THE SHORT ANSWER
Estimate air sealing from identified openings and joint lengths, with access and material selection described. Keep the sealing scope separate from insulation, testing and repair of unknown cavities.
Use this fictional defined penetrations in one loft in Exeter to plan the estimate. The agreed work is: Seal 18 accessible small loft penetrations and 36.6 metres of agreed top-plate joints after a site review. Include temporary insulation movement, approved sealant material allowance, application labour, documentation and clean-up. No new insulation or concealed opening repair. The matching loft air sealing example and PDF shows the same inputs. These quantities and rates are teaching examples; use your own site measurements, product selections, supplier information and labour figures for a customer job.
1. Mark the openings
Count the penetrations and measure the specific joints planned for treatment. A vague loft-wide line makes it difficult to verify what the crew will actually seal.
2. Identify access and preparation
Existing insulation may need careful movement and replacement around work locations. The example allows that effort without assuming wholesale insulation removal.
3. Choose suitable materials
Match sealant and backing to the actual assembly and applicable requirements. The fictional material allowance must be replaced with a job-specific product list.
4. Define evidence at handoff
Record the treated locations and the limited documentation included. Any diagnostic testing or new insulation should be a distinct scope with its own quantities.
Calculate the measured lines
The PDF uses 6 separate items. For example, Small penetration sealing is 18 each × £30.40 = £547.20; Top-plate joint sealing is 36.6 metres × £11.80 = £431.88. Check that each unit describes the work being priced: area for a surface, metres for a run, and a count or defined lump sum for a discrete task. A material purchase allowance can differ from the installed quantity when product sizes, cuts or layout require it.
Adding the 6 rounded line amounts gives £1,571.08. The example PDF uses a 0% tax input and no markup; those settings do not determine how to price or treat an actual job. Do not copy the rates as a local price guide.
Check the scope before sending
- Map and count accessible openings.
- Measure joint lengths.
- Review material and assembly requirements.
- Separate testing and insulation.
Outside the base scope: No blower-door testing, new insulation, concealed cavity repair, ventilation change or hazardous-material handling.
Confirm the site address, selected products, access, quantities, customer details and validity date. If opening the work reveals a different condition, record the change and update the relevant line before asking the customer to approve the revised work. Preview every page of the PDF so the written scope, line amounts and total tell the same story.
Common questions
Can loft air sealing be priced by floor area?
Area gives context, but identified openings, joint lengths and access define this example scope.
Is insulation part of air sealing?
Only if separately listed. This sample moves existing material temporarily but does not add new insulation.
FROM SITE NOTES TO AN ITEMISED PDF
Make your own loft air sealing estimate.
Enter the scope in Estimates on iPhone or Android, edit each quantity and rate in pounds, add your business and customer details, and review the PDF before sharing it.
