Issues arising from External Wall Insulation (EWI) Installations: guidance

A Consumer Guide to Issues Arising from External Wall Insulation (EWI) Installations in Welsh Properties

External Wall Insulation (EWI) can help make homes warmer, more comfortable and more energy efficient. When designed and installed correctly, it can also reduce energy bills and improve the appearance of a property.

However, in some cases problems can occur. These may be caused by poor installation, an unsuitable design, defects in materials, or a lack of ongoing maintenance. Problems can lead to water entering the building, damage to the external finish, damp and mould, and other issues that may affect the condition of the property.

Like other parts of a building, EWI systems should be inspected and maintained regularly. If your installation took place under the Nest scheme you will have been supplied with information on how to maintain your EWI.

Regular maintenance helps to ensure that the system remains:

• energy efficient
• weatherproof
• safe and secure
• visually attractive

Homeowners should periodically check for:

• cracks in the render or finish
• damaged sealants around windows and doors
• damage caused by impact
• staining or discolouration
• signs of water penetration

If damage is not repaired promptly, water may enter the system and cause dampness or mould inside the property. A lack of maintenance may affect any warranty or guarantee associated with the installation.

It is important to remember that not all problems are caused by faulty installation. Some issues can develop over time if maintenance is not carried out.

Step 1: Identify the problem

If you notice the following signs, there may be a problem with your external wall insulation (EWI):

• cracks in the render
• bulging or uneven wall surfaces
• staining or discolouration
• water entering the property
• damp patches on internal walls
• mould growth inside the home
• loose or damaged panels and fittings

If you notice any of these issues, it is a good idea to investigate further.

Step 2: Gather evidence

Keep a record of any problems you have identified.

You should:

• take photographs of the affected areas
• record when the problem first appeared
• keep copies of any correspondence about the issue
• note whether problems become worse during periods of heavy rain

Providing clear evidence can help when reporting the issue or making a claim under a guarantee.

Step 3: Check your paperwork

If possible, locate any documents relating to the installation.

These might include:

• a Homeowner Agreement
• installation certificates
• guarantee or warranty documents
• correspondence from the installer or scheme provider

These documents may help identify:

• the contractor who installed the insulation
• the insulation system used
• any warranty or guarantee that applies
• the organisation responsible for administering the guarantee

Some installations may be covered by an insurance-backed guarantee provided through organisations such as the Solid Wall Insulation Guarantee Agency (SWIGA) or the Insulation Assurance Authority (IAA).

Step 4: Contact the original installer

If you believe there may be a problem with the installation, contact the contractor who carried out the work.

The contractor should be given the opportunity to inspect the property and assess whether remedial work is required.

Their contact details may be included within your installation paperwork or guarantee documentation.

Step 5: Contact the guarantee provider

If the contractor cannot resolve the issue, or if you believe the work may be covered under a warranty or guarantee, contact the organisation that issued the guarantee.

They may be able to:

• confirm whether cover is in place
• explain what is covered
• arrange an inspection
• advise on the claims process

Step 6: If the contractor is no longer trading

If the installer has ceased trading, contact the organisation responsible for your guarantee or warranty.

If you are unsure who this is, gather any documents relating to the installation and contact the organisation named on your certificates or guarantee paperwork.

They may be able to:

• confirm whether cover remains in place
• identify the insurer
• replace lost documentation
• explain how to make a claim

Step 7: If you need help identifying the installer or guarantee provider

If you are unable to identify the original installer or guarantee provider, your local authority may be able to help identify the organisations involved in delivering the scheme and direct you to the appropriate point of contact.

Step 8: If the insurer has ceased trading

In some cases, the insurer providing the guarantee may no longer be trading.

You may be able to seek compensation through the Financial Services Compensation Scheme (FSCS).

The FSCS protects consumers when authorised financial services firms have failed.

If your EWI was installed under the Nest scheme, there is guidance available on the customer service you can expect and how to make a complaint about the scheme. It also sets out how the Nest team will respond to complaints, including timescales for responses.

If your EWI was installed under the Energy Company Obligation (ECO4) or the Great British Insulation Scheme (GBIS), the UK Government has published guidance explaining what to do if you believe the installation may be of poor quality. The guidance includes information on inspections, repairs and the support available to affected householders. It also explains the steps available to householders where concerns have been identified with wall insulation installed through ECO4 or GBIS.

Solid Wall Insulation Guarantee Agency (SWIGA)

SWIGA may be able to:

• confirm whether a property is covered by a guarantee
• explain the extent of the cover provided
• provide information about making a claim

The Insulation Assurance Authority

The  AA is a technical authority and industry body covering insulation, heating and renewable technologies. Its website includes information about its complaints procedure to help members of the Public who have a complaint about the workmanship or service provided by the IAA or an IAA registered business. 

Citizens Advice Consumer Service

Citizens Advice provides free and impartial advice on consumer issues and disputes.

Financial Services Compensation Scheme 

If an insurer has ceased trading, you may be able to obtain compensation through the Financial Services Compensation Scheme.

Welsh Government Home Improvement Loans

The Welsh Government provides funding for loans to eligible homeowners who are unable to pay for essential repair and improvement works. The loans are managed by local authorities.