External Wall Insulation & Rendering
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External Wall Insulation & Rendering

Solid wall insulation for older homes, fitted to the outside of the house and finished with a new render. Our own installers cut the heat lost through your walls, protect the brickwork from the weather and give the exterior a clean, modern finish.

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External Wall Insulation & Rendering

Finance options available using

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Sound familiar?

Solid walls that let the heat straight out, and the damp in?

Older homes with solid walls have no cavity to fill, so they lose heat straight through the brickwork. In an uninsulated home, around a third of the heat escapes through the walls, and no amount of turning up the thermostat fixes a wall that can't hold it.

External wall insulation wraps the outside of the house in an insulated, rendered layer. Done badly, it traps moisture. Done properly, it's one of the biggest single improvements an older home can have, and your rooms stay exactly the same size.

Assess my walls
  • Cold, heat-hungry walls

    Solid brick that loses heat almost as fast as your heating can put it in.

  • Damp and mould

    Cold inside wall surfaces where condensation settles and black mould follows, often behind furniture and in corners.

  • Tired, weathered exterior

    Crumbling render, blown patches or worn brickwork that needs attention anyway.

  • No room to insulate inside

    Rooms too small to give up space to internal wall insulation.

What's Included

  • Fitted by our own external wall insulation installers, no subcontractors
  • External wall insulation and render as one complete system
  • Weatherproof render finish in a choice of colours and textures
  • Sills, eaves, pipework and openings detailed to keep moisture out

External Wall Insulation for Solid Wall Homes

Homes built before the 1920s usually have solid walls instead of a cavity, and they're common across older housing in the West Midlands and Wales. Without a cavity to fill, the only way to insulate those walls is from the inside or the outside. External wall insulation does it from the outside: we fix insulation boards to the walls, reinforce them with mesh and finish the whole house in a new render.

Because the work is all on the outside, you keep every inch of room space and stay in your home throughout. The new render also acts as a weatherproof layer, protecting the brickwork from rain and frost, so external wall insulation and render tackle heat loss, damp and a tired exterior in one project.External wall insulation is also a sensible first step before a heat pump. A home that holds its heat needs a smaller system, so if you're planning both, it's worth pairing it with our loft insulation and air source heat pump installation services.

  • Wall construction and condition checked before we quote
  • Damp and cracked render identified and put right first
  • Insulation thickness chosen to suit your walls
  • Neat finishing at windows, doors, eaves and ground level
External Wall Insulation — after
External Wall Insulation — before

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Case study

External Wall Insulation

See the before and after of a full external wall insulation upgrade on an older property, where the solid walls were insulated and finished with a new render by our own installers.

The external walls of this older property were insulated from the outside and finished with a new render, cutting the heat lost through the building fabric and making the rooms far easier to keep warm.

Because the insulation is fixed to the outside of the walls, no room lost any floor space and the household stayed in the property throughout. The render then works as a weatherproof layer over the top, protecting the brickwork from rain and frost.

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Projects Completed

Solar, heat pump and storage installs delivered across residential and commercial properties.

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Years Combined Experience

An accredited team with decades of hands-on energy and construction work behind it.

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Industry Accreditations

Independently audited by MCS, TrustMark, Gas Safe and five other industry bodies.

Client Stories

Trusted By Homeowners And Businesses Alike

See how our renewable energy solutions are helping customers reduce costs, increase efficiency, and gain greater energy independence.

Amjid H.

Amjid H.

Home Owner

I got my insulation done by greentek they were fantastic from the start. On the way we had one two problems from the contractors but greentek took care of it! Kept me informed and solved the issues. They communicated consistently and kept me in the loop.

Review from Google

★★★★★

Luki

Luki

Business Owner

We required an urgent new boiler installation due to the old one breaking down and being unrepairable. Greentek Energy supplied and fitted a new one at very short notice so our tenants could have heating and hot water again. We are very grateful to Greentek Energy and would recommend them highly.

Review from Google

★★★★★

Ian B.

Ian B.

Home Owner

Part of the Ecobility company. the people at Greentek know their stuff. Got a quote in just under 20 minutes where others insisted on coming around the house. They were cheaper too!

