The whole-home energy audit: a room-by-room checklist

KiloWise editorial team · Last updated 5 November 2026 · Category: Bills & Tariffs

A home energy audit is a slow walk around your own house with your eyes open. You are looking for where heat escapes, where electricity runs for no reason, and where a habit costs more than it should. You do not need special equipment to start, and you do not need to fix everything at once. The point of the audit is to find the few changes that matter most, and to do the free ones first.

This guide is the hub for the whole KiloWise set. It gives you a room-by-room checklist — hall, living room, kitchen, bedrooms, bathroom and loft — and shows you how to turn your notes into a ranked plan. The other guides go deeper on each topic; this page summarises them and links to them, so you can go deep only where your house needs it.

Before you start, read your last bill. Our guide to how to read your energy bill shows you how to pull out your three key numbers — kWh used, unit rate and standing charge — and the bill audit tool will use them to rank your savings. An audit without your bill is guesswork; an audit with it is a plan.

Before you walk: what you need

Give yourself about an hour, in daylight, on a cool or breezy day if you can — draughts are easier to feel then. Bring your last bill, a notebook or phone, a lit candle or a thin strip of tissue paper for finding draughts, and a torch for the loft and the backs of cupboards. If you have a smart meter display, bring that too, or note the reading before and after you test something.

Start with the bill numbers. Work out your daily average kWh: total kWh divided by the number of days in the billing period. Note your unit rate and your standing charge. For context, heating and cooling account for about half of a typical home energy bill, according to ENERGY STAR, and water heating accounts for about 18%, according to the US Department of Energy. Those two shares tell you where to look first: if half your bill is heating and cooling, a heating fix usually beats a lighting fix.

Walk the house in order, one room at a time, and write down what you see rather than what you assume. "Hall window rattles" is a useful note; "house is draughty" is not. You are building a list you can rank, so be specific: which room, which window, which appliance, and whether the fix is free, cheap, or a bigger spend.

The room-by-room walk-through

Hall. Stand in the hall and feel for air movement around the front door, the letterbox and any cat flap. Hold the tissue near the door edges: if it flutters, air is getting through. Check the door seal and the letterbox brush, and look for daylight around the frame. Note whether the hall radiator is blocked by coats or furniture, and whether the hallway light is left on for hours. Hall fixes are often the cheapest in the house — see our guide to the cheapest draught-proofing fixes.

Living room. This is usually where the most electricity is used while you are awake. Count the lights and note which bulbs are still old halogen or incandescent types — a 60W halogen swapped for a 9W LED, used 3 hours a day, saves 55.8 kWh a year, which is $10.15 a year at the US average of 18.19 cents per kWh, or £14.69 a year at the UK cap rate of 26.32p per kWh. Check the television, games console, set-top box and speakers: are they left on standby overnight? Standby power accounts for 5–10% of residential electricity use, up to about $183 a year in the United States, according to EnergySage in August 2026. Feel the windows for draughts and cold spots, and check whether curtains close fully and whether the radiator has space to give off heat.

Kitchen. The kitchen holds the hardest-working appliances in the house. Check the fridge and freezer seals by closing the door on a piece of paper: if it slides out easily, the seal is weak and cold air is escaping. Note the fridge temperature setting and whether the back coils are dusty. Look at the kettle, oven and hob: are you boiling a full kettle for one cup, or heating a full oven for one small dish? Note any appliance left on standby, and any light left on in a room nobody is using. Kitchens also lose heat through extractor fans left running and through poorly sealed windows above the sink.

Bedrooms. Check each bedroom window for draughts and check whether curtains or blinds fit the window properly. Note the heating: is a bedroom radiator heating an empty room all day, or is the thermostat in the coldest room in the house? Check the thermostat setting itself — our guide to thermostat settings that save money explains the US Department of Energy guidance, including a winter setting of about 68°F when you are home and awake, and a setback of 7–10°F for 8 hours a day that can save up to 10% a year on heating and cooling. Note any phone charger, lamp or fan left plugged in and switched on when not in use, and whether the bedroom lights are LEDs.

Bathroom. The bathroom is where water heating shows up. Note how long showers run, whether the shower head is a standard or low-flow type, and whether hot water pipes to the tank are insulated. Check the hot water temperature with care: stored hot water should stay at 60°C or higher in the United Kingdom, according to the UK Health and Safety Executive, and above 140°F (60°C) in the United States, according to the US Centers for Disease Control and Prevention, because legionella bacteria multiply between 20°C and 45°C and do not survive above 60°C. Never lower a stored tank into that range to save money; a thermostatic mixing valve can bring tap water down to about 49–50°C to prevent scalding. Check for dripping hot taps, which waste heated water directly, and for an extractor fan left running after the steam has cleared.

Loft. Take the torch. Look at the insulation: is it even, does it cover the whole floor, and is it thick enough to cover the joists? Look for gaps around pipes, the loft hatch and the eaves, where warm air escapes into the roof space. Check whether the loft hatch itself is sealed and insulated — an unsealed hatch is a hole in your insulation. Do not walk on the ceiling below the insulation, and do not block ventilation gaps. Loft and wall insulation are bigger spends, so note what you find and compare them in our guide to what insulation pays back first before you commit any money.

From notes to a ranked plan

When the walk is done, sort your notes into three piles: free, cheap, and bigger spend. Free means a habit or a setting — turning the thermostat down at night, switching things off at the wall, closing curtains at dusk, boiling only the water you need. Cheap means a small purchase you can fit yourself — a letterbox brush, a draught excluder, an LED bulb. Bigger spend means insulation, a new appliance or a heating change, and those need a payback check before you buy.

What each other guide adds

Each topic below is covered in full in its own guide. This section is a summary only — read the linked guide before you spend money or change a setting.

If you rent, read our guide for renters: energy saving with no permission needed alongside this one. Almost everything in the free pile — thermostat habits, switching off standby, closing curtains, shorter showers — is available to renters, and the draught-proofing and LED guides mark clearly which fixes need a landlord's agreement and which do not.

Two cautions from the full guides are worth carrying into the audit. First, heat pumps need special care with setbacks: do not use a deep setback without a smart or programmable thermostat designed for heat pumps, because recovery can call on expensive auxiliary heat. Second, never lower a stored hot-water tank below 60°C (140°F) to save money — the legionella risk is real, and the safe route is a thermostatic mixing valve at the tap.

After the audit: keeping the habit

An audit is not a one-off event. Repeat the walk once a year, ideally before winter, and repeat the bill check every month. Note your daily average kWh each month in the same place, so a slow rise shows up before it becomes a large bill.

Related: start with the bill audit tool, then read how to read your energy bill if you have not pulled your numbers yet, or go straight to the thermostat settings guide if heating is your biggest share.

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