On the windows that McAlister Construction installs, the average  U Factor is .32, which is the insulation value. When you put insulation in the walls of a home, it has an R value. The higher the number, the better the insulation. R-13 is a typical batt insulation for a 2×4 wall.

The U Factor is the inverse of the R value. So, our .32 U Factor windows are the equivalent of an R-3 in wall insulation. Windows made 20 years ago might have had a U Factor of .75, which means the R Value would have been 1.3333. In other words, the windows that we install today have almost three times the insulation value of those 20 years ago. This isn’t necessarily the case for all builders, but you can rest assured that this type of window is in all of McAlister Construction’s homes.

The second rating is the Solar Heat Gain Coefficient. This number measures the amount of heat that is transferred through the glass. The optimal number depends on what climate you are in. In Oklahoma where it is hot in the summer, we want a low rating which means less heat is transferred through the glass. The rating of a window that McAlister Construction installs is .27. That means that 27 percent of  heat is getting into the house while 73 percent is being blocked. If you lived in Colorado, you would want this number to be the opposite.

Any window with a rating below .3 is great for Oklahoma, and McAlister Construction installs these windows in all our homes. Again, not all builders spend the time or resources to ensure your home is well-insulated, so in other homes, you may find windows without Low-E glazing which have a .6 or .7 rating. This allows a lot more heat through the glass.

Next time you gaze out of your window, remember that it can contribute to insulating your home in addition to your walls and ceiling. If you are in a McAlister Construction-built home, you can know that your windows are assisting you in conserving energy and reducing your utility bills.

We aren’t going to focus on the brand or rating of particular equipment, but instead, we want to talk about proper installation. You can always upgrade the equipment to a higher SEER or efficiency, but your dollars can be better spent simply by installing the system with energy efficiency in mind. This is one area where construction codes don’t do much to protect the homeowner. The minimum HVAC code that many municipalities enforce is not nearly enough to keep your utility bills low and prevent energy loss.

Here is a sealed duct with all seams covered with mastic.

Let’s start with the duct work. This is what distributes the air throughout the house. In a typical new house today, the duct work is wrapped in R-6 insulation and is located in the attic where temperatures can reach more than 150 degrees in the summer. It’s estimated that about 20 percent of the air that moves through the ducts in a typical home is lost due to holes, leaks and improper installation.

Another sealed duct. Notice the R-8 label on the duct.

Unlike many builders, McAlister Construction prevents these potential losses by wrapping our ducts in R-8 insulation and sealing the ducts with mastic at all connection points. This makes them air-tight. And our ductwork is, in fact, air-tight. Each of our houses is tested and our leakage is less than two percent, which is much lower than the average home’s twenty percent loss.

In addition, we install LP TechShield, which is a radiant barrier (roof sheathing product) that offers a variety of benefits including:

* Potentially reducing the tonnage of the HVAC system

* Cutting monthly air conditioning bills up to 17 percent

Studies have shown that this radiant barrier can reduce your attic temperature by 40 degrees on hot summer days.
The next area of focus should be the proper sizing of the HVAC system. Choosing the right size of equipment is essential to achieving the highest performance and comfort. A common myth is that the bigger the equipment, the better the performance. This notion often leads builders to oversize the HVAC system, which results in frequent on/off cycling. This puts stress on the equipment and shortens its life as well as increasing utility bills. To avoid this, every one of our homes is evaluated by both our HVAC contractor and a local energy consultant to determine the proper sizing through the home’s heat loss/gain calculations.

View from below of all the ducts tying into the system.

Touchscreen programmable thermostat

Another detail we focus on in every one of our homes is the installation of a programmable thermostat. This allows you to adjust your home’s temperature by your schedule. For example, during the winter months, if no one is at your home from 8 a.m. until 5 p.m., you can set the programmable thermostat to cycle down to 64 degrees during the hours you are gone and automatically return to 70 degrees when you are home. A properly-used programmable thermostat can save you another 10 percent on utility bills throughout the year.

Just imagine how much more efficient an HVAC system can be when it is properly-sized, controlled by a programmable thermostat, and composed of R-8 sealed duct work in air that is 40 degrees cooler than in attics of other homes. All of these things add up to save our buyers money.

See what a big difference these decisions can make when purchasing a new home? It is so important to make the right decision the first time.

The answer, unequivocally, is yes. The perimeter of the slab is where much energy loss occurs, especially in the winter when temperatures are lower. Uninsulated slabs lose heat through the ground, resulting in higher heating costs for homeowners. Concrete is not an insulator, so when the frame of your wall meets the concrete, the insulation ends.

One of our homes under construction with the insulation shown.

Outside, there is another 2-12 inches of your foundation that typically is exposed to the elements without being insulated. By insulating the exterior edges of the slab, it is estimated that heating bills will drop approximately 15 percent. This is one of the most cost-effective ways to save energy.

Another result of an insulated slab is the relative humidity is typically lower than that of a non-insulated slab. This makes an insulated slab less likely to have the risks associated with mold, mildew, fungal growth, and dust mites.

A slab without insulation along the perimeter will result in heat loss no matter how tightly the rest of the house is built. It is important to take the “whole-house approach” when building an energy efficient home. If you are thinking of building a home, consider McAlister Construction. Though most builders do not prioritize energy efficiency, it is one of the central tenants of our building philosophy. We insulate the slab on every home we build because it will save our homeowners money. It’s not only the smart thing to do, it’s the right thing to do.

That’s why McAlister Construction builds every one of our homes to a higher, more demanding standard that will ultimately reduce our clients’ energy usage and utility bills. This allows our clients to contribute to the important effort to reduce energy consumption while also saving them money. Lots of money. Our buyers find that their utility bills are approximately 50 percent less than those of homes built by other builders. 

The exterior of a home that the "envelope" has been sealed.

So what exactly does it mean to build to a higher, more demanding standard? First of all, it means every single one of our houses exceeds the Energy Star label. To earn the Energy Star, a home must meet strict guidelines for energy efficiency set by the U.S. Environmental Protection Agency. We go above and beyond these guidelines.

"Blown-in blanket" application

It also means that everything we do is inspected by an independent energy inspector both during construction as well as after completion. Before insulation is installed, our homes are inspected to ensure that the envelope, or shell, of the house is airtight. A thorough inspection of the sealed duct work in the HVAC system is also done at this point. After passing this inspection, the home is then insulated, which is followed by another inspection to ensure proper installation before sheetrock is installed.

Many more steps are required in building an energy efficient home, but these early steps are vital to the efficiency of the home. McAlister Construction continues to do it right the first time. 

Sealed R-8 ductwork

Look for upcoming posts where we further dissect and discuss the elements of energy efficient building.