Why is my house so cold?

A house feels cold for one of two reasons: heat is escaping, or heat is not reaching you. Often it is both.

Possible causes

• Air leaks (drafts). Gaps around windows, doors, outlets, attic hatches, recessed lights, and where pipes and wires pass through walls and floors. ENERGY STAR says air leaking through the outer walls, windows, doors and other openings is where much heat is lost. ^[1]
• Not enough insulation, especially in the attic and over crawl spaces or basements. ENERGY STAR says that 9 out of 10 US homes are under-insulated. ^[1]
• The heating system is not doing its job. A dirty filter, blocked vents, closed registers, ducts that leak, or an old system. ENERGY STAR says airflow problems can reduce efficiency by up to 15 percent. ^[2]
• Windows. Single-pane or leaky windows make nearby rooms feel cold even when the thermostat says otherwise.
• Uneven heat distribution. Rooms far from the furnace, over garages or at the end of long duct runs.
• Moisture. Damp insulation insulates poorly, and damp air feels colder. See why is my wall damp?

How to identify the cause

Work from free to paid:

1. Check the basics. Is the air filter clean? ENERGY STAR advises inspecting, cleaning or changing filters once a month in central heating and cooling systems. ^[2] Are vents and registers open and unblocked by furniture or rugs?
2. Do a draft walk-through on a cold, windy day. Feel around window and door frames, outlets on outside walls, the attic hatch and the fireplace damper. Moving a lit incense stick or a tissue near gaps shows airflow. (A rule of thumb, not a measurement.)
3. Look in the attic. If you can see the tops of the floor joists, there is probably not much insulation. Compare with the recommended levels for your climate zone on the ENERGY STAR site.
4. Note which rooms are cold and when. Cold only upstairs or only above the garage points at insulation or ducts. Cold everywhere points at the heating system or the whole envelope.
5. Get a home energy assessment if you want it measured. The Department of Energy describes what an assessment involves. ^[3] Add-ons include a blower-door test, which measures how leaky the house is, and thermal imaging.

If it is only upstairs: warm air rises, so heat escapes through the ceiling into the attic and cold air is drawn in low down. Upstairs rooms sit just under the roof, so thin attic insulation, gaps around the attic hatch or ceiling lights, and long duct runs to the second floor are the usual suspects. A single system serving two floors can also be hard to balance. Check the attic first, because it is the cheapest to look at. ^[4]

How serious is it?

• Comfort and moneyDrafts, cold rooms and high bills. Not dangerous, but you are paying for heat that leaves.
• Look into itIce dams on the roof edge in winter, condensation or mold in cold corners, or a heating system that cannot keep up. These can lead to damage.
• Safety firstDo not use an oven, gas range or unvented fuel-burning heater to heat a home. If you have headaches, dizziness or nausea that clear when you leave the building, get fresh air and call emergency services. These can be signs of carbon monoxide.

What can you do?

Roughly in order of cost-effectiveness. Order depends on your house, so treat this as a starting list:

1. Replace the filter and clear vents. Costs almost nothing.
2. Seal obvious leaks. Caulk and weatherstripping around windows and doors; foam gaskets on outlets.
3. Air seal the attic, then insulate it. ENERGY STAR estimates that air sealing and adding insulation can save an average of 15% on heating and cooling costs, or 11% on total energy costs. ^[1] That is an average estimate, and your result depends on the house you start with.
4. Seal and insulate ducts that run through unheated spaces.
5. Get your heating and cooling system serviced once a year; ENERGY STAR recommends an annual tune-up before each season. ^[2]
6. Consider windows last. They are usually expensive for the energy they save. Storm windows or window film can be a lower-cost step.

Typical cost

These are ranges reported by the sources cited, not quotes. “Scope and date” is the geography the source covers and when it was published or last updated. Your price depends on your home, your area and the contractor.

An audit helps most when you plan to spend a few thousand dollars and want to know where it will do the most good. If you only have a drafty door, you probably do not need one.

Does fixing it affect property value?

“Return” is more than resale price. Where we have no reliable figure we say so instead of guessing. See how we think about value.

Comfort upgrades like insulation and air sealing mostly pay back through lower bills and a more comfortable home. We have no reliable published figure for how much they add to resale price. The Cost vs. Value report we use for other projects does not cover them as individual items, so we will not give a percentage. Savings estimates from ENERGY STAR are averages and assume a typical starting point.

Related tools

We do not have a calculator for this yet.

Deeper technical explanation

Heat moves three ways: conduction through materials (insulation slows this), convection by moving air (air sealing slows this), and radiation (windows and attic heat). In winter, the bigger problem in many houses is air movement: warm air escapes through the top of the house and cold air is drawn in low down (the “stack effect”). That is why air sealing the attic often does more than people expect.

Insulation works by trapping still air, so gaps, compression and wet insulation all hurt it. R-value measures resistance to heat flow, and recommended levels depend on the climate zone.

Why a blower-door test helps. It depressurizes the house and shows where the air comes in, so work can be targeted. Thermal imaging shows temperature differences on surfaces but is easier to read in a big temperature difference between inside and outside.

Limits. Climate, house age and heating type change which fixes are best. A house in Phoenix and a house in Minneapolis have different priorities. Cost ranges are national and from cost-guide sites.

Sources & methodology

Savings figures come from ENERGY STAR and are described as estimated averages. Cost ranges are from HomeGuide and are shown as ranges. The draft test above is labelled as a rule of thumb. See how we work out costs.

1. Why Seal and Insulate? — ENERGY STAR (U.S. EPA / DOE) Government agencyEstimated savings from air sealing and insulating, and common signs a home needs it. Accessed October 4, 2026.
2. Heating and Cooling Maintenance Checklist — ENERGY STAR (U.S. EPA / DOE) Government agencyFilter checks and annual tune-ups; effect of airflow problems on efficiency. Accessed October 4, 2026.
3. A Guide to Home Energy Assessments — U.S. Department of Energy Government agencyWhat a home energy assessment involves. Accessed October 4, 2026.
4. Identify Problems You Want to Fix (Seal and Insulate) — ENERGY STAR (U.S. EPA / DOE) Government agencyWarns that sealing a home may trap indoor air pollutants such as radon, carbon monoxide and VOCs; points to DIY checks. Accessed October 4, 2026.
5. Home Energy Audit Cost — HomeGuide Cost guide (crowd/contractor data)Audit, blower-door and thermal-imaging costs. Updated Oct 2024. Scope: US national. Published or updated: Oct 2024. Accessed October 4, 2026.
6. Home Insulation Cost — HomeGuide Cost guide (crowd/contractor data)Insulation and air-sealing costs. Updated Dec 2025. Scope: US national. Published or updated: Dec 2025. Accessed October 4, 2026.