Cavity wall insulation Stockport: for landlords and owners
Cavity wall insulation Stockport homeowners and landlords ask about fills the gap between the two layers of a brick wall. It cuts heat loss and is often one of the first measures an assessor recommends for a rented home. Here is how it works, who it suits and how to get it funded in Greater Manchester.
Last checked: 21 October 2026.
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What is cavity wall insulation?
Many homes built from about the 1920s have walls made of two layers with a gap between them, called a cavity. Cavity wall insulation fills that gap so less heat escapes through the walls.
A trained installer drills small holes in the mortar, blows insulation into the cavity and then fills the holes. The work is done from outside. Most typical houses need a few hours to a day.
Which Stockport homes are suitable?
Not every wall is suitable. A suitability check comes first. It looks at:
- Whether the wall actually has a cavity, and how wide it is.
- The condition of the brickwork and mortar.
- How exposed the house is to wind-driven rain.
- Whether the cavity already contains insulation.
Homes built before the 1920s often have solid walls with no cavity. For those, see our solid wall insulation guide. An assessment tells you which you have.
How much does cavity wall insulation improve an EPC?
Cavity wall insulation reduces heat loss through the walls, which the EPC measures as fabric performance. Under the government's plan, fabric performance will be the primary standard for the new EPC.
The exact improvement depends on the house, so we do not quote a standard number. Our assessor models your property and shows the likely effect before you commit. Read our EPC C 2030 guide for the rule it supports.
Cavity wall insulation grants for Stockport landlords
Possibly. Stockport is in Greater Manchester, where the Warm Homes: Local Grant covers cavity wall insulation as one of its measures.
- A landlord's first property can receive 100% of eligible costs, up to £30,000 across all measures.
- Second and later properties receive 50%.
- The property must be rated D or E, and the tenant household must meet an income or benefit route.
- Landlords must support the Good Landlord Charter.
ECO4 can also fund measures until 31 December 2026 where the tenant qualifies. See our full grants for landlords guide.
What does cavity wall insulation cost?
Prices vary with the size and shape of the house. Indicative price from £1,800 for a semi-detached house (UK market research, 2026). This is not a quote: your written quote after a survey is the confirmed price.
You receive a written price after the assessment. If a grant applies, we show you what you pay, if anything, before work starts.
Cavity wall insulation Manchester and the wider area
We assess and insulate homes across Stockport, Manchester and the rest of Greater Manchester. The same grant rules apply across the region, though each borough has its own council contacts.
How the process works
- Assessment: a retrofit assessor visits, checks the walls and models the EPC effect.
- Plan: you receive a written recommendation and a clear cost or funding position.
- Installation: our installer drills, fills and makes good the holes.
- Evidence: you receive certificates and records you can keep for your cost cap evidence and your agent.
What if my walls are not suitable?
Some walls fail the check. They may be solid, already filled, too exposed or in poor repair. That does not close the door on EPC C.
Other fabric measures can make up the difference, such as loft insulation, draught-proofing and, for solid walls, internal or external insulation. Our assessor ranks them for your property so you spend on what helps most. See our loft insulation guide for the next measure many landlords choose.
What should a landlord check before booking?
Before you agree to any cavity wall work, check four things:
- The installer holds PAS 2030 for installation and works to a PAS 2035 assessment.
- You will receive a written suitability check and a plan.
- Records and certificates come with the job, for your cost cap evidence.
- The tenant has been told about access and timing.
Why choose Compliant Lets
Compliant Lets is a trading name of LAMTANS Holdings Ltd. The work is delivered by LAMTANS Engineering Ltd, which holds PAS 2030, PAS 2035, MCS and TrustMark. Check the registers yourself: TrustMark, RECC, ICO, Gas Safe Register and Simply Certification.
Sources
- GMCA: Warm Homes Local Grant, privately rented scheme, checked 21 October 2026
- GOV.UK: Improving the energy performance of privately rented homes, government response, checked 21 October 2026
Designed & developed by LAMTANS Technologies LLC, USA — part of the LAMTANS Group
Frequently asked questions
How long does cavity wall insulation take?
Most typical houses take a few hours to a day. Your installer confirms the time after the assessment.
Is cavity wall insulation messy?
No. Small holes are drilled in the mortar from outside, insulation is blown in, and the holes are filled. Our installers tidy up when they finish.
How do I know if my house has a cavity wall?
Houses built from about the 1920s often have one, but not all. A retrofit assessor can check, so you do not have to guess.
Can cavity wall insulation cause damp?
In unsuitable or very exposed walls it can. That is why a suitability check comes before any work. A wall that fails the check should not be filled.
Do landlords need the tenant's permission?
You need the tenant's cooperation for access, and for grant routes the tenant household's circumstances matter. We explain what is needed at the assessment.
Will it help my property reach EPC C?
It helps because the new EPC puts fabric performance first. How far it takes you depends on the property, which the assessment shows.
Is there a grant for cavity wall insulation in Stockport?
Possibly. Greater Manchester's Warm Homes: Local Grant covers it for qualifying properties and tenants. ECO4 can also help until 31 December 2026.
Does cavity wall insulation count towards the £10,000 cap?
Yes. Spend on measures installed since 1 October 2025 counts towards the cap, as does third-party funding. Keep every invoice.