There is no single universal 'AC log book Act', but UK guidance expects inspection reports and useful operating records to be kept where people managing buildings can find them. GOV.UK's guide to air conditioning inspections says the inspection report should be kept safely with maintenance or energy records, ideally in a building log book, and passed on when control of the system changes. Separately, F-gas regimes require appropriate leak-check and company records for refrigerants. Treat the log book as the operational memory of the plant: equipment schedule, service visits, F-gas entries, TM44 or equivalent inspection reports and controls passwords held securely.
What official inspection guidance expects you to keep
For systems that require periodic air-conditioning inspections in England and Wales, the relevant person must keep the most recent inspection report and make it available as the regulations require. GOV.UK guidance recommends storing that report with maintenance and energy records, for example in a building log book, so later inspections and new managers are not starting from scratch.
Where a formal Part L-style building log book already exists, that is usually the best home for AC inspection results alongside other services records. If no log book exists, keep a dedicated operation-and-maintenance file that travels with the building.
Practical contents that prevent expensive confusion
Useful packs include a plant schedule with locations and rated outputs, installer and maintainer contacts, filter and coil service dates, condensate and pump notes, control set-points, F-gas leak-check history, and copies of previous inspection advice.
Landlords and managing agents should agree who updates the file after every visit. Missing records are a common reason quotes diverge: one company prices a clean service, another prices rediscovery of an undocumented system.
- Store the latest air-conditioning inspection report where successors can find it.
- Keep F-gas evidence with the equipment it relates to.
- Record outdoor positions and access constraints for future engineers.
- Hand the pack over when the relevant person changes.
How this links to servicing contracts
A maintenance contract should say what gets written down after each visit, not only that filters will be cleaned. Ask for digital copies as well as any paper left on site.
For multi-site portfolios, standardise the log structure so TM44 preparation and F-gas audits do not become a scramble every five years.
Frequently asked questions
Do domestic homeowners need a formal log book?
Small homes are often outside the 12 kW inspection regime, but keeping manuals, service invoices and F-gas paperwork still helps the next engineer and supports warranty claims.
What if the previous manager lost the TM44 report?
Arrange a fresh inspection where the duty still applies, and rebuild the equipment schedule from nameplates and drawings so future reports have a baseline.
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.