Airtightness.jpgMaking a home as airtight as possible is necessary if it's going to be energy efficient. Click here to learn how you can achieve airtightness when constructing.

Ever lived in an old house? They're cold.

That dewy condensation builds up on the inside of the windows, giving older homes their distinct draftiness.

The reason those structures get cold like that is that they aren't airtight, and that's actually costing you a lot of money.

Airtightness not only keeps your house warmer, it can lower your utility bill to only $20 a month.

So how does an airtight house work?

Airtightness Versus Ventilation

Air is constantly escaping from houses.

It sounds weird when we try to imagine air going through walls, but think of it this way.

Our bodies create heat, but the heat doesn't just sit inside of us. It escapes. If we get cold, we put on a jacket that makes it harder for our heat to escape, so we feel warm.

Houses do the same thing. You may not even realize it most of the time, but you probably notice it during the winter.

Your house gets cold!

Warm air escapes and cold air leaks in through the walls. You have to pay money to keep the heaters going for months.

But don't confuse making your house airtight with cutting off all ventilation. A house must be properly ventilated to even pass code so you and your family can stay healthy. An airtight house simply controls the escaping and leaking air, which is called infiltration.

How Is It Possible for Air to Escape and Leak?

The air gets in and out through little holes you don't even notice. It travels through things like nail holes, window frames, and door frames.

An airtight house seals up all those problem places. This makes the house more energy efficient because you don't have to keep the heater going.

How to Make a House Airtight

First, every hole and crack (every single one) must be sealed. Anywhere a nail or screw was used, any place a pipe or cable goes through the wall, or any area there is a corner or a seam, must be covered.

Places like window and door frames can be especially problematic. The glass inside a window must be carefully sealed and a door must not let any air escape when it is closed.

After every hole is sealed, cover everything else, all the walls and corners and ceilings, with weather barrier and thermal insulator.

This sounds fancy, but it is just a building membrane that keeps air from leaking inside or escaping outside. It looks a lot like paper.

Test, Test, Test

Before the house is finished, it must be tested to make sure no air is going where it isn't supposed to go.

One of these types of tests is called the blower door test.

Essentially, you create a seal around the door and suck all the air out of the house. This makes the air pressure drop, and you can go in and check where any high-pressure air is coming back inside.

If you want a really airtight house, you should do this several times before you finish the rest of the house. It is a lot harder to make a house airtight when it is already built.

Airtight Houses Are Energy Efficient (and Warm)!

Airtightness is a strange concept to think about, especially in a house. Just think of it like a house-sized jacket. The air stays where you want it to stay, and it saves you money.

Getting ready to build or remodel your house?

Contact us and we'll make sure you end up with the home you want!

About The Author

Hi, we're the Designblendz team! We blend overlapping design disciplines to raise the standard to design, visualize, and build virtual and physical environments.