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External Wall Insulation

Fully Qualified Contractors

Ralph Plastering is certified by British Gypsum, holds accreditations with SMAS and Worksafe Contractor and is recommended by Weber.

Interior & Exterior Specialists

Our team specialise in external wall insulation, rendering, drylining and plastering for both residential and commercial projects.

5 Star Customer Feedback

Over 100 five-star reviews received from our customers across London and Surrey. We will do everything we can to maintain our reputation.


Our company has over 20 years of industry experience and is able to deliver expert advice and consultation for your project.

External Wall Insulation London

EWI installer providing all aspects of exterior insulation

Ralph Plastering provide external wall insulation London and Surrey and have over 20 years experience installing exterior insulation systems. We trained Weber Recommended Contractors, EWI Pro Recommended Installers, offer 10 year product warranties and workmanship guarantees to ensure customers have total peace of mind.

Having external wall insulation installed (EWI) is a highly effective way of insulating your property. Exterior insulation is suitable for houses without a cavity or solid wall construction and is designed to make your significantly home warmer. Our EWI systems can be finished and covered with either lightweight monocouche or silicone rendering.

If you are looking London based external wall insulation specialists to help install an exterior insulation system, then get in touch with us to request a free quote and consultation today. From here we can book a date for a free survey and then discuss next steps. Click the make an enquiry button below to get started on your EWI project today!

Looking For An External Wall Insulation Company? Get A Free Quote Today!

Transform Your Home With External Wall Insulation

External Wall Insulation London - EWI Installation - Ralph Plastering

Is external wall insulation worth it?

We are often asked whether or not getting external wall insulation installed is worth it in terms of return on investment. We believe it is! Up to 33% of heat is lost through your walls. This causes a constant chill leading people to turn up their heating fully which costs a significant amount of money.

Like your windows, when you heat a cold room with freezing walls it forms condensation on the exterior wall. The warm air hits the cold walls which creates moisture. Due to the constant cooling and heating, moisture builds up causing damp and mould, which can lead to potentially high repair costs.

External walls are cold because they are the only barrier between the room and outside. External insulation is easier to install compared to internal wall insulation because it doesn’t involve the hassle of removing skirting boards, flooring, re-plastering, re-painting and decorating, removing radiators, etc. 

Stay Warmer In The Winter & Cooler In The Summer

Reduce Your Heating Bills & Save More Money

No Need To Use Up Any Internal Floor Space

Reduce Your Household Carbon Footprint

Improve Your Property's Energy Efficiency Rating

Improve Your Homes External Aesthetics

Increase The Sale Value Of Your Property

Reduce Damp & Mould Caused By Condensation

Our Most Recent External Wall Insulation Projects

Dale Wood Road

External Wall Insulation, Rendering

Camberley Theatre

External Wall Insulation, Rendering

The Ridge

External Wall Insulation, Rendering

DPR Motors

External Wall Insulation, Rendering

Our External Wall Insulation Process

Here's a quick overview of how our EWI systems work...

All work is carried out by fully qualified EWI experts and will be to the highest possible standards and generally includes the following items:

  1. Scaffolding erected to provide easy and safe access.
  2. Protect windows, guttering and other external fixtures.
  3. Install EPS boarding and prepare all areas requiring EWI.
  4. Base coat and mesh application.
  5. Finish with customers choice of appropriate renders.
  6. Waste disposal, cleaning and dismantling scaffold.

Our team of EWI installers in London have over 20 years of experience and come highly recommended by previous customers who have commented on the care and respect our team had whilst working on their home. We will do everything we can to ensure your experience is that of total satisfaction.

External Wall Insulation London - EWI Installation - Ralph Plastering

Our external wall insulation products:

Here are three of our most popular external insulation products that we use on most types of home external wall insulation projects:

  • Expanded Polystyrene (EPS) – this is a rigid and lightweight foam that offers excellent thermal insulation. It’s moisture-resistant and quick to install. EPS is suitable for most type of properties which makes it a common choice of external wall insulation system.
  • Mineral Wool – this delivers an excellent level of thermal and acoustic insulation. It’s fire resistant, breathable and an eco-friendly material that’s a great option for all type of properties.
  • Phenolic Foam – this a high performance type of external insulation that delivers a maximum thermal efficiency in an ultra-thin layer. It’s a fire and moisture resistant material which makes it a great choice of external insulation for smaller properties with limited space.

Different types of rendering finishes for EWI:

Here are three of the most popular rendering products we use as the final finish on our external wall insulation projects:

  • Monocouche Render – this is an advanced, one-base coat render that’s pre-coloured and requires no painting. Monocouche is low maintenance, breathable, weather resistant and has hundreds of colours and textures to choose from, which makes it much easy when it comes to finding the desired look for your home.
  • Acrylic Render – this is a flexible, water-resistant option, premixed with acrylic resins. Acrylic render can be applied to various substrates and has great adhesion properties which makes it strong and crack-resistant. It’s available in hundreds of colours and textures making it a popular choice with our customers.
  • Silicone Render – this is a flexible, water resistant, breathable, mould resistant, low-maintenance and long lasting render material.

External Wall Insulation Prices

There are several factors that will determine your external wall insulation quote. For example, whether you have solid or empty cavity walls, the type of external insulation components required, how much scaffolding is needed, what type of rendering finish you choose (silicone or monocouche), how many square metres, etc.

Approximately you can expect a professional and fully trained EWI specialist to charge between £150 to £200 per m2 (including labour and materials). You DO NOT want to go cheap on exterior insulation because a poorly installed system will lead to you having to pay even more to fix it. Ripping off the old and starting again is costly!

It is worth considering other potential costs including scaffolding and alterations to window sills, guttering and down pipes and verge trims to accommodate the additional 90-120mm for the render. Please click here to see our rendering prices and here to read our full guide on how much does external wall insulation cost.

External Wall Insulation London - EWI Installation - Ralph Plastering

Are you looking to install External Wall Insulation in London or Surrey?

Ralph Plastering is a fully approved residential and commercial external wall insulation company in London and Surrey with EWI Pro Recommended Installers that have over 20 years of experience.