If you request energy-efficient construction, your builder will mostly focus on the building envelope. This system involves the whole outer shell of your home, including the walls, roof, windows, doors, and foundation. They seal and insulate all these parts, keeping the warm or cool air inside your home and stopping it from leaking out.
As per ENERGY STAR reports, ENERGY STAR-certified buildings use 35% less energy compared to normal buildings nationwide. You'll notice that the gap comes down to how well your builder seals the envelope.
When you own a home, having a tighter envelope means getting less costly utility bills and fewer drafty rooms. Since energy standards are getting stricter, your home also gets to meet code.
Whether you're comparing floor plans with a builder or evaluating quotes from different energy performance contractors, you should pay a lot of attention to your envelope. It'll save you a lot of energy and money.
What Is a Building Envelope?
A building envelope is the part that creates a physical barrier between the interior and exterior areas of your home. It includes:
- The roof
- Exterior walls
- Flooring systems of a building
For your building envelope to work, each of these parts has to hold its own insulation value and connect cleanly to the next one.
Why Are Home Builders Strict on Building Envelopes?
A lot of homeowners want energy-efficient new home construction. As a result, home builders have to ensure newly built homes fit these standards. Here are the reasons why your contractor may be too keen on the building envelope:
Building Codes Keep Raising the Bar
Since 2015, the International Energy Conservation Code requires blower door testing on new homes. During this test, they place a large fan in the doorway to suck air out and measure how leaky the house is.
The result is given as a number called ACH50. In most climate zones, that number must be 3.0 or lower to pass. If your house scores higher than 3.0 ACH50, your home builder must find and seal all the leaks and test again until it passes.
Before this rule, many homes were built with looser construction and still met the old building codes. However, builders right now have to prove their homes are airtight enough before the city will approve them.
Buyers Want Energy-Efficiency
Homebuyers touring newly built homes are keen on energy efficiency. They'll ask builders about utility estimates and envelope performance. As a result, builders are choosing efficiency to make their clients happy.
Material and Energy Costs Reward Building Tight the First Time
It's cheaper for you to build the envelope right during construction. Sealing and insulating locks in performance before drywall goes up. You'll save money on materials and energy.
What Materials Will Make Your Home Airtight?
If you want to have tighter envelopes, you need continuous insulation and proper air sealing at every seam. Here are materials that can help you achieve this:
Spray Foam Insulation for Your Home
If you want to fill irregular gaps that batt insulation can't, spray foam insulation for your home works well. The foam expands into rim joists, stud cavities, and odd framing angles to create both insulation and an air barrier at once.
Continuous Insulation
Traditional framing loses a lot of its insulating value through the studs themselves, leading to thermal bridging. To solve this, your builder will insist on wrapping the exterior in a layer of continuous rigid foam or mineral wool to break that path.
Air Barriers That Seal Every Seam
Insulation alone doesn't stop air movement. If you want to stop air movement, you need a dedicated air barrier. Apart from your insulation layer, use taped sheathing seams, fluid-applied membranes, and sealed penetrations.
How Do You Choose the Right Energy Performance Contractor?
When working on a new construction, you need the right builder. Here is what you can do to get the right contractor:
Ask About Their Usual Blower Door Results
Any home contractor can tell you the code minimum. However, you need to ask instead what their homes usually score. If the builder regularly passes the test, they're the right energy-efficient contractor to partner with.
Request Line-Item Insulation Detail
Make sure your contractor gives you the R-value and insulation type spelled out for walls, roof, and foundation individually. Avoid builders with vague specs.
Confirm How They Verify and Ventilate a Sealed Home
Ask the builder you would like to partner with to check that the air barrier is continuous before drywall goes up. You should also find out how they handle mechanical ventilation once the home is sealed tightly. Make sure you have references from recent newly built homes, so you're evaluating their current standards.
Frequently Asked Questions
Where Does Your Home Leak the Most?
Air rarely escapes evenly across your house. It concentrates at specific weak points. Here are some areas where your energy performance contractors will check:
- Poorly sealed window and door frames
- Gaps around plumbing, duct, and utility penetrations
- Rim joists where your foundation meets the framed floor
- Attic penetrations around vents, wiring, and recessed lighting
- Wood studs and other framing that conduct heat around the insulation
These gaps are usually hard to notice. If you want to enjoy comfort and affordable monthly bills, you should consider sealing them.
Do Airtight Homes Need Mechanical Ventilation to Stay Healthy?
Yes, once your home is sealed tightly, it no longer needs incidental leaks for fresh air. For this reason, builders will often add a mechanical ventilation system. It helps you bring in fresh outdoor air into your space on a controlled schedule.
Are There Tax Credits for Building an Energy Efficient New Home?
If your new home is certified to ENERGY STAR or Department of Energy Zero Energy Ready Home standards, the federal 45L tax credit offers builders and developers up to $5,000 per home. Make sure you ask your builder directly if they're pursuing this certification. It can influence both your home's price and its long-term efficiency.
Invest in Energy-Efficient Construction for Cost Savings
Your energy-efficient construction starts with focusing on a tight, well-insulated envelope. Make sure you find a home builder that understands this to get value for your money.
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This article was prepared by an independent contributor and helps us continue to deliver quality news and information.
