What is External Wall Insulation (EWI)?

External wall insulation (EWI) offers a solution to homes constructed with solid walls to become more thermally efficient. It does so by mitigating the amount of heat lost through the walls of a building, which is estimated to be around 35%. External Wall Insulation is the application of thermally insulating materials (e.g. EPS boards) and a finished system (e.g. render) to the outside face of the external walls of an existing building to improve its thermal performance. A good analogy is that of placing a tea cosy around a building.

EWI is an extremely cost-effective way of insulating the walls of a building, the reason being EWI ensures the entire surface is fully insulated resulting in the elimination of any cold or thermal bridging. (Thermal bridging is an area of a building which has significantly higher heat transfer than the surrounding areas. This is often caused by a break in insulation, less insulation or the insulation is penetrated by an element with a higher thermal conductivity).

A layer of insulation is fixed to an existing wall using adhesive and fixing anchors and then finished with a weatherproof system such as render, pebbledash or alternatively cladding to protect the insulation and keep the system watertight.

An EWI solution can be engineered to suit practically any type of building design and construction, with established methods adopted for non–traditional housing, standard specifications of solid walls and more bespoke solutions for new builds and many non-domestic situations.

We provide a range of EWI solutions (single or multi storey, solid wall, non-traditional or cavity construction), which feature a variety of insulation materials including Expanded Polystyrene (EPS), Stone Wool and Phenolic.

External finishes available include scratch render, acrylic and silicone textures and pebble dashing. These options are all available in a wide variety of colours. More information can be found under services.

See all our recently finished work and reviews from our customers on our Facebook…..

What are the benefits of EWI?

Installing external wall insulation can offer a wide variety of benefits ranging from substantial savings on energy bills to improving the visual appearance of your property by renewing the aesthetics of the outside walls potentially adding to its resale value To the right is a table showing how much you could save on your energy bill per year by installing solid wall insulation to your property.

This data is based on fuel prices as of October 2022. With household bills set to skyrocket, the cost of future utilities is unpredictable. You can be sure, however, that having external wall insulation will keep bills lower than leaving your walls uninsulated.

Better insulation will also improve your homes Energy Performance Certificate (EPC) rating which is an influencing factor when selling a property. Furthermore, due to new government regulations as of 2025 all new tenancies must have an EPC rating of Band C or above. Currently the regulations state rental properties require and EPC rating of Band E and above. Therefore, external wall insulation could be a fundamental resource to landlords looking to improve their EPC rating prior to the new regulations taking place.

Is your property suitable for external wall insulation?

To determine if your property is suitable for external wall insulation a full and detailed survey needs to be carried out by an experienced member of our team in order to establish the existing wall type, required insulation thickness and render finish; detailing to windows doors and facias is also a consideration, as is the removal and refitting of rainwater and other external pipes and fittings.

The suitability of external wall insulation on your property can also depend on factors such as planning permission, listed buildings or conservation area restrictions as they may prevent insulation from being installed externally so before any decisions are made, these agencies should be contacted.

Is money your only motivator?

Upgrading your home’s efficiency will drastically improve its carbon footprint. To the right is a table showing how many kilograms of CO2 emissions you could save each year with solid wall insulation.

If sustainability is at the heart of your renovation then you might see external wall insulation as good value for money. You’ll get the best result in terms of energy savings if upgrading the efficiency of your walls is part of a wider plan to improve your home’s the thermal performance.

On top of the financial and environmental benefit already stated EWI also offers many other benefits such as:

Reduces condensation on internal walls and can help prevent damp (but will not solve rising or penetration damp).

Fills cracks and gaps in brickwork, which will reduce draughts and increasing the sense of comfort

Increases the lifespan of your walls by protecting the brickwork and reducing moisture content

It improves weatherproofing and sound resistance

It does not reduce internal floor area of your home

Causes no disruption to the household while being installed

The solid wall insulation provides a new protective barrier to the elements, helping reduce maintenance costs over time.

It allows walls to contribute to thermal mass (the ‘tea cosy’ effect)

Can reduce solar heat gains in summer

Allows you the choice of colour and texture of the final finish

The system we use offers our clients a long-term guarantee

Why us?

10 YEAR GUARANTEE

All our systems come with a 10 year guarantee. As we are approved contractors for Wetherby Building System’s we are also able to offer a 10 year manufacturer’s guarantee when using their materials to complete jobs.

FAST & EFFICIENT

Due to our highly efficient office staff, we usually can schedule a survey and provide you with a quote within 3-5 days from the initial enquiry.

VERSATILE TO ALL SURFACES

Whether hacking off existing render, or going onto bare brick/breeze block, our team know all the relative preparation to ensure the render is installed properly.

AFTERCARE SERVICE

Once we have completed the work, we will contact you to advise when the scaffolding will be taken down and to ensure you were happy with our service.