Attic hatches and attic pull-down stairs can be a huge source of heat loss. They are often not air sealed, allowing air to transfer between the conditioned space and the attic, and they are often constructed from thin wood or drywall, which does not prevent heat loss effectively. Build an air-tight, well insulated attic hatch by weather-stripping around the edges to create a tight seal, and attaching at least 6 inches of rigid insulation to the hatch panel.

Basements or crawlspaces are often the second largest area of heat loss in your home (after the attic). Some of the leakiest parts of the basement are the box sills, sill plates, and rim joists. The sill plates and rim joists sit on the foundation wall. Air leaks through the gaps and cracks all the way along your foundation wall. Your rim joist or box sills may already be insulated with fiberglass; however, fiberglass does not stop air leaks effectively.

A bulkhead door is one of the leakiest parts of a basement, and in many cases, is built from a simple piece of plywood that doesn’t close tightly. Install weather stripping around the edges and insulate the door with at least 1.5 inches of rigid insulation. Alternatively, you can replace it with a new well-insulated exterior door.

Attics are often the single largest source of heat loss in a home, due to both air leakage through gaps and holes, and lack of sufficient insulation.

Sealing air leaks with a professional spray foam gun is highly effective. Once air leaks have been sealed (common ones include openings made for plumbing and electrical lines), then additional insulation can be added. If you heat or cool your home with forced air, you could be losing heat through your ducts – seal the ductwork and any uninsulated crawlspaces.

According to the U.S. Department of Energy, leaky windows can account for 10–25% of your heating bill. If your windows are in fair shape—or if you’re on a tight budget—adding storm windows is far more affordable than replacing the whole window. Storm windows keep outside air from seeping in and protect your windows and doors from storm damage. They are most often installed on the exterior of your existing windows, but you can opt for interior storm windows as well.

To prevent drafts from windows, start by fixing some common sources of air leaks: add caulking around window casings, fill in unused pulley cavities, and replace cracked panes and glazing compound (be careful not to caulk the window shut). Then add weather-stripping around the edges.

Exterior doors in your home can allow air leaks even when they are closed. Use clear acrylic caulk to seal air that is leaking around the frame of the door, and install a door sweep at the bottom to prevent strong drafts. Then weather strip the door to create a tight seal.

This is a common problem area in stone foundations. Seal air leaks with a professional spray foam gun. You’ll stay more comfortable, year-round.

If you heat or cool your home with forced air, you could lose up to 30% of it through your ducts – if they’re in a cold space and not sealed. That leads to uncomfortable rooms and high energy costs. Sealing them up can make a big difference. You can get duct sealant at your local hardware store.

Insulating the hot water pipes with foam tubes helps keep water hot as it travels from your heater to where you’re using it. Pipe insulation is cheap and easy to add. Some newer water heaters have built in insulation. If your water heater says it has less than an R25 insulation, or if it feels warm when you touch it, it’s worth insulating. Figure out the size of your pipes (likely ½ or ¾ inch) and pick up some insulation and duct tape at your local hardware store.