminate foundation damage from root penetration
  • Vents: Exterior vents must be kept free of obstacles
  • Grading: Finish grade should be pitched away and no less than 8” away from any wood surfaces