What changes an air tightness test quotation
The number of buildings matters, but it is only the starting point. The tester also needs to understand size, layout, access and the proposed test boundary. A detached home with clear access creates different attendance arrangements from flats with shared circulation and staggered handovers. Explain the arrangement before comparing fees rather than treating every plot as an identical appointment.
Drawings affect preparation too. Incomplete or inconsistent plans can leave envelope dimensions and tested spaces unresolved. Send revisions clearly marked and identify changes since any earlier quotation. Where the building contains unusually large spaces or a complex boundary, ask whether the proposed equipment and testing approach are covered by the quoted scope.
Air tightness test inclusions to confirm in writing
An apparently similar price can cover a different service. Ask for an itemised description of preparation, attendance, measurement and reporting. The following questions help you compare offers without assuming that a lower headline fee includes the same work. None of these items should be treated as included until the written quotation says so.
| Quote item | Question to resolve |
|---|---|
| Building information | Does the fee cover checking the plans and establishing the envelope area for the stated test boundary? |
| Site attendance | Which plots and buildings are included, and what happens if only part of the site is ready? |
| Test reporting | Which reports are issued, who receives them and how are building identifiers checked? |
| Leak investigation | Is any diagnostic work included, and where does additional investigation become a separate instruction? |
| Return testing | What scope and charges apply if repairs or an incomplete building require another visit? |
| Expenses and tax | Are travel, access arrangements and VAT addressed explicitly in the written total? |
Air tightness costs that sit outside the test itself
Permanent sealing repairs, replacement components and opening up concealed work may need a builder or specialist trade. Do not assume the person measuring leakage will also carry out construction repairs. Ask who is responsible for diagnosis, who authorises remedial work and whether a separate fee applies. Agree this before an unsuccessful result creates pressure to make immediate decisions.
Energy calculations are another distinct scope. Approved Document L connects pressure test evidence with the completed energy assessment. Confirm who passes the result to the energy assessor and whether updating that assessment is included elsewhere. Our guide to a good air tightness result explains why buying a test does not settle every energy compliance question.
How site readiness affects air tightness test spending
A missed readiness check can create an avoidable attendance without producing useful completion evidence. Before booking, inspect the envelope, confirm functioning access doors and identify outstanding service openings. Check that another contractor will not be cutting through the envelope during the appointment. Our air test preparation steps give a construction-stage sequence for these checks.
For a development, group genuinely ready plots rather than grouping them only because their planned handover dates match. A single visit may suit several homes, but incomplete units or conflicting access arrangements can change that plan. Ask how a partial attendance is handled and whether moving a booking affects the fee. Do not infer cancellation terms from another supplier’s quotation.
For a self-build, maintain a short list of work that must be finished before attendance and have the builder confirm it. If there are suspected leaks behind finishes, discuss diagnostic work separately instead of hoping the completion test will identify and repair everything. A clear scope helps you choose when to investigate without inventing a saving that the quotation does not promise.
Comparing air tightness test cost within a completion package
Projects often need several pieces of completion evidence, but each appointment has its own readiness conditions. Approved Document F addresses mechanical ventilation commissioning and airflow evidence separately from pressure testing. Read our ventilation certificate guide before assuming a fan check is included in an air test fee.
Use the new build compliance package to identify related services and then ask for the scope of each. National Building Compliance acts as a single contact to arrange accredited, qualified assessors and the reports your project needs. When requesting air tightness testing, include the address, plans, plot count, current programme and any earlier results. Ask for exclusions and return-visit arrangements alongside the proposed fee so the decision rests on the work being purchased.
About our Air Tightness Testing service
For the service itself, see Air Tightness Testing.
- Supply the plans, plot schedule and design target when requesting air tightness testing.
- Compare quotations against the same buildings, report scope and attendance assumptions.
- Ask whether VAT, travel, diagnostic investigation and retesting are included or separately chargeable.
- Leave space in the programme for repairs rather than assuming the initial attendance closes every outstanding issue.