For Victorian, Edwardian & inter-war homes
A millimetres-thin insulation coating developed for solid-wall homes where insulation boards and cladding aren't viable.
Solid walls are often the biggest weakness left. No cavity. No insulation.
Heat Halo changes how those walls perform — so rooms warm faster and stay warmer for longer.
The Problem
If your home was built before 1939, the chances are your walls are solid — no cavity, no insulation. That's the largest unsolved problem in your house.
It shows up as cold walls even with the heating on, condensation in corners, black mould behind furniture, an EPC stuck in D–F, and money spent heating air that escapes straight through the brick.
The traditional insulation solutions don't help much.
Changes how your home looks — most Planning Officers won't allow it on a period property.
Eat 3–11 m² of floor space, require removing skirting, moving sockets, rebuilding window reveals, and moving the family out for weeks.
Sound easy but rarely deliver measurable results. That's why they have a well-earned reputation problem.
So most homeowners do nothing. And pay for it every winter.
Heat Halo can help improve your EPC rating — increasingly important for property value and future saleability.
Independent Performance Evidence
Heat Halo has been independently evaluated under BS EN ISO 9869 using treated and untreated rooms on the same solid-wall property.
Because Heat Halo adds thermal resistance rather than delivering a fixed percentage outcome, colder solid walls that lose more heat to begin with typically benefit more than the independently tested baseline wall.
See the independent test methodology →
Independently tested under BS EN ISO 9869 in a live occupied property. See the full methodology →
A quick suitability check tells you if Heat Halo is the right answer.
How it works
Heat Halo is a professionally installed, spray-applied thermal coating — just 2 millimetres thick, finished with a sprayed plaster skim and emulsion. Installed by trained specialist contractors with documented quality control on every surface.
The finished wall takes pictures, shelves, radiators and paint exactly like any other wall in your home.
It is also vapour-permeable, meaning the wall can still breathe — solid-wall homes were designed that way for a reason. The wrong insulation can trap moisture in the brick, leading to damp, black mould, and long-term damage to your home.
Heat Halo is not a retail thermal paint. It is a professionally installed internal insulation system with controlled application, finishing and documented QA on every surface.
How much room does insulation use?
Why cold walls cause mould — and how Heat Halo solves it
What it costs
Larger period homes typically fall between £24,000–£35,000+. Every quote is fixed after a survey — no estimates, no surprise add-ons partway through the job.
| Property size | Typical scope | Indicative range |
|---|---|---|
| 1–2 bed flat or cottage | Key rooms or full internal treatment | £10,000–£16,000 |
| 2–3 bed solid-wall house | Full internal wall treatment, all rooms | £16,000–£24,000 |
| 4+ bed period property | Larger floor area, more wall surface | £24,000–£35,000+ |
2–3 days. Rooms protected, surfaces prepared.
2–4 days. Professional spray by trained installers.
2–3 days. Conventional skim applied over the system.
2–3 days. White emulsion, skirting and making good.
Included in every install: all preparation and masking, spray application, plaster skim, redecoration to white emulsion, minor making good to woodwork, and per-surface QA documentation.
For a full cost breakdown — what affects the price, how it compares to boards and external insulation, and the replastering comparison — see the Cost Guide →
Is your home a fit?
Homes built before around 1920 are typically solid-wall construction. If your external walls feel cold to the touch or are relatively thin compared with modern cavity walls, Heat Halo may be a strong fit.
Common questions
No. Heat Halo is an installed, multi-coat thermal system applied by trained specialist contractors and finished with a plaster skim.
The base material uses ceramic microspheres, but the performance claim belongs to the installed system — the assessment, masking, application standard, controlled film thickness, and skim finish. It is not a DIY thermal paint and isn't pretending to be one.
The opposite. Heat Halo is vapour-permeable, so moisture can move through the wall the way it always has.
Solid-wall homes are designed to let moisture pass through. The wrong insulation traps it in the brick, leading to damp and black mould.
Heat Halo doesn't seal the wall — it allows it to breathe.
Almost never. We work through the home in stages so you always have unaffected rooms to use. Most installs are 2–3 weeks end to end. We'll walk through the programme with you at survey stage so you know exactly what to expect.
Yes — it contributes toward improving your EPC rating.
In solid-wall homes where loft insulation and modern windows are already in place, the walls are often the last major source of heat loss. Improving their performance can support a move from D to C.
The exact impact depends on the property and the assessor's methodology.
The independently measured figure is 16%, tested over 18 days. The improvement is fixed in thermal resistance terms, so the worse your wall's starting performance, the greater the percentage gain — typical solid-walls with a U-value of 2.0 W/m²K can expect around 25%. We'll give you a more specific estimate after surveying your property.
Every Heat Halo installation is covered by a 10-year installation-backed system guarantee, covering defects in the installed coating system and associated plaster finish when installed by approved Heat Halo contractors and used as specified.
The guarantee applies to the system as professionally installed — which is part of why Heat Halo is only available through approved installation, never as a DIY product.
Typical projects range from approximately £10,000 for a 1–2 bed flat or cottage to £35,000 for a larger period property. A typical 2–3 bed solid-wall house falls in the £16,000–£24,000 range. Every quote is fixed after a survey — no estimates, no surprise add-ons.
More questions? View our full FAQ →
Delivered by Heat Halo — specialists in solid-wall thermal retrofit
Sixty-second suitability check. We come back within two working days.
Or speak to us directly: surveys@heathalo.uk
