Commercial heating systems: options, costs and how to choose

What are the main types of commercial heating system?

Type	How it heats	Rule or source to check
Gas or oil boiler with radiators or fan coils	Hot water for space heating	Approved Document L: 91% overall for gas multi-boiler systems, no boiler below 84%
Gas warm-air heater	A burner raises the air temperature, a fan spreads it	Ecodesign: at least 78% seasonal efficiency since 1 January 2021
Gas radiant tube or plaque	Infrared warms people and surfaces	Ecodesign: tube at least 74%; mounted above head height
Electric radiant or panel heaters	Electric element, no combustion	Part L: presence detection or zone control
Heat pumps, including reversible air conditioning	Move heat rather than make it	Efficiency set by SCOP; see commercial heat pumps

The government-backed Energy Technology List (ETL) describes hot water boilers as producing hot water for space heating, process heating and domestic uses. Ecodesign Regulation 2016/2281 also describes air conditioners that can operate in reverse and then function as heat pumps; the VRF and VRV page covers multi-zone systems.

Which type suits which building?

• Offices. Zoning matters. Approved Document L expects separate control zones where solar exposure, pattern of use or type of use differ, each with its own timing and temperature control. See the office page.
• Retail. The ETL names retail units and retail sheds among typical uses for radiant and warm-air heating. See the retail page.
• Warehouses and workshops. The ETL says both warm-air and radiant heaters are widely used in warehouses; the warehouse heating guide compares them, and the infrared heating guide covers electric panels for workshops and offices.
• Schools. HSE describes a primary school where carbon monoxide from an inadequately maintained boiler leaked into a classroom, so maintenance and flue checks matter wherever gas plant serves occupied rooms.

What do fuel prices say about running cost?

DESNZ's annual report gives average non-domestic prices across all size bands, including the Climate Change Levy: 24.3 pence per kWh for electricity and 5.3 pence for gas in 2025 (provisional). A site's own contract will differ, so these figures are illustrations. The efficiencies are assumptions, and the seasonal coefficient of performance (SCOP) is, in the Energy Saving Trust's words, the heat pump's efficiency averaged across the whole year.

Option	Assumption	Pence per kWh of heat
Gas boiler	90% efficient	5.9
Gas warm-air or radiant heater	85% efficient	6.2
Heat pump	SCOP 3.0 / 3.5 / 4.0	8.1 / 6.9 / 6.1
Electric panel or boiler	100% efficient	24.3

A heat pump matches a 90% efficient gas boiler at a SCOP of about 4.1, and an 85% gas heater at about 3.9. Electric resistance heat costs roughly four times as much per kWh of heat as gas. Efficiency figures in the rules are not all on one basis: Approved Document L states boiler efficiency on gross calorific value but judges radiant heaters on net, and says net figures should be converted to gross, so compare like with like. The cost depends on the site, so the cost guide and the heat pump versus gas boiler guide are the next step. Carbon and lead times are not covered by any single official figure; ask each contractor for both, in writing.

Which rules apply when heating plant is replaced?

• Sizing. Approved Document L says systems should be sized from a heat loss calculation and not be significantly oversized.
• Controls. When a boiler is replaced in an existing non-domestic building, each room should have thermostatic room controls. If the whole wet system is replaced, it should be sized for a flow temperature of 55°C or lower. Boiler systems over 100 kW should also have optimum start or stop control, and circuits should be cleaned and flushed before a new appliance goes in.
• Gas work. HSE says work on gas fittings in workplaces such as shops, restaurants, schools and hospitals must be done by a Gas Safe registered engineer who is qualified for it, and by a competent person in places such as factories. Checking is the employer's responsibility.
• Temperature. The Workplace Regulations require a reasonable temperature, and HSE says the code of practice suggests at least 16°C, or 13°C for rigorous physical effort.

Approved Document L applies in England. Its 2026 edition takes effect on 24 March 2027, and for new non-domestic buildings the government's March 2026 response says the Future Buildings Standard will require low carbon heating sources. The boiler replacement guide sets out the full checklist for a boiler swap.

What does maintenance involve?

The Carbon Trust says gas-fired boilers should be serviced once a year and oil boilers twice a year. HSE says gas pipework, appliances and flues should be regularly maintained and that rooms with gas appliances need adequate ventilation. Planned maintenance is covered on the maintenance and PPM page.

What if the building heats with oil or LPG?

The Boiler Upgrade Scheme covers heat pumps and biomass boilers in homes and non-domestic buildings in England and Wales. gov.uk lists £7,500 towards an air source or a ground source heat pump, and until March 2027 an extra £1,500 where the property is heated by oil or LPG with no mains gas connection; Ofgem describes that as £9,000 until 31 March 2027. The maximum capacity is 45 kWth for individual systems. Hybrid systems with a gas boiler are not funded, and air-to-air heat pumps are for homes only.

How do you choose between them?

1. Get a heat loss figure for the building, not the old plant's rating.
2. Separate what must be kept warm (stock, process) from where people work.
3. Price the options on the site's own tariff, as above.
4. Check the rules for the type: efficiency, controls, gas competence, ventilation.
5. Compare quotes line by line on the same basis; the quote comparison guide shows how.

Readers can send an enquiry through the form on this page. The cost guide shows what drives each system's price.

Sources

All pages checked 22 October 2026.

• DESNZ: annual report, performance report (updated 19 August 2026); Energy Technology List with hot water boiler, radiant and warm air, radiant criteria and warm air criteria pages.
• HSE: gas safety; temperature law. legislation.gov.uk: Workplace Regulations reg 7; Gas Safety Regulations reg 3; Ecodesign 2016/2281, 2015/1188.
• MHCLG: Approved Document L, 2021 edition, 2026 edition; consultation response (March 2026). Gov.uk and Ofgem: Boiler Upgrade Scheme, Ofgem.
• Energy Saving Trust: heat pumps guide (updated 20 October 2026). Carbon Trust: heating and ventilation guide.

Guides on this topic

• What does a commercial boiler replacement cost?
• Commercial underfloor heating: costs and where it works
• Do destratification fans cut heating costs?
• Does infrared heating work in offices and workshops?
• How to heat a warehouse: warm air, radiant or destratification?

Frequently asked questions

What is the cheapest commercial heating system to run?

At DESNZ's 2025 provisional averages, gas gives the cheapest heat per kWh: about 5.9 pence from a 90% efficient boiler against 24.3 pence for electric resistance heat. A heat pump needs a SCOP of about 4.1 to match that boiler, so the answer depends on the building and the site's tariff.

What are the different types of commercial heaters?

Boilers feeding radiators or fan coils, gas warm-air heaters, gas radiant tube and plaque heaters, electric radiant or panel heaters, and heat pumps including reversible air conditioning. The table above sets out how each heats and the rule to check.

Does commercial gas heating need a Gas Safe engineer?

HSE says work on gas fittings in workplaces such as shops, restaurants, schools and hospitals must be done by a Gas Safe registered engineer qualified for the work, and by a competent person in places such as factories. Regulation 3 of the Gas Safety Regulations 1998 bars anyone from the work unless competent.

Can an old commercial boiler be replaced like for like?

Not automatically. Approved Document L expects heating to be sized from a heat loss calculation, sets minimum efficiencies for replacement boilers and asks for room controls when a boiler is replaced. A like-for-like nameplate swap may not meet them.