Understanding Energy Efficiency in New Construction

When you’re building or buying a home, some of the biggest decisions are the ones you never see: how the house heats water, how it heats and cools, and how well it keeps the Texas heat out. Builders in North Texas offer more choices than ever, and each one affects your monthly bills and your comfort.

Over my career, I’ve represented both buyers and builders in new construction, and here’s some of what I’ve learned along the way.

Water heaters

Most North Texas homes have one of two setups.

Gas tank: The traditional choice, a large tank that keeps water hot around the clock. It costs less upfront, it’s simple to repair, and plumbers work on them every day. A model with a standing pilot light can still make hot water when the power goes out. The downside is that it heats water all day whether you use it or not, you can run out when several people shower back to back, and tanks usually need replacing sooner than tankless units.

Gas tankless: Now the popular choice in a lot of new construction around the Metroplex. It heats water only when you turn on the tap, so you don’t run out, and it uses less energy. The U.S. Department of Energy estimates tankless units can be roughly 24 to 34 percent more efficient for homes that use a moderate amount of hot water. They take up little space and tend to last longer. On the other hand, they cost more upfront, they need electricity to run (something many of us learned during the February 2021 winter storm), and our hard water means the unit should be flushed regularly to keep mineral buildup from shortening its life.

In homes without gas service, you’ll usually find an electric tank. It’s inexpensive and simple, but electricity generally costs more than gas to heat water, so monthly costs run higher.

Heating and cooling

In a Texas summer, the air conditioner does the heavy lifting no matter how the house is heated, so its efficiency matters most.

Air conditioner with a gas furnace: The classic setup and still the most common. Every HVAC company in town knows it, and gas heat keeps up easily on the coldest nights. The tradeoff is maintaining two separate systems and paying a gas bill in winter. And while you might expect a gas furnace to keep running when the power goes out, it won’t. The blower, ignition and controls all need electricity.

Heat pump: Showing up more often, especially in all-electric homes. It’s an air conditioner that can also run in reverse to heat the house, and it’s very efficient in mild winters like ours. On the coldest nights it leans on backup electric heat, which is expensive to run, and the air from the vents can feel less hot than gas heat.

Smart thermostat: Many builders now include one. It lets you adjust the temperature from your phone and set a schedule, so you aren’t cooling an empty house all afternoon.

Walls and insulation

Before you compare air conditioners, look at what keeps the heat out in the first place. Good insulation lets a smaller system do the job and keeps rooms more even.

Wall framing: Most homes here are framed with 2x4 studs. A few builders offer 2x6 framing on exterior walls, which makes the walls thicker and leaves about 50 percent more room for insulation. That means better protection from summer heat and a quieter house. It costs more, so if a builder offers it, ask whether it covers every exterior wall and what insulation goes inside.

Fiberglass batts: The rolls you see between wall studs, used in most homes. They’re inexpensive, but gaps and compressed spots let heat through, so installation quality matters.

Blown-in attic insulation: Loose fiberglass or cellulose blown across the attic floor. It’s the norm in North Texas attics, covers odd spaces well, and is easy to add to later. It can settle over time and gets disturbed when someone works in the attic.

Radiant barrier: A reflective layer, usually built into the roof decking, that bounces the sun’s heat back out of the attic. It’s standard in most new construction here and well suited to our summers.

Spray foam: Found in some higher-end homes. It seals air leaks and keeps the attic much cooler, which helps the ductwork and equipment up there. It costs more, and it isn’t something you can simply add to a house without other adjustments, since a home sealed this tightly usually needs fresh-air ventilation planned into the air conditioning system. If the foam covers plumbing or electrical lines, repairs can be very difficult. It can also make roof leaks harder to spot, so ask how the roof and attic will be inspected later.

Windows

Windows are often the weakest spot in a home’s energy shell, especially on the west side in August.

Double-pane, low-E vinyl windows: The standard in new construction here. The thin coating on the glass blocks much of the sun’s heat while still letting light in, and vinyl frames insulate well. If a seal fails, the glass can fog between the panes, so ask about the warranty.

Older homes: Many have single-pane glass or aluminum frames, which let in much more heat. Replacement windows are one of the more noticeable upgrades in an older house.

Builder energy scores

Many DFW builders advertise an energy score for their homes, and a lower number means a more efficient house. If you see one in a brochure, ask how it was measured and how it compares to the builder’s other plans.

Less common options

You’ll occasionally run across these, but they’re the exception in North Texas.

Heat pump water heater: The efficient electric choice. It pulls heat from the surrounding air, works well in a garage, and costs much less to run than a standard electric tank. It costs more upfront and needs room and airflow.

Electric tankless water heater: Fine for a single far-away sink, but heating a whole house this way takes a lot of electrical capacity and can struggle with more than one shower running.

Solar water heating: Roof collectors warm water before it reaches a backup heater. It’s rare here, so experienced installers and repair people can be hard to find.

Geothermal: Loops buried in the ground heat and cool the house very efficiently and quietly. The upfront cost is high, not every lot has room, and fewer local contractors service it.

Solar panels: They can noticeably lower an electric bill, but the savings depend heavily on your electricity plan, since what providers pay for extra power varies widely in Texas. Most systems shut off during an outage unless paired with a battery, and hail can damage them. If panels are leased or financed rather than owned, that agreement has to be dealt with when the home is sold.

Triple-pane windows: Quieter and better insulated, but they cost more and offer less benefit in our climate, where blocking sun matters more than holding heat in.

A note on tax credits

If someone tells you a federal tax credit will cover part of the cost, double-check. The federal Residential Clean Energy Credit, which covered solar panels, battery storage, geothermal and solar water heating, ended for systems installed after December 31, 2025. The federal credit for heat pumps and heat pump water heaters ended at the same time. Utility, city or manufacturer rebates may still be available, so ask your providers directly and check the program’s own website.

How to check for yourself

• Ask the builder for the specifications in writing: water heater and HVAC make and model, wall framing, insulation and windows. Look up warranties and maintenance requirements on the manufacturer’s website.
• Look at the insulation yourself during the pre-drywall walkthrough, before it’s covered up.
• Check the yellow EnergyGuide label on appliances to compare estimated yearly operating costs.
• Use the government’s own guides at Energy.gov and EnergyStar.gov.
• Check the IRS website for the current status of any tax credit before counting on it.
• If a home has solar panels, ask for the paperwork showing whether they’re owned, financed or leased.

From what I’ve seen, spray foam does a great job of making a house quiet and energy efficient, but it can turn a simple repair or a roof leak into a bigger project. I’ve also seen homeowners get into trouble by sealing the attic too tightly without adjusting the air conditioning system to match. And owners who put in an electric tankless water heater for the whole house have often been unhappy with how high their electric bills ran.

If you’re interested in property in the DFW area, I’m happy to help.