UK home insulation · quote workbench
Loft insulation cost, from packs to quote
Count each layer with the pack coverage you can verify, then compare labour, boarding, delivery, VAT and confirmed funding without hiding the scope.
Loft scope
Count each material layer separately and keep quote extras visible.
Blank quote sheetLike-for-like
Saved quote options
Keep up to three options in the current browser session. Scope differences stay visible instead of disappearing into one headline number.
| Option | Comparison area | Material / installation | Gross total | Out of pocket | Remove |
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Reusable evidence
Data behind the worksheet
The calculation fields and outputs are documented. Government stock context is kept separate from your individual quote; national estimates do not decide whether a particular home is suitable.
Dated loft-roll snapshot
Three Wickes product rows were checked on 29 August 2026. They are editable starting inputs, not a complete market price index or stock guarantee.
Inzonex Engineering Learning
A cost method you can audit
What the result answers
It answers one practical question: what does this documented material plan or installer quote cost when all compared options use the same area, scope, VAT entry and confirmed funding?
What it does not answer
It does not model annual heat or bill savings, certify a construction, determine moisture or ventilation risk, confirm tax treatment, select an installer or decide funding eligibility.
Sources checked
- Household Energy Efficiency Statistics, detailed report 2025 — Department for Energy Security and Net Zero
- Insulation: energy-efficient home guidance — UK Government
- Tax on shopping and services: energy-saving products — UK Government
- Great British Insulation Scheme: homeowners and tenants — Ofgem
- How to insulate a loft — Energy Saving Trust
- Knauf 100 mm Space bottom-layer loft roll — Wickes
- Knauf 170 mm Space top-up loft roll — Wickes
- Knauf 200 mm Space super top-up loft roll — Wickes
Four visible steps
Measure the usable loft
Use the ceiling-level area. Record inaccessible or boarded areas rather than guessing them away.
Enter each layer
A bottom layer and a cross-laid top-up layer often have different pack coverage, so the tool rounds each separately.
Normalise every cost
Delivery, labour, access or raised boarding, VAT and confirmed funding remain explicit.
Save the decision
Compare options and export the chosen calculation, source ledger and blank worksheet.
The LearningResource, HowTo and EducationalOrganization structured data describe this visible free learning module and the Inzonex Engineering Learning collection. They do not claim accreditation or professional certification.
Questions answered
Cost and scope questions
How many rolls of loft insulation do I need?
For each enabled layer, the calculator multiplies the measured loft area by the waste allowance, divides by that product's documented pack coverage and rounds up to a whole pack. A bottom layer and a cross-laid top-up layer are counted separately because their pack sizes can differ.
Is 270 mm always the correct loft-insulation depth?
No. UK guidance commonly uses about 270 mm as a mineral-wool reference, but thickness is not interchangeable across materials and constructions. Existing insulation, ventilation, boarding, moisture, services and the exact product specification still need checking. This page estimates purchase and quote cost, not regulatory compliance.
Does the loft calculator include labour, boarding and delivery?
Only when you enter them. Material packs, delivery, labour, access or raised boarding and other confirmed costs remain separate so two quotes can be normalised to the same scope.
Does the calculator decide VAT or grant eligibility?
No. Enter the VAT rate printed on the quote and only confirmed funding. The Great British Insulation Scheme page says that scheme was scheduled to end in April 2026, so it is not treated as a live automatic discount.
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