Tips for Building a Healthy, Energy-Efficient Home
The following recommendations are excerpted from the Maine Indoor Air Quality Council’s full “Checklist for New Residential Construction”, which is available for free on this website at: https://maineindoorair.org/iaq-checklist-for-new-residential-construction/
Building a new home is a big, complex project. The purpose of this article is to highlight the most critical construction tasks that MUST be followed to ensure you end up with a new home that is both healthy for you and your family to live in, as well as energy-efficient. Many of these recommendations can only be done at the point of new construction, or are significantly less expensive to do up front rather than after the home is finished. The added cost of many provisions will save the homeowner in the long run—in reduced energy consumption, reduced maintenance cost, and increased health and productivity.
The Council recommends you not only review these recommendations with your contractor prior to starting construction, but also insist that these practices be followed.
Construction Resources for Cold Climates
- Trainings: Maine Indoor Air Quality Council’s Residential Construction Trainings (Winter 2019 Series TBA): maineindoorair.org/residential-construction-trainings
- “Builder’s Guide to Cold Climates” – by Joseph Lstiburek. Available on Amazon and other booksellers.
- ASTM E1465 Radon Standard for New Construction – PDF copies available for purchase. https://www.astm.org/Standards/E1465.htm
- Free Publications:
- For New Construction: S. EPA’s Indoor Air Plus Program: https://www.epa.gov/indoorairplus/indoor-airplus-program-documents
- For Renovations, Energy Upgrades: U.S. Department of Energy Builder’s Challenge Guide to 40% Whole-House Energy Savings in the Cold and Very Cold Climates: https://www1.eere.energy.gov/buildings/publications/pdfs/building_america/cold_climate_guide_40percent.pdf
Goals for Your New Home
You want a new home that is:
- Dry (liquid water and moisture/vapor management)
- Pollutant and Pest-Free
- Ventilated with Balanced Mechanical Ventilation
Tip #1: Site Work – Drainage, drainage, drainage
The building and site must provide effective drainage measures to control both surface water and sub-grade water to prevent it from entering the building. If the site is difficult to drain, don’t build a basement.
Tip #2: Install Radon Preventive Features
Radon is a colorless, odorless gas that comes up through the ground and gets trapped in buildings. Radon is the #1 cause of lung cancer in nonsmokers. 1/3 of Maine homes (1/2 in Cumberland County) have a radon problem. Installing radon preventive features at the point of new construction is not only cheaper, it is more likely to be effective without the need for an electric fan.
Tip #3: Waterproof Foundation Walls
Waterproofing, not dampproofing, bridges the cracks that will form in your concrete foundation.
Tip #4: Insulate the ENTIRE Foundation – A “koozie” for your basement.
Insulate under the slab AND all the way up all foundation walls. Best done at the point of new construction outside the foundation walls, but can be done from the inside later.
Tip #5: Install a Moisture barrier under the slab.
This can be part of your radon preventive features.
Tip #6: Install Sill Seal
Create a thermal and moisture barrier between the concrete foundation and the structure of the home.
Tip #7: Cellar Windows are for Light Only, Not Ventilation
Ventilating the basement in the summer in Maine just leads to condensation issues – don’t do it.
Tip #8: Dehumidify
Even well-built, properly drained, and fully-insulated foundations may have moisture problems in Maine during the summer months. Be prepared to dehumidify your basement with a good quality, professional-grade dehumidifier.
Tip #9: Protect Your Building Materials From the Weather
Send back or throw out any moldy materials.
Tip #10: Avoid Traditional Single-Stud Walls with Fiberglass Insulation
This style of framing allows thermal bypass through the wood studs. Newer, better options are available.
Tip #11: Caulk, caulk, caulk
Account for high grade caulking in the budget (a case or more to do it right). Air sealing should be part of your housing budget, not an incidental. Sealing all cracks is critical for both indoor air quality and energy efficiency.
Tip #12: Plan for Ductwork BEFORE You Start Framing. Think Ahead!
Leave space to keep the ductwork inside the heated envelope, not in attic space.
Tip #13: Pay Careful Attention to the Make-Up of the “Sandwich” of Your Walls & Roof.
This is extremely important. The sandwich should keep liquid water and water vapor out, but also provide it with a pathway to get out if (when) it finds its way in. This can be very technical and complicated, and is a bigger topic than can be adequately addressed in this tip sheet. Resources and trainings are available.
Tip #14: Avoid Plumbing in Exterior Walls – Not Even Sewer Drainage.
Condensation issues and frozen pipes are expensive to repair after the fact.
Tip #15: Flashing, Flashing, Flashing
Spend whatever is necessary to properly flash all windows, doors, eaves, valleys, decks, chimneys, plumbing stacks, exterior lights, and other penetrations or areas that alter the natural drainage plane.
Tip #16: Rain Screen/Drainage Plane
An air gap behind the cladding is an excellent idea. Cladding is for looks, not moisture management. A good storm will bypass the clapboards/siding no matter what it’s made of. Give the water a way to get out.
Tip #17: Manage Insulation Cost: Doubling Your R-Value Will Not Halve Your Operational Costs
It is more important for the insulation to be continuous (no gaps or holes) than for it to be thick.
Tip #18: Install Fully Ducted, Balanced Ventilation
The purpose of your new home is to put people in it, and people need ventilation. Fully ducted, balanced systems deliver fresh air to all areas of your home, exhaust pollutants from all areas of the home, and are more energy-efficient than passive ventilation or exhaust-only ventilation. Your goal: Build Tight, Ventilate Right!
Tip #19: Use Sealed Combustion Heating Appliances or Consider Heat Pump and/or Solar Strategies
Heat pump technology has come a long way, and works consistently down to -25◦F
Tip #20: Finishing Smartly
Use low VOC paint. Solid wood details preferred over products with lots of glues. Allow new materials to off-gas prior to occupancy. Don’t install carpet in any area likely to get wet. Place foundation plantings at least 24” from the home, and away from any exterior vents. Keep earth sloping away from the home, and no closer than 8” from any wood surface.
If you have questions about indoor air quality or energy efficiency when building a new home, please do not hesitate to reach out to the Maine Indoor Air Quality Council. We will try to connect you with an experienced and/or certified builder who can answer your questions. We can be reached at 207-626-8115 or by e-mail to: firstname.lastname@example.org.