Where Does Your Home Lose The Most Heat?

Mutual Assurance Society
Jan 31, 2023
4 min read

We have an infographic that shows you where your home is letting in the most cold air and how you can address the leaks.

Gaps 38%

They may seem small, but those gaps around your internet cables, your pipes, and your chimney are the number one cause of heat loss in most homes. Here's how to address them:

Depending on the size of the gap, exterior-grade caulking will address most issues. Be sure to use a brush to remove any dirt or debris around a pipe or cable, then caulk, wiping away any excess.
If the gap is larger, you may want to use waterproof spray foam. You can fill the space and then use a painter's tool to smooth it out.

Basements 21%

Air leaks in a basement are more common than you might think. In addition to the edges of doors and windows, rim joists, seams and joins between the floor, walls, and ceiling can all generate air leaks which will lose heat. What’s more, existing sealant can degrade over time, more than concrete, brick or tempered or pressure-treated wood.

In order to eliminate heat being lost, you first need to be able to locate the cold spots in your basement, where the most heat loss is occurring. A thermal camera is the best way to scan a room or space for temperature variations. Some Home Depots will rent a camera, or you can find a heating specialist to do a survey for you. Or if you are a DIYer, there is a device called Flir One that attaches to your phone or tablet and gives you thermal images of your space, and a hand-held device called Perfect Prime that works on its own.

Once you have identified the cold spots in your basement, you can check the insulation, caulking, and gaps.

Walls 17%

The main reason your walls feel cold is a lack of insulation. Heat loss through walls can be reduced with cavity wall insulation. A contractor blows insulating material into the gap between the brick/siding and the inside wall.

Insulating materials are bad conductors, so this reduces heat loss by conduction. The material also prevents air from circulating inside the cavity, reducing heat loss by convection.

Windows 16%

We've all seen a commercial that shows someone holding a candle next to a window edge and watching the cold air nearly snuff it out. There are many options on the market today that can help insulate your windows effectively.

The first thing to do, however, is check the caulking around your windows. This is the simplest and fastest way to address leaks and will save you down the road as water will not leak behind the windows and cause rot as well.

Other options include storm windows, window films, and even interior storm windows or storm window inserts.

These vary in design. Some are constructed from sheets of light, strong acrylic or Plexiglas, edged with compression tubing. Other designs feature glass with low-emissivity (low-e) coatings, which improve energy efficiency.

The storm window inserts are pressed into place inside the window frame, sealing it against drafts. Some designs install without the use of nails, screws, or adhesives. Others may require the installation of a double or triple track to hold the insert in place.

Their advantage is they are unobtrusive and easy to store when not needed, so you can open your windows for some fresh air once the temperatures rise outside.

Ceilings & Roofs 5%

While hot air rises, by the time it reaches your attic, it has probably cooled significantly. The falling cooler air is actually a greater worry.

It is always a good idea to make sure your attic door or fold-down stairs opening is secured to prevent as much cold air from cascading into your home as possible.

Insulation will help. Attics in Virginia should have an R-38 insulation level. R-values are used by the construction industry to describe the thermal resistance of insulation materials, like those used to insulate your attic. When you are looking at an R-38 insulation, you are actually reading a description of its resistance, rather than size or thickness of the material.

The only way to know for sure whether your attic has enough insulation is to schedule an inspection with a licensed insulation contractor. As a general rule of thumb, every inch of insulation provides an average R-Value of 3. So for most homes in Virginia, there should be 11–13 inches of insulation in the attic. a quick way to determine if you need more insulation is to take a look in your attic, and if the insulation is below the floor joist, you probably need more.

It is easy for insulation to get displaced or compacted in your attic, so checking it every 5 years or so, especially if you've had workers up there, is a good idea.

Doors 3%

As doors shrink in cold weather, small gaps can occur.

This is where the candle check can come in handy. Simply light a candle and move it around the edges of your door. If you see it flicker a lot, you may have an air leak.

For leaks at the sides and top, foam weather stripping can be added. At the bottom, a sweeper-style weather stripping and a rubber door sill will help. You should check around door knobs and locks too, in case there is a separation between the units and the door that could let in air. A weatherproof caulk will fix those leaks quickly.

The type of exterior doors you have can also impact your heat loss. Steel doors will get colder and hotter depending on outside temperatures, and that cold can affect the interior temps. Storm doors will help considerably and provide a buffer between the outside and interior temperatures.

What steps do you take to keep your home from losing heat in the winter?