Efficiency: Designed Into the Home

When people hear the words energy-efficient home, they often think first about products: better insulation, more efficient windows, a high-efficiency heat pump, LED lighting, or energy-efficient appliances.All of those things can matter. But none of them, by themselves, make a home efficient.A truly efficient home begins much earlier. It begins with the way the home is designed, how its walls and roof are assembled, how air and moisture are controlled, and how its heating, cooling, and ventilation systems are selected to work with the home rather than fight against it.Efficiency is designed into a home—it is not installed after the fact

A House Doesn't Need to Breathe

One of the most common misconceptions we hear is that “a house needs to breathe.”It doesn't. Breathing is for living things.What a house does need is proper ventilation, and there is an important difference between ventilationand leakage.Ventilation is intentional. Air leakage is not.There is certainly nothing wrong with opening the windows on a beautiful spring or fall day. We hope homeowners do. When you open a window, you have made a decision about when and where you want outside air coming into your home.But when you close that window, the fresh air shouldn't continue coming in around it.The same is true throughout the house. We don't want outside air entering through gaps around doors, electrical penetrations, framing connections, attics, floors, or hundreds of other little openings hidden within the structure.Instead, we want to build the home as tightly as practical and then provide the fresh air its occupants need through a properly designed ventilation plan.That gives us something enormously valuable: control.

Comfort and Efficiency Are Closely Connected

This is also where efficiency connects directly back to another characteristic of a high-performance home: comfort.Uncontrolled air rarely leaks evenly throughout a house. It finds particular pathways. That can contribute to drafts, cold spots, hot spots, and rooms that never seem to be quite as comfortable as therest of the house.But outside air doesn't bring temperature alone. It brings moisture with it.During a hot, humid Georgia summer, every bit of uncontrolled outside air that enters the home brings heat and humidity that the air-conditioning system must remove. During cold weather, incoming outside air has to be heated.

At the same time, air that has already been heated, cooled, and dehumidified may be leaking out somewhere else.The HVAC system is then being asked to continually correct conditions that the house itself is creating.A well-designed and well-sealed building envelope gives the mechanical system a much easier job. Temperature can remain more consistent, humidity can be better controlled, and less energy is required to maintain comfortable conditions.In that sense, comfort and efficiency aren't competing goals. They are often the result of the same good decisions

What Happens Inside the Walls Matters

Some of the most important features of an efficient home will never be seen by the homeowner once the house is complete.Efficiency has to be considered deep in the design stage, including how we control the movement of air,moisture, and heat through the building.That means thinking beyond simply sealing around windows and doors. The walls, ceilings, roof, foundation connections, and penetrations need a thoughtful strategy for controlling air and moisture throughout the entire building envelope.Insulation is an important part of that strategy, but insulation alone doesn't tell the whole story.We also have to consider the pathways that allow heat to travel through or around the insulation. The framing that holds a house together can also conduct heat through the wall. These pathways are called thermal bridges.A properly designed wall system looks for ways to reduce or interrupt those bridges so that heat has a harder time moving in the wrong direction—out of the house in winter and into the house during summer.The important number, therefore, isn't simply the R-value printed on a package of insulation. What matters is how the entire wall system performs once all of its components are put together.

Bigger HVAC Equipment Isn't Better

Another common misconception is that bigger heating and air-conditioning equipment must be better.If a certain size air conditioner will cool the house, it seems logical that a larger one would cool it even better.Unfortunately, that's not how it works.An oversized air conditioner may bring the temperature down very quickly. But cooling the air is only part of its job—especially in our humid climate. The system also needs enough operating time to remove moisture from the air.If an oversized system satisfies the thermostat too quickly and shuts off, the temperature may be right while the humidity isn't. The result can be a house that feels cold and clammy rather than comfortably cool.That's why HVAC equipment should be calculated, not guessed.

The correct equipment size depends on much more than the square footage of the house. Windows, insulation, air leakage, ceiling heights, orientation, exterior wall area, local climate, and numerous other characteristics affect how much heating and cooling a particular home actually needs.A professional load calculation can account for those factors and help determine the appropriate equipment for that particular home.When it comes to HVAC systems, more is not necessarily better, and bigger is not necessarily better. Right is better.

The House and the Equipment Should Work Together

This brings us to a larger point.A heating and cooling system shouldn't have to overpower the house in order to make it comfortable.If we reduce unwanted air leakage, properly insulate the building envelope, limit unnecessary heat transfer, control moisture, provide intentional ventilation, and then correctly calculate the home's heating and cooling needs, something important happens:The HVAC system no longer has to fight the house.Instead, the building and its mechanical systems begin working together.That is the difference between looking at efficiency as a collection of products and looking at the home as a complete system.

Eliminating Drafts and Pressure Imbalances

A truly high-performance home does not happen by accident, and it doesn't happen simply because a builder uses good materials.It starts with good planning.When high performance is an important goal, we believe the design process should include someone with specific expertise in how a home will perform—not just how it will look or how it will be constructed. That expertise can help the builder and the rest of the design team make decisions about the building envelope, ventilation, insulation, moisture management, and mechanical systems before construction makes those decisions difficult or expensive to change.There is an additional cost to doing that work on the front end. We believe it is money well spent.It is less expensive to determine how a wall should be built before it is built. It is easier to plan proper ventilation before the walls are closed. And it makes far more sense to calculate how much heating and cooling a home actually needs before the equipment is purchased.The consequences of those decisions can remain with the homeowner for decades—in utility bills, comfort, equipment life, humidity control, and the durability of the home itself.We would rather invest a little more time and money thinking about the house before we build it than spend considerably more trying to fix the house after we build it.

Efficiency Is More Than an Energy Bill

Of course, an efficient home should cost less to heat and cool. But if we stop there, we miss much of the benefit.The same decisions that reduce energy consumption can create more even temperatures throughout the house. They can improve humidity control. They can reduce drafts. They can allow mechanical equipment to operate the way it was designed to operate. They can even contribute to the durability andhealth of the home—two other characteristics of high-performance construction that we will explore in this series.That is why we don't view efficiency as an upgrade package.It is a way of thinking about the entire home.A high-performance home doesn't need to be filled with exotic technology or the most expensive products available. Often, its greatest advantages come from ordinary materials that were selected carefully, assembled correctly, and designed to work together.The best time to make those decisions is not after the homeowner receives the first utility bill. It isn't after a room feels uncomfortable or a humidity problem appears.The best time is before construction begins.Efficiency is designed into a home—it is not installed after the fact.

At Cutler Structures, we believe a home should be more than attractive finishes and impressive curb appeal.

A truly exceptional home is one that is comfortable, durable, efficient, healthy, and resilient. These principles guide the decisions we make throughout the design and construction process because we believe homeowners deserve a house that performs as beautifully as it looks.

That is what we mean when we talk about a high-performance home.