General FAQ’s


What Is External Wall Insulation (EWI)?

External Wall Insulation (EWI) is the application of an insulation layer to the outside wall of a building in order to improve the building’s energy efficiency. By minimising heat loss in cold weather and heat gain in warm weather, EWI creates a much more comfortable living environment and reduces heating costs.


Why Should I Choose EWI?

External wall insulation is one of the most effective ways of improving the energy efficiency of your property and has a number of benefits over other more traditional means of insulating buildings such as cavity fill or insulated dry lining.


How Much Will I Save On My Heating Bills By Installing EWI?

The Energy Savings Trust estimates that in a poorly insulated house, up to 1/3 of the heat generated internally can be lost through the walls and roof. Therefore, by insulating the loft and wrapping the walls externally with insulation heating costs can be reduced by around 40%.


Is EWI Suitable For My Property?

EWI is normally used to insulate solid wall properties, both brick and concrete, but it can also be used to further improve the performance of cavity walls, and non-traditional properties.


Pre Install FAQ’s


What should I do to prepare for the install?


Garden furniture/plants/ornaments/sheds that are next to or in contact with the walls of your property will have to be moved before the work can go ahead. If you are unable to move them, the contractor may be able to assist. You might also need to move any vehicle(s) including any caravans from your driveway and might be asked to cut back any bushes/trees. This will be discussed with you by the installer at the survey stage. When they carry out the survey, they will discuss any arrangements that need to be made, like removal of items on the outside of or vicinity of the house (e.g. hanging baskets or plants). As a rule, we would recommend that all items are moved at least 4 metres away from the property walls to avoid any damage. The installer is NOT liable for any damages to any items left out after request for removal is made. 

Will I Have To Leave My Home Whilst The EWI Work Is Carried Out?

The short answer is no – there’s no reason why you will need to leave you home when fitting external wall insulation.


What Are The Different Types Of EWI Finish?

EWI can transform the appearance of a property and there is an extensive range of different product, textured and coloured finishes to choose from.


Thin coat synthetic finishes come in silicone, acrylic or silicate plasters in a variety of colours and textures.

Thick coat mineral renders can be finished with dry dash aggregate or the final surface can be scraped back to leave a textured finish.

Brick slips or brick effect render offers a more natural finish.


Can EWI Be Used In New Build Or Just Refurbishment?

EWI can be, and frequently is incorporated into new builds as well as the refurbishment of existing properties. It’s widely incorporated into a new build specification in order to help achieve or surpass energy efficiency regulations and targets.


What about my satellite dish or tv aerial?

As you might expect, items fastened to the external wall surfaces of your home will need to be removed before the insulation is fitted and this includes satellite dishes and aerials. Satellite dishes will be removed during the works and temporarily attached to the scaffolding, where they will continue to work. There may be a short time when you won’t have access to your TV service in between the scaffolding work and the contractor will make the temporary adjustment. Other items that may need to be moved are alarm boxes and external lights.


What about my security alarm?

We recommend that your security alarm company attend to remove and reinstate. Please note that service connection may be lost for the duration of works


During install FAQ’s


How Long Does EWI Work Take?

The length of time taken to install EWI will depend on the size of the property but, as a guide, a typical 3-bedroom semi-detached house will take just a couple of weeks. This includes all preparatory works such as extending flues and overflow pipes etc


What Is A U-value?

A U-value is the measure of heat loss through the walls, floor or roof of a building. In the case of EWI and represented in watts per square metre, per degree Kelvin (W/m2K) it’s the sum of the thermal resistances of the layers that make up the walls after taking into account any gaps etc.


Is there much mess?

Fitting External Wall Insulation can produce some mess during installation but again, the installers will clear up afterwards.


Will there be scaffolding on my house?

Yes, scaffolding will be necessary to ensure the installers can safely access the whole surface of your external walls. The scaffolding will not prevent any access to the property and appropriate protection will be put up in accordance with health and safety legislation.


What will happen to pipes etc that are attached to my outside walls?

Essential items will be extended to accommodate your new insulation. This includes: • Rainwater and soil pipes • Flues • Window and door sills • Garden taps


If the standard extension option is unsuitable for any essential item attached to your home, then the surveyor will discuss alternative solutions with you and will ensure these meet safety requirements.


All air vents and gas combustion vents will be maintained for the duration of works. Decorative fixtures and fittings, such as hanging baskets or door canopies can be accommodated but this may involve a surcharge. To replace such items, fixings must be installed under the new wall covering before they can be reattached


Will there be any noise?

Installation involves drilling, attaching insulation boards and pebble-dashing, so unfortunately there will be a lot of noise at these times. The work will only take place during daylight hours. Pets may find the noise distressing, so please be aware, and always keep them supervised.


What If I have any questions while the works are underway?

During the work, the contractor will be your main point of contact. A resident liaison Officer will be appointed, and contact details given to you


Post Install FAQ’s


How many years of warranty do I get on my property?

The EWI work comes with a 25 year guarantee which covers any defects in materials and workmanship. Our warranty provider is SWIGA.


What documents do I receive at the end of the install?

After installation is complete, you, the customer, will receive a document pack from your installer. These documents detail the installation specifications and details of your warranty. It will also include


Will I need to carry out maintenance on the insulation?

The insulation itself will not require maintenance but the silicone seals e.g. around windows

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