Flats and blocks · Wales
EWI for flats and blocks in Gwynedd
We provide EWI for flats and blocks across Gwynedd, including Bangor (Gwynedd), Holyhead and Caernarfon, with a free survey and fixed written price. Freeholders and managing agents in Gwynedd get a written specification and pricing they can share with owners.
- Free survey and fixed written price
- Guide price from £110 per m² + scaffold, 0% VAT
- Planning and building control checked for Wales
Free survey in Gwynedd
Tell us the postcode and what you need.
Included as standard
- We work with managing agents on resident communication
- Mineral wool systems where building height or guidance requires them
- One programme and one finish across the whole building
- Cavity barriers and fire-stopping detailed at compartment floors
- Planning permission is needed for flats and maisonettes

What we look for in Gwynedd
North Wales has many solid stone and slate-built homes, Victorian seaside terraces and post-war council estates.
Parts of Gwynedd fall in the higher wind-driven rain exposure bands, especially coastal and upland sites, so render specification, movement joints and detailing at cills, verges and the base of the wall matter more than usual.
For blocks in Gwynedd, we start with height, storeys and the planning position, because those decide the system.
- Nation
- Wales
- Region
- North Wales
- Towns covered
- Bangor (Gwynedd), Holyhead, Caernarfon, Llangefni
- Guide price
- From £110 per m² + scaffold · 0% VAT
Approvals in Wales
Permitted development rules for houses in Wales are similar to England's: a similar-appearance finish on a house is often permitted, while conservation areas, National Parks, Areas of Outstanding Natural Beauty, flats, commercial buildings and listed buildings need permission or consent. Your local planning authority has the final word.
The Building Regulations as they apply in Wales treat insulating or re-rendering more than half of a wall's area, or more than a quarter of the building's whole envelope, as renovating a thermal element, with Approved Document L (Wales) setting the target. Building control is involved before work starts.
Wales applies its own amended fire rules for external walls, including the combustible materials ban for relevant buildings and guidance for residential buildings between 11 and 18 metres, updated by the Building (Amendment) (Wales) Regulations 2025.
Who needs to agree to EWI on a block?
The freeholder or management company commissions the work, but leaseholders usually pay through the service charge. In England and Wales, major works above the statutory threshold trigger the Section 20 consultation process before a contract is placed. We provide the specification and pricing you need for that consultation.
EWI for flats and blocks prices in Gwynedd
| Item | Guide price | Notes |
|---|---|---|
| Mineral wool system on a low-rise block | £110–£190 per m²0% VAT | Priced on survey |
| Scaffold and access | Priced per building | Includes licences where needed |
| Specification and pricing pack for consultation | Included with quote |
Confirmed by a fixed written quote after survey. 0% VAT: installing insulation in a home is zero-rated until 31 March 2027, so these figures are the total; 5% applies from 1 April 2027.
From enquiry to finished wall
Enquiry
Send your postcode and a few details.
Measured survey
Walls, damp, eaves, cills and services recorded.
Written price
A fixed price with the specification attached.
Work and handover
Installed, inspected and documents handed over.
Flats and blocks in Gwynedd: questions
Can one flat have external wall insulation on its own?
Rarely. The outside walls are usually owned by the freeholder, the result would look patchy, and planning is unlikely. Whole-building schemes are the norm.
Who pays for EWI on a leasehold block?
In England and Wales, usually the leaseholders through the service charge, depending on the lease, and the landlord must follow the Section 20 consultation process for major works.
Do flats need planning permission for EWI?
Yes. Permitted development rights for external alterations apply to houses, not flats or maisonettes, so an application is needed.
Do you cover all of Gwynedd?
Yes. We survey and quote EWI for flats and blocks across Gwynedd, including Bangor (Gwynedd), Holyhead, Caernarfon, Llangefni.
Do I need planning permission in Wales?
Permitted development rules for houses in Wales are similar to England's: a similar-appearance finish on a house is often permitted, while conservation areas, National Parks, Areas of Outstanding Natural Beauty, flats, commercial buildings and listed buildings need permission or consent. We check your address before quoting.