Review from Google

★★★★★

Omer M.

Omer M.

Home Owner

Quick and efficient service.

Review from Google

★★★★★

Amjid H.

Amjid H.

Home Owner

I got my insulation done by greentek they were fantastic from the start. On the way we had one two problems from the contractors but greentek took care of it! Kept me informed and solved the issues. They communicated consistently and kept me in the loop.

Review from Google

★★★★★

Luki

Luki

Business Owner

We required an urgent new boiler installation due to the old one breaking down and being unrepairable. Greentek Energy supplied and fitted a new one at very short notice so our tenants could have heating and hot water again. We are very grateful to Greentek Energy and would recommend them highly.

Review from Google

★★★★★

Ian B.

Ian B.

Home Owner

Part of the Ecobility company. the people at Greentek know their stuff. Got a quote in just under 20 minutes where others insisted on coming around the house. They were cheaper too!

Review from Google

★★★★★

Omer M.

Omer M.

Home Owner

Quick and efficient service.

Review from Google

★★★★★

Our Process

Four Steps.
Zero Surprises.

From the first call to the final handover, a clear, transparent process designed to deliver solar, home improvement, and renovation work with zero hassle.

STEP 1

Free Survey

Book online or call. A Greentek specialist visits your property to assess your solar, heating, insulation, or renovation needs.

STEP 2

Custom Quote

Get a clear, fixed-price quote with material and brand options, and an honest timeline, no hidden fees.

STEP 3

Expert Installation

Our in-house accredited team carries out the work, solar, heat pump, insulation, or renovation, no subcontractors passing the job around.

STEP 4

Handover & Warranty

We walk you through everything on completion, clean up after ourselves, and hand over your written warranty.

Fully Accredited & Certified.

  • MCS Certified
  • TrustMark Government Endorsed Quality
  • Gas Safe Register
  • HIES accredited
  • Amtivo certified
  • SWIGA member
  • Qualitymark Protection accredited
  • British Assessment Bureau certified

What it costs

What External Wall Insulation Costs

External wall insulation is priced by the wall rather than by the house, so two homes of the same size can cost very different amounts. These four things set your price.

  • Wall area

    The total area to be insulated and rendered, measured properly at the survey.

  • Access and scaffolding

    Height, ground conditions and how much scaffolding the property needs.

  • Insulation thickness

    How thick the insulation needs to be for your walls to reach the performance we're aiming for.

  • Render and detailing

    The finish you choose, plus sills, eaves and openings, which is where this work is won or lost.

Every quote includes

  • A free site survey, with no obligation to go ahead
  • A fixed price agreed in writing before any work starts
  • Materials, labour and making good, in one price
  • Our own team throughout — no subcontractors marking the job up
  • A written workmanship warranty on completion

We don't quote over the phone from a postcode — the survey is what makes the price fixed rather than an estimate that moves. Finance is available through Ideal4Finance, subject to status.

Get a fixed-price quote

Frequently asked questions

How much does external wall insulation cost?+
It depends on the wall area, access and scaffolding, the insulation thickness, the render finish, and details such as windowsills and pipework. We survey the property and give a fixed-price quote.
Is external wall insulation right for my house?+
It's most effective on solid-wall homes with no cavity to fill, typically older properties. We check the wall construction, condition and any damp first, and tell you honestly if another option suits better.
Do I need planning permission for external wall insulation?+
It depends on the property and on how much the appearance changes. Front elevations, conservation areas and listed buildings often need permission, and we check what applies before work starts.
Will external wall insulation cause damp?+
Not when it's designed and installed properly. The system and render are chosen for the wall, and details at windows, eaves and ground level are finished carefully so moisture can't get trapped behind it.
How long does external wall insulation take?+
A typical house takes a few weeks, depending on size, weather and scaffolding. You stay in the home throughout, because the work is all on the outside.
Can I spread the cost of external wall insulation?+
Yes. We offer finance options through Ideal4Finance, subject to status.

Free Quote

Get a Free External Wall Insulation Quote

Tell us about your external wall insulation project and we'll come back within one business day with a straight answer, a plan and a real quote.

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