Guide
HVAC maintenance contract cost: the drivers behind every quote
Updated
The reason two HVAC maintenance proposals for the same building differ by half is almost never the labour rate. It is the asset list, the visit frequency and what happens when something breaks.
Why we do not publish a cost per square foot
Cost per square metre or per square foot is the benchmark facilities teams most often ask for and the one least worth having. Two buildings of identical floor area can carry three times the plant, at different ages, in different accessibility, with different criticality. There is also no published, checkable UK dataset of HVAC maintenance prices, so any figure we printed would be invented. What follows is the list of things that actually move your number.
The eight drivers
| Driver | Why it moves the price |
|---|---|
| The asset list, not the floor area | Price follows the number and type of assets: split units, VRF branch boxes, air handling units, chillers, pumps, fans, controls. A missing asset register is the single biggest source of quote variance. |
| Visit frequency | Quarterly against twice yearly roughly doubles the labour. There is no statutory frequency, so this is a genuine choice you are making rather than a requirement you are meeting. |
| What each visit contains | Filter changes, coil cleaning, belt and bearing work, control checks and water treatment are separate scopes. Filters supplied or charged extra is a common and material difference. |
| Statutory work in or out | F gas leak checking and air conditioning inspections are distinct duties with their own frequencies and their own qualified people. Some contracts include them, many do not. |
| Access, hours and occupancy | Working in occupied offices, at height, on roofs, in retail trading hours or under permit systems all add time and sometimes require out-of-hours attendance. |
| Reactive cover and response times | Response cover is a separate purchase from planned visits. A named response time with parts availability behind it costs more, and is worth more, than a promise to attend when possible. |
| Plant age and condition | Older plant fails more, needs obsolete parts and often needs a condition survey before anyone will commit to a fixed price. |
| Reporting and systems | Asset tagging, a CAFM feed, photographic evidence and compliance dashboards are real work. Ask for them if you need them, and expect them to be priced. |
The specification that makes quotes comparable
- Issue an asset list. Even an imperfect one. If you cannot, buy a survey first and tender afterwards, because a priced guess is not a quote.
- State the visit frequency you want per asset type, rather than asking each provider to propose their own and then comparing incomparable proposals.
- Say explicitly whether F gas checks and the air conditioning inspection are in scope. See the inspection guide.
- Ask for planned and reactive priced separately, with labour rates in and out of hours and the callout charge stated.
- Ask what the report looks like and how you get it. If your compliance evidence lives in a filing cabinet, it does not exist at audit.
If a contract price looks unusually low, check the visit frequency, the filter supply and whether statutory work is excluded. Those three exclusions can account for most of a surprising gap without anyone being dishonest.