Stay Warm. Save Money. Live Better.
Home insulation contractors
for London & the South-East
Save money on energy bills and live better in a warmer home — expert insulation for houses & businesses across London and South-East England.
What we install
Insulation work we do with our own team
Four measures make up almost all of our work. Each page below has the systems we fit, how the job runs, and real prices from our quote book of 454 priced quotes.
External wall insulation installers
Insulation board and render fixed to the outside of solid walls. The biggest single saving for most pre-1930s and 1930s houses, with no loss of room space.
Typical job £11,880 to £23,118 · median £17,300 from 170 priced quotes
External wall insulation: systems, process and prices
Internal wall insulation installers
SWIP and breathable systems fitted room by room on the inside. The answer for conservation areas, listed homes, flats and period fronts that must not change.
Typical job £3,828 to £9,701 · median £5,550 from 108 priced quotes
Internal wall insulation: systems, process and prices
Loft and attic insulation
Top-ups to 270mm, raised boarding for storage, and rafter systems for converted lofts and rooms in the roof.
Typical job £2,830 to £5,854 · median £3,825 from 117 priced quotes
Loft and roof insulation: systems, process and prices
Suspended floor insulation
Insulation between the joists of suspended timber floors, with the sub-floor air flow kept open. Stops the cold draught at skirting level.
Typical job £2,927 to £6,705 · median £4,320 from 59 priced quotes
Floor insulation: systems, process and pricesAlso on request
Want to know what a job like yours costs first? See what insulation really costs in London, from real quotes and finished jobs.
Our work
A selection of completed insulation projects across London and South-East England.
270mm Mineral Wool & Boarding
Loft insulation in Uxbridge
90mm EPS External Wall Insulation
External wall insulation in Harrow
Brick Slips
Brick slip installation instead of render
Rockwool Insulation
Mid-Install in Surrey
Suspended Floor Insulation
Mineral Wool in Dulwich
Internal Wall Insulation using SWIP IWI
SWIP IWI mid install in Croydon
External Wall Insulation
Finished Install in SW London
Internal Wall Insulation
Internal wall Insulation in progress
Customer reviews
What our customers say
SWI undertook both Internal and External insulation, and even managed to build a porch for us. The work was carried out quickly, efficiently, and to a very high standard. The team were polite, communication was fantastic throughout, and they always tidied up at the end of each day. I wouldn’t hesitate to recommend this company.
Phil Wilcock
KT2 5NW · April 2026
“Very professional, yet very kind. External insulation is only worth it if carried out properly and professionally — and that is exactly what SWI provides. Their workers are very polite and pleasant to have around.”
Marie Dominique Scholtes
TW12 2TJ · April 2026
“I could not recommend Stay Warm Insulation enough. They delivered to a very high standard and went above and beyond to fulfil my requests.”
Lukasz Zielinski
WD19 4FJ · February 2026
Who we are
About Stay Warm Insulation
Stay Warm Insulation Ltd was founded in 2018 by a team of building professionals with over 20 years of hands-on experience, driven by the growing need for high-quality, properly installed insulation across London and the South East.
We focus exclusively on insulation. That means External Wall, Internal Wall, Loft, Roof and Floor — nothing else. Every project gets the same level of care, whether it’s a single flat or a large commercial building.
What sets us apart is that we handle every aspect of the job from start to finish. Our team is fully qualified across all related trades — alongside the insulation itself, we take care of any building work, plastering, plumbing adjustments, and electrical work required. One team, one point of contact, no subcontracting surprises.
We hold PAS 2030:2023 certification and are TrustMark approved — meeting the government’s required standards for quality and safety on every insulation project we deliver.
Based in Hounslow, we cover all of London and South-East England. Over 500 installations completed, rated 9.87/10 on Checkatrade from 122 verified reviews — many of our customers know us simply as StayWarm.
Got questions?
Frequently asked
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What happens next
- 1We call you back at your preferred time
- 2We discuss your property and answer any questions
- 3We outline the best options and costs clearly
Ready to Transform Your Property?
Whether you want to explore your insulation options, modernise or sustainably improve your property — get in touch today
Get your expert quotePAS 2030:2023 & TrustMark Certified • 20+ Years Experience • London & South-East England