Building for Energy Efficiency

At Lally Construction & Design, both the design and construction are engineered in such a way to maximize energy efficiency.

Any detail, whether big or small, can make substantial differences in one’s energy bills and the comfort of the home. Achieving a tight building envelope during construction pays dividends for the life of the home, as the cost of energy is only going in one direction, which is up.


When building a multiple story house, we strive to put most, if not all of your ductwork for the upper story in the floor system. It can be quite a bit more work, but it means any temperature convection from that ductwork goes right back into your house.

Most builders put the air handler equipment and the ductwork in the attic for the second floor, as it is MUCH easier to do that, but it also means your heating and cooling your attic BEFORE you are heating and cooling your house.

Having the equipment and ductwork in the extreme temperatures of an attic also leads to a much faster degradation of your ductwork.

Crawl Spaces

Whenever possible, we design a sealed/insulated and conditioned crawl space and condition the crawl space with the home’s HVAC system.

While it may seem counter-intuitive for efficiency to blow conditioned air into your crawl space, the science shows that it actually makes your house 15% more efficient; this also has the benefit of keeping your ductwork dry, thus eliminating the spread of mold.

If you’ve ever been inside a conventional vented crawl space on a hot and humid North Carolina day, you would know that the ductwork can sweat considerably with condensation from the warm/humid air contacting the cold ducts. A conditioned crawl space eliminates that problem and also regulates the floor temperature, making it more comfortable for you to walk on, as it is nearly the same temperature as your house.

Foaming Behind Outlets and Switch Boxes

Few builders go to the trouble of foaming behind the outlet and switch boxes adjacent to outside walls, but we do. It costs little if done during construction, and it’s one more detail that we take care of in every house that contributes to a high (low numerically) HERS rating.

Have you ever put your hand in front of an outlet on a cold winter day and felt the cold air wafting through? That problem is solved by foaming the outlets.HERS Energy Rating Certificate for one of our builds

A HERS (Home Energy Rating) is an analysis of a home’s projected energy efficiency compared to the efficiency of a ‘reference home’ that is built to the latest residential energy code.

The lower the number the better. An average existing home in NC will rate in the 130-140 range. A new home built to current code will rate at 100.

This is an example of a house built by Lally Construction & Design in 2020. It rated at an outstanding 47. This house was built using our typical building techniques. This shows you how attention to detail will save our homeowners a great deal of money over the years.

Ceilings and Roofs

We Insulate the ceiling beyond code. Again, it’s inexpensive if done during construction, but pays off fast in our climate.

We also install roof sheathing with a radiant barrier bonded to the underside of the sheets. This is equal to an additional R10 of value in the summertime and makes your roof shingles last longer.


Higher than code windows are used in our construction.

We specify ultra-lowE (or lowE2) windows with argon gas between the panes. The Ultra lowE makes for very little solar gain in the summer and the high density of argon causes less convection heat loss in the winter.

This only adds about 8 dollars per window over a minimum code window, but the payback is large.


We strive to use LED lighting throughout the house whenever possible.

Ready to find out more?

Call Mark now, at 910. 638. 8236. Or, click the button to send your contact information.