EWI Frequently Asked Questions



We’ve tried to answer as many questions as we can below but if you can’t find the answer you’re looking for please contact us.


What is external wall insulation (EWI), and what are its advantages?

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.

The advantages of installing EWI on a home are numerous and wide-ranging. EWI insulates the walls, which helps to reduce heat loss in cold weather and heat gain in warm weather. The result is a much more comfortable living environment within the home and a reduction in heating costs.

It is a bit like putting a tea cosy on a tea pot, with your house being the tea pot.

Government figures show savings can be up to 40%* if you keep to the same temperatures and settings you use at the moment. If you decide to make the house warmer or leave doors and windows open because the house is too hot you will obviously save less. There is also considerably less risk of condensation and damp walls.

The external appearance of the home will be dramatically improved. The finishes used are of the highest quality and are designed for minimal maintenance over a long period, saving you maintenance costs. Older homes are upgraded to equal or better the high insulation standard of new build properties.

*Information taken from Insulated Render & Cladding Association www.inca-ltd.org.uk

Why do I need EWI instead of cavity wall insulation?

Your home may be of either solid wall or non-traditional construction so there is no cavity to be filled. In order to prevent heat loss through these walls, EWI is a wall insulation system appropriate for these types of properties. EWI has a number of benefits over other more traditional means of insulating buildings such as cavity fill or insulated dry lining.

EWI is applied to the outside of the wall, so there is minimal disruption to the occupants of the building. The combination of the insulation and protective render finish ensures that the entire thickness of the supporting wall remains dry and warm, reducing the risk of structural damage and also minimises the risks of condensation or mould on the walls. The result is a warm environment for the winter months whilst the building is kept cool in the summer.

Do I need planning permission?

You will not need to seek planning permission unless the property is listed or in a conservation area. We will usually have discussed the scheme with your local authority to clarify before we approached you. The reason for this is that the works undertaken by Westdale Services are constructed of materials that provide a similar visual appearance – for example in terms of colour and style of brick used to the materials used in existing walls. The works will comply with the latest building regulations and we will sort out all of the documentation.

What is a U-value?

The U-value is a measure of heat loss through the walls