Built to Code vs. Above Code: What "Energy Efficient" Should Mean in a Bid

"Built to code" sounds like a standard of quality. It isn't. Building code is the minimum a house can legally be built to in your jurisdiction. A house built exactly to code is the least house the building department will sign off on.

That's not a knock on code houses. Code minimums are real, they're enforced, and plenty of good homes are built to them. But when a builder or a brochure says "energy efficient" or "built above code," that should mean something specific you can point to. Often it doesn't.

Why "energy efficient" isn't a spec

Every house built to a current energy code is energy efficient compared to one built thirty years ago. So the phrase on its own tells you almost nothing. What you want to know is how the house compares to the code it's being built under, in numbers, and how anyone will know the numbers were met.

Start by finding out which code applies. Jurisdictions adopt different editions of the model codes, and some add their own requirements on top. Your architect or the building department can tell you what your house is being permitted under. That's the baseline. "Above code" only means something measured against it.

What above code should be backed by

Insulation, by assembly. R-values for the walls, the roof or ceiling, the foundation walls, and the slab edge, stated for each. "R-21 walls" is a spec. "Upgraded insulation" isn't.

Air tightness, with a test. How leaky a house is gets measured with a blower door test, and the result is reported as air changes per hour at a set pressure. If your jurisdiction is on a recent energy code, the house may need this test anyway. The question is what target the builder is aiming for, whether it's tighter than code requires, and whether you get the test result in writing.

Windows. U-factor and solar heat gain coefficient, from the window label or the quote. In the mountains, windows are a lot of wall, and the difference between window packages is real.

Heating, cooling, and ventilation. The equipment and its efficiency rating, and how fresh air gets into a tight house. A tight house needs mechanical ventilation, usually an ERV or HRV. If a bid promises a tight house and doesn't mention ventilation, ask.

An outside rating, if you want one. A HERS rating or a third-party program gives you a number someone other than the builder checked. Not every house needs one, but if energy performance matters to you, it's the cleanest way to know you got what you paid for.

It isn't only energy

The same gap shows up in other places code sets a floor. Roofing underlayment and ice barrier beyond the eaves. A rainscreen gap behind the siding. Sound insulation between bedrooms. Radon mitigation, where code may require only a passive system or nothing at all. None of these is required to be above code, and any of them may matter to you. If they do, they belong in the finish brief and the bid, written out.

Getting it into the bid

If you want a house that performs above code, decide what that means before bidding and put it in writing: target R-values, an air tightness target with a test, window performance, ventilation. Send it to every builder with the drawings. Then you're comparing bids for the same house, and "energy efficient" turns into specs you can check against the plans and the finished building.

It's also worth asking a builder's past clients about it. Not "is the house efficient," but how it holds heat on a cold night, whether some rooms run colder than others, and whether the ventilation system works the way they were told it would.

Questions worth asking:

• What energy code is this house being permitted under?
• Where exactly is this house above that code, in numbers?
• What R-values are in each assembly?
• What air tightness target are you building to, and will I get the blower door result?
• What are the U-factor and SHGC of the windows you priced?
• How is the house ventilated?