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Wrap the house. Change the bills.
Solid walls insulated from outside and finished in render or brick slip, to PAS 2035, across Chertsey and Surrey.
What goes on the wall
It is a system, not a product. Every layer has a job and they are specified together.
The wall is prepared
Render checked, pointing made good, and anything wet dealt with. Fixings, sills, downpipes and meter boxes come off or get extended.
Boards go on
Insulation board bonded and mechanically fixed to the wall, cut round openings, with beads at every edge and reveal so the detail is continuous.
Mesh and basecoat
A reinforcing mesh embedded in basecoat over the whole face. This is what stops the finish cracking as the building moves.
The finish
Silicone or mineral render, or brick slip where matching the original matters. Colour chosen before the job starts, not on the day.
The details that decide it
The system is straightforward. Whether the job works is decided at the edges.
- Eaves and verges
- The roof has to overhang the new, thicker wall. Sometimes that means extending the eaves, and that is priced in rather than discovered.
- Window and door reveals
- The thinnest, most exposed part of the whole system. Reveals get their own thinner board, and it is where cold bridges appear if they are skipped.
- Damp proof course
- Insulation must stop above the DPC or it bridges it and carries ground moisture up into the wall.
- Ventilation and flues
- Air bricks get sleeved through, and boiler and stove flues extended to suit the new wall thickness.
Outside, inside, or neither?
Solid wall insulation is one decision with three answers. Which one is right depends on the wall.
What is the wall like?
Does the outside of the house matter to you?
Insulate from the outside
Boards fixed to the outside face and rendered over. The warm side of the wall stays inside the insulation, which is the thermally correct way round.
Insulate from the outside
Boards fixed to the outside face and rendered over. The warm side of the wall stays inside the insulation, which is the thermally correct way round.
- No room lost inside, and you can live there throughout
- Covers the whole face, so cold bridges are dealt with properly
- The house looks different afterwards, which is the trade
- Needs eaves, sills and downpipes extending
- Not usually possible on a listed building or in a conservation area
Insulate from the inside
Insulated board or a studded system on the inside face, room by room, with the outside of the house untouched.
- The exterior is unchanged, so listed and conservation properties can have it
- Done room by room, so you can spread it over time
- You lose some room depth, and skirtings, sockets and radiators come off
- Cold bridges at floors and party walls need designing around
- Rooms are out of use while they are done
Fill the gap you already have
If a borescope finds a clean, dry cavity, filling it is faster and cheaper than either of the above.
- Around a day, entirely from outside
- No change to the appearance and no room lost
- After the loft, the biggest single saving in the house
- Only possible where a suitable cavity actually exists
- The survey establishes that before anything is quoted
Whichever the answers point at, the survey decides it properly. Solid wall work is the measure most worth getting right first time.
This is the measure most worth certifying.
Solid wall insulation done badly causes more damage than it prevents — trapped moisture, cracked render, cold bridges at the reveals. Done to PAS 2035 and PAS 2030 with the details drawn, it does exactly what it is supposed to.
That is why funded schemes require the standard, and why we hold it rather than subcontracting the certified part to somebody else.
PAS 2035 covers the assessment and design; PAS 2030 covers the installation. We are certified to both, under TrustMark licence 3288118.
How the job runs
A look at the walls
Construction, condition, the eaves, the reveals and what is fixed to the outside of the house.
Assessment and design
On a funded job this is a formal PAS 2035 assessment. On a private one it is the same work, less paperwork.
Approvals
Planning where it applies, and building control notification. We handle both.
Installation
Scaffold, preparation, boards, mesh, basecoat and finish, with drying time between coats.
Handover
Certification, the guarantee and the system documentation for the render you have.
After the work is signed off
A rendered wall is a finish, and finishes get looked after.
Your paperwork, on the day
PAS 2030 installation certificate, the system manufacturer documentation and, on a funded job, the full assessment and design record.
A two year guarantee
In writing, transferable if you sell, and insurance-backed, alongside the render system's own warranty.
It moves your EPC further than anything else
Wall construction is the heaviest weighted element an assessor records.
One number, and the same team
Render can be repaired and colour matched. You ring the people who applied it.
Two things people ask about next
Both have a page of their own.
The questions we get asked most
Will it change how the house looks?
Yes. That is the trade-off. Render comes in a range of finishes and colours, and brick slip can match the original closely, but the elevation will not be identical to what is there now.
Does external wall insulation need planning permission?
Often yes, because it alters the external appearance. Listed buildings and conservation areas almost always. We establish what applies before you commit.
How much room does it take up outside?
The system adds thickness to the wall, which is why eaves, sills and downpipes have to be extended. Boundaries and pavements matter too, and we check them.
Can I stay in the house?
Yes. All the work is outside, so apart from scaffolding and noise the house stays usable throughout.
How long does external wall insulation take?
Two to four weeks for a typical house, and weather affects it, because render needs drying time between coats.
Is there VAT on external wall insulation?
No. Insulation is zero-rated until 31 March 2027.
Could a scheme pay for external wall insulation?
Solid wall insulation is one of the measures funded schemes are designed around. Eligibility depends on the household and the property, and we check it.
Often worth doing at the same time
Same team, same survey, one visit where it makes sense.
Book a free survey for external wall insulation
Tell us about the property and we will come and look at it. No charge, and the figures come in writing afterwards.
- A proper survey, and the figures in writing
- Any grant you qualify for, applied for by us
- No charge, whether or not you go ahead
- Weekdays 8am to 5pm, on 01932 550828
We will tell you which of the three it is.
Outside, inside, or a cavity you did not know you had. The survey settles it, and it is free.