What Commercial HVAC Costs in the UK

Why per-square-metre pricing does not work

The most common opening question is some version of "what does commercial HVAC cost per square metre?" It is a fair question and there is no honest number to give, because floor area is a weak predictor of what a building needs.

Cooling and heating loads come from occupancy, lighting, equipment, solar gain and fresh-air requirements — and those vary enormously between buildings of identical size. A 400 m² open-plan office with 40 staff and a south-facing glazed elevation has several times the cooling load of a 400 m² warehouse with six staff and no windows. Any figure that averages across both is wrong for both.

What a per-m² figure can do is sanity-check a budget you already have. What it cannot do is size a system or produce a comparable quote. That requires a load calculation — see commercial air conditioning for how one is done.

What actually moves a commercial HVAC quote

Two bids for the same building can differ by a factor of two without either being unreasonable. Almost all of the difference sits in these variables rather than in the plant.

• Access and craneage. Ground-level plant versus a rooftop lift needing a crane, a permit and possibly a road closure. This alone can be a five-figure swing on an otherwise identical system.
• Electrical capacity. If the incoming supply has headroom, this is a modest cost. If it does not, you are into a Distribution Network Operator upgrade with its own price and a lead time measured in months.
• Pipe, duct and cable routes. Long or awkward runs through an occupied building add labour, containment and making good.
• Builder's work. Penetrations, fire stopping, structural support, decoration. Frequently excluded from the headline figure and then added later.
• Out-of-hours working. Standard in retail and hospitality, and it carries a real premium.
• Acoustic mitigation. Where a BS 4142 assessment requires attenuation or an acoustic housing, particularly near residential neighbours.
• Controls and BMS integration. Often the difference between a system that performs and one that merely works — and often the first thing cut.

This is why the cheapest quote is frequently not comparable rather than genuinely cheaper. The single most useful question you can ask every bidder is what heat load they designed to and how they calculated it. On a multi-zone building the answers diverge far more than the prices do, and that divergence is what you are actually choosing between.

Cost by system type

Split and multi-split systems

Roughly £1,800–£4,000 for a single wall or cassette unit serving a shop or small office, and £6,000–£20,000 for a multi-split serving a small suite. Simple, competitive, and the right answer below about five indoor units. Detail on the air conditioning cost page.

VRF and VRV

Commonly £20,000–£250,000 for an office floor, driven by zone count, whether heat recovery is specified, and builder's work. Three-pipe heat-recovery systems cost more up front and pay it back where the building genuinely has simultaneous heating and cooling demand. See VRF and VRV systems.

Chilled water

The chiller itself typically starts around £80,000; a complete chilled-water system including distribution starts nearer £150,000, and runs well into seven figures on large or complex buildings. The machine is often a minority of the total once pumps, pipework, terminal units, controls and plant-room work are counted. See the chiller cost guide.

Air handling units

Very wide, from around £15,000 for a modest unit to £400,000 for a large or specialist one — with construction specification (a pool or laboratory AHU is a different machine from an office one) mattering as much as duty. See the AHU cost guide.

Commercial heat pumps

Highly dependent on whether the building's emitters and electrical supply suit them. The comparison against a gas replacement has to be run on your actual tariffs rather than on generic claims — see commercial heat pumps and the heat pump versus gas boiler guide.

The costs that are not in the capital number

A capital figure alone will mislead you on a system that runs for fifteen to twenty years.

Energy is normally the largest lifetime cost. Seasonal efficiency — SEER for cooling, SCOP for heating, under BS EN 14825 — and part-load behaviour matter far more than headline rated output, because commercial plant spends most of its life at part load. A cheaper system with worse part-load performance frequently costs more over five years.

Maintenance runs from a few hundred pounds a year for a handful of splits to five figures for a large mixed estate. It is not optional: manufacturer warranties are routinely conditional on documented planned maintenance. See maintenance and PPM.

Compliance carries its own cost — F-Gas leak checking at intervals set by refrigerant charge, and a TM44 inspection every five years where air conditioning exceeds 12 kW effective rated output. See servicing and TM44.

Refrigerant is a rising cost that rarely appears in a business case. The HFC phase-down makes high-GWP gases progressively more expensive, so a system charged with an obsolescent refrigerant carries a higher lifetime cost than its purchase price implies. Lower-GWP refrigerants can also place a system in a less frequent leak-checking band for the same physical charge — a genuine ongoing saving. See replacement.

How it gets funded

There is no commercial equivalent of the domestic Boiler Upgrade Scheme — commercial HVAC is funded through the tax system rather than through grants, which surprises people who have read about domestic schemes.

The relevant routes are the capital-allowance ones for plant and machinery, set out on our grants and funding page. One distinction worth knowing because it causes confusion: HVAC plant is main-rate plant and machinery, whereas solar PV sits in the special-rate pool and takes the Annual Investment Allowance route instead — so general advice about full expensing does not transfer cleanly between the two technologies. Confirm treatment with your accountant and against current GOV.UK guidance, since rates and schemes change.

Our funding guide works through the options in more detail.

Getting a number for your building

For a first-pass figure without talking to anyone, the cost estimator will give you an indicative range. For anything you intend to budget against, you need a survey and a load calculation — and you should expect any credible bidder to want one before quoting.

When you do compare quotes, compare on: the design load and how it was derived, what builder's work is included or excluded, whether commissioning is a priced deliverable with measured records, what the controls scope covers, and what the maintenance obligation is to keep the warranty valid.

Frequently asked questions

How much does commercial HVAC cost per square metre?

There is no reliable per-square-metre figure. Load comes from occupancy, lighting, equipment and solar gain, which vary enormously between buildings of the same floor area — a busy glazed office and a sparsely-occupied warehouse of identical size have completely different requirements. A per-m² figure can sanity-check a budget but cannot size a system or produce a comparable quote.

Why are our two quotes so far apart?

Usually because they are not quoting the same thing. Differences in assumed heat load, in what builder's work is included, in whether commissioning and controls are properly scoped, and in access and electrical assumptions can easily double a price. Ask each bidder what heat load they designed to and how they calculated it — the answers normally diverge more than the prices.

Is there a grant for commercial HVAC?

There is no commercial equivalent of the domestic Boiler Upgrade Scheme. Commercial HVAC is funded through the tax system via capital allowances on plant and machinery rather than through grants. Confirm the current position with your accountant and on GOV.UK, since schemes and rates change.

What is the biggest hidden cost in a commercial HVAC project?

Electrical capacity is the one that most often surprises people. If the incoming supply lacks headroom for the new plant, a Distribution Network Operator upgrade adds both cost and a lead time measured in months. It should be checked at design stage rather than discovered close to commissioning.

Detailed cost guides: air conditioning, air handling units and chillers. See also funding and capital allowances, the cost estimator, and the full system range. Or request a quote.