Group D · Floors, basements and underfloor heating
Basement and cellar insulation
Insulating basement walls and floors with tanking or cavity drain membranes.
Priced after survey
Basement and cellar insulation
Every job like this is different, so we measure first and give you a fixed written quote. The price depends on:
- The area and access
- What's there now and its condition
- The system and finish you choose
No obligation — your survey confirms what suits and what it costs.
- Best for
- Basement conversions, cellars
- Guarantee or standard
- BS 8102 waterproofing
- Time on site
- Programmed after survey, as part of the basement or cellar works.
- Typical price
- Priced after survey
What it is
What is basement and cellar insulation?
Insulating basement walls and floors with tanking or cavity drain membranes.
Best for: Basement conversions, cellars.
Who it suits
Which homes is basement and cellar insulation suitable for?
Is my home suitable?
Pick your property type for a straight answer on basement and cellar insulation.
Guidance only — every home is different, and a survey confirms what suits yours.
Houses
- Detached house
- Semi-detached house
- End-of-terrace
- Mid-terrace
- Townhouse
- Mews house and cottage
- Detached bungalow
- Semi and terraced bungalow
- Chalet and dormer bungalow
- Period home
- 1930s home
- Post-war and ex-council house
- Non-traditional / system-built
- Listed building or conservation area
- Farmhouse, barn conversion or rural home
- New build or self-build
Flats and blocks of flats
Commercial and public buildings
Usually suitable Depends — a survey confirms
Not usually suitable for 1 property type
- Park and mobile home — Park and mobile homes need specialist systems, which we arrange through a partner rather than standard measures.
Materials and brands
What we use
Insulating walls and floors with tanking or cavity drain membranes.
Insulation brands we work with
- Knauf Insulation (Earthwool, Supafil blown)
- Rockwool
- Superglass
- Isover
- Kingspan
- Celotex
- Recticel
- Xtratherm
- Steico wood-fibre
- YBS and Actis multifoil
The exact system and brand for your home are confirmed in your written quote.
Heat, bills and EPC
What it does for your heat loss, bills and EPC
Suspended timber floors lose heat through the boards and let cold air in through the gaps; solid floors conduct heat into the ground. Insulating the floor and sealing the gaps lowers the floor's U-value and cuts draughts, so rooms feel warmer at the same thermostat setting, and the EPC usually improves.
See the EPC points and savings for your home in the EPC plannerU-value before and after, typical heat and bill saving, and EPC points — worked out for your property.Price
How much does basement and cellar insulation cost?
Priced after survey
Jobs like this vary too much for a fair online price, so we measure first and give you a fixed written quote — with no obligation.VAT on this work
Insulation installed in homes in Great Britain is zero-rated for VAT until 31 March 2027. Other parts of a job like this — such as a new roof covering, structural work or waterproofing — may be standard-rated. Your quote shows the split.What to expect
Time on site, disruption and approvals
Time on site
Programmed after survey, as part of the basement or cellar works.
Disruption
Contained to the basement, which is out of use while we work.
Planning and building control
Waterproofing designed to BS 8102. Turning a cellar into habitable space needs Building Regulations approval, and sometimes planning permission.
Guarantee and standard
BS 8102 waterproofing. The guarantee and certification for your job are confirmed in writing in your quote.
60-second grant check
Could a grant help pay for it?
Grant eligibility checker
About 60 seconds · plain results: likely, possibly or not eligible
Before we start
What type of property is it?
Questions
Basement and cellar insulation: your questions answered
Can you insulate a damp basement?
Only once the damp is controlled. Basement insulation is installed with a waterproofing system — tanking or a cavity drain membrane — designed to BS 8102.
Do you insulate basement walls and floors?
Both, depending on the space and how it will be used.
Is a basement conversion building work?
Turning a cellar into habitable space needs Building Regulations approval, and in some cases planning permission.
Group D
More in floors, basements and underfloor heating
Suspended timber floor insulation
Mineral wool or rigid board between the joists with an airtight membrane.
Underfloor insulation from the void
Insulation fitted from below through a crawl space, without lifting floorboards.
Solid floor insulation
PIR or XPS boards over the slab with a new screed or floating floor.
Insulated floor screed
Insulation plus screed, ready for underfloor heating.
Underfloor heating insulation
Insulation boards under wet or electric UFH so heat goes up, not into the ground.
Floors over garages and open space
Insulating floors over unheated garages, passages, undercrofts and overhangs.
Begin your project
Ready to talk about basement and cellar insulation?
Tell us about your home and we'll arrange a survey, then a fixed written quote — no obligation.