Our July 2026 installation cost bands are planning ranges, not market tariffs. They start from commonly quoted single-room wall-mounted split totals including VAT, then adjust for London access patterns and the extras that repeatedly move real quotes: pipe routes, access equipment, electrics, condensate pumps, quieter kit and consent complexity. This page explains that method so readers can judge the calculators and guides fairly, and replace any range with a surveyed written proposal.
What the headline bands are for
The domestic UK band of about £1,500 to £3,000 including VAT for a straightforward single-room split, and about £1,800 to £3,500 in many London situations, is a budgeting envelope. It helps someone decide whether to request surveys. It is not a promise that every postcode or installer will land inside it.
Commercial and server room figures use the same discipline with different bases: zone count and premises type for small commercial comfort cooling, and heat load plus resilience for IT process cooling. Each calculator on this site exposes the assumptions so users can stress-test them.
Inputs we weight heavily
Room or zone count matters, but less than outdoor access, pipe length, drainage method and electrical readiness. London premiums in our models are not a flat surcharge on every job. They stand in for denser parking, restricted hours and harder plant positions that appear often in surveyed London work.
Extras are added as low and high allowances rather than single point estimates. That keeps the output as a range. Midpoints are only a reading aid.
- Start from a simple single-split base including VAT.
- Add rooms or zones with separate single-split or multi-split profiles.
- Layer checked site extras instead of burying them in a vague contingency.
- Keep server room and commercial models separate from domestic comfort jobs.
What we deliberately exclude
Decorative making-good, major builder openings, emergency repairs, temporary hire plant and full data-centre halls sit outside the domestic and small commercial bands. If a calculator mentions an exclusion, treat it as a hard boundary, not a soft hint.
We also exclude installer profit guarantees and any claim that a published range is a regulated tariff. Two honest quotes for the same postcode can still diverge after alignment on scope.
How to use the bands without being misled
Run the relevant calculator, note the midpoint and the width of the range, then brief installers with the same rooms, outdoor options and consent constraints. If surveyed quotes sit far outside the band after scope alignment, ask which assumption broke: access, electrics, acoustics, landlord process or equipment grade.
Revisit this methodology when tariffs, labour patterns or refrigerant rules shift enough to move consumer budgets. The dated stamp on guides and tools is part of the method, not decoration.
Frequently asked questions
Are these bands based on a private price database?
They are editorial planning ranges synthesised from published consumer guidance patterns, recurring quote drivers and site modelling. They are not a scraped live tariff feed.
Why show a midpoint at all?
Only as a quick orientation inside the range. Decisions should still use the low and high bounds and then a surveyed quote.
Will you publish raw quote data?
Not as identifiable customer records. Any future aggregate insights would stay anonymised and clearly labelled as samples, not promises.
Core buying guides
Start with these high-intent guides, then dig into the rest of the library.
Related guides
Sources and further reading
How this guide was prepared
This guide was written by the Local AC Installers Editorial Team. We compare official guidance, legislation and established consumer information, separate general information from project-specific advice, and show publication dates and sources. We do not accept installer accreditation claims at face value.