External Wall Insulation

We install external wall insulation (EWI) to make your property greener, more thermally efficient and cheaper to run. Our expert team works with homeowners and landlords to boost green credentials and cut energy bills.

TrustMark-verified EWI installers

We are TrustMark verified installers of EWI. TrustMark is a Government Endorsed Quality Scheme – when you choose us, you know you are choosing a business that has been thoroughly vetted. Plus, you have additional consumer protection because we are a TrustMark Registered Business.

To become a TrustMark Registered Business, we have had to prove we comply with the three cornerstones of quality:

  • Technical competence
  • Good customer service
  • Good trading practices

Certifications and approvals: quality products, efficient insulation

All our external wall insulation has British Board of Agrément (BBA) certification, indicating that it’s high quality and reliable. It is automatically acceptable to local councils, building authorities and insurance companies due to this certification.

As members of a competent person’s scheme, we have the experience and authority to sign off our own work without Building Control involvement. This saves you time and money as you won’t need to wait for your local council Building Control Officer to inspect your property, or pay to hire an approved inspector privately.

Get your quote for EWI

Just fill in our form and we’ll be in touch to arrange a full, free EWI quote.

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What is external wall insulation?

External wall insulation is a type of coating that’s applied to the exterior walls of a property, primarily to improve energy efficiency and heat retention. It also improves a property’s appearance, creating a neat, attractive finish, with various colourways available.

We use external wall insulation products of the highest quality, from industry-leading brands, including:

  • Baumit
  • K Rend
  • Sto
  • EWI Pro
  • Parex

We are approved installers of their systems, so with the quality of their external insulation and the expert workmanship of our team, you will be able to enjoy better performance from your property for many years to come.

Our wall insulation systems are finished off with a layer of render in the colour of your choice, achieving an attractive, modern appearance. We can also apply render to the walls that haven’t been insulated, creating a consistent finish.

The benefits of external wall insulation

External wall insulation offers a whole host of benefits, including:

  • Versatility. EWI is compatible with a variety of surfaces, including concrete, masonry and render.
  • Quality. We use fully certified external wall insulation systems from leading suppliers in the field.
  • Heat retention. 90mm insulation can achieve U-values of 0.3W/m²K for existing solid walls, which will be approved by Building Control.
  • Soundproofing. An EWI system helps to make your property more soundproof and reduce external noise.
  • Excellent aesthetics. EWI systems are completed with a layer of render for a stunning, premium finish.
  • Cost effectiveness. EWI will help to cut energy bills by making properties more efficient.

A greener way to insulate your property

Well-insulated properties require less energy to heat them, helping to reduce emissions. The Committee on Climate Change advises that existing homes should be retrofitted to both reduce emissions, and make sure they are properly prepared for the impact of climate change. EWI helps you make greener home improvements in line with these recommendations.

Commercial installations

We can also install external wall insulation and vented render systems for commercial clients. We partner closely with builders, architects and tradespeople – learn more about our commercial EWI services.

Commercial EWI installation

External wall insulation installation process

We make sure the EWI installation process is simple and straightforward for you, and that you know exactly what to expect. Here’s what happens:

  • Every job is specified by the manufacture, be it Baumit, K Rend or Sto.
  • A basecoat adhesive is applied to stick the insulation to the wall.
  • Expanded polystyrene (EPS) insulation is installed.
  • Mechanical fixings are installed – 6/m².
  • A meshed render basecoat is applied.
  • The topcoat is applied in a colour of your choice.

We use mineral wool instead of EPS if the installation is over two floors or more. We use the appropriate materials for your home’s safety.


See some of our previous projects in our gallery.

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Contact AMJ Contracts

We are here to offer help and advice. If you want to arrange for your free, no obligation quote, call 020 3633 1074 or email .