Business heating efficiency: how to cut commercial heating costs

For many small premises, heating and hot water are the biggest slice of the energy bill, and a large share of it is avoidable. The good news is that the cheapest fixes (timers, thermostats, servicing) deliver a lot of the saving. This page sets out the order to tackle things, with sums you can repeat for your own site.

Start with the settings

Government guidance for businesses recommends about 19°C for heating offices and 24°C or higher for cooling. Many premises run well above that. Trade-press summaries of Carbon Trust guidance say each 1°C of overheating adds roughly 8% to heating costs. That figure is from older Carbon Trust material, so treat it as a rule of thumb rather than a measured result for your building.

Worked example (illustrative figures): a shop pays £4,000 a year for gas heating and runs 2°C warmer than needed.

• Saving per degree: £4,000 x 8% = £320.
• Saving for two degrees: roughly 2 x £320 = £640 (simple approximation).

Check the thermostat is in a representative place: one next to a door or radiator can give false readings.

Fix the timing

• Set heating to come on shortly before opening and off before closing, since buildings stay warm for a while.
• Turn it off at weekends and bank holidays if no one is in, keeping a frost setting in winter.
• Check time clocks after the clocks change. Old timers drift and leave heating running all night.

The same trade-press summary of Carbon Trust figures says resetting timers and replacing old controls could save 15% on a typical service-sector firm's energy bill, and that well-controlled heating typically uses 15 to 30% less fuel. Again, these are general figures from older material. Compare your own bills before and after to see what you actually saved.

Worked example: trimming run-time

Imagine a small office that opens 9am to 5pm Monday to Friday, but its heating is set 6am to 8pm, seven days a week. That is 14 hours x 7 = 98 hours a week. If you set it to come on at 8am and off at 4.30pm on weekdays (8.5 hours x 5 = 42.5 hours), run-time falls by 55.5 hours, or about 57%. Heating does not scale perfectly with hours, because a cold building needs extra energy to warm up, so the real saving will be smaller than that. If gas heating costs £3,000 a year (an illustrative figure), even a quarter of that cut is £750. Test it in winter and adjust the start time until it is warm when staff arrive.

Spotting waste with your meter

Take a gas meter reading at closing and again at opening on a cold night. If the heating is on all night you will see steady use. Repeating the test after you change the timer shows the effect straight away. Keep a log of readings and outside temperatures to compare month on month. See the gas units to kWh converter if your meter reads in cubic metres or feet.

Service and maintain

A poorly maintained heating system can cost up to 15% more to run, according to the same Carbon Trust figures, and heating, ventilation and air-conditioning (HVAC) energy use can rise by up to 30% without regular upkeep. Practical steps:

• Have the boiler serviced annually; it may be required to keep a warranty.
• Bleed radiators and clear obstructions such as furniture and stock in front of them.
• Clean or replace air-conditioning filters.
• Switch off boilers that aren't needed, for example a second boiler in a mild period.

Gas appliances need a registered Gas Safe engineer. Do not attempt gas work yourself, and ask your landlord who is responsible for servicing in rented premises.

Stop the heat escaping

• Draught-proofing doors, windows and floors is cheap and effective. Window film is a low-cost temporary secondary glazing.
• Insulation: roof and wall insulation pays back over a longer period but suits owned premises or long leases.
• Doors: in a shop, closing the door or fitting an air curtain or lobby cuts losses; leaving doors open with the heating on is costly.
• Zoning: don't heat storerooms and unused rooms to the same level.

Controls and smart thermostats

Zoned controls let you heat each area to the temperature it needs when it is occupied. Smart thermostats can add scheduling and remote control. Government guidance lists smart thermostats as a longer-term option. Choose products from reliable lists such as the government's Energy Technology List and make sure they are compatible with your boiler. See also energy monitoring for business for how to track results.

Replacing the equipment

If your boiler is old and inefficient, replacement may pay, but only after controls and insulation are sorted (otherwise you size the new one for the waste). Heat pumps are a longer-term option. The Boiler Upgrade Scheme offers £7,500 towards an air or ground source heat pump, and small and medium non-domestic buildings in England and Wales can qualify, with a 45 kWth size cap and an MCS-certified installer applying for you (the government grants finder lists it as closing on 30 December 2029). Check eligibility before planning on it. Read grants and loans for business energy efficiency and consider an energy audit before large spend.

Gas or electric: cost per kWh

Gas is much cheaper per kWh than electricity. The official average for April to June 2026 was 5.28p/kWh for gas against 24.51p/kWh for electricity. A heat pump produces more than one unit of heat per unit of electricity, which can narrow the gap, but electric radiators and panel heaters give one unit of heat per unit of electricity and are costly to run for long hours. Check what your premises use before comparing quotes; see is business gas cheaper than electricity.

Your heating bill and your contract

Heating costs rise in the cold months, so check the gas standing charge and unit rate in your contract; see business gas prices per kWh. If you rely on estimated readings, winter bills can be far off the true amount, so read the meter yourself: submit a business meter reading.

Next steps

1. Record the current thermostat and timer settings.
2. Check and correct the timer; reduce temperature by a degree and watch the bills.
3. Book the boiler service and tidy radiators.
4. Seal draughts.
5. Keep reading: saving energy in a small business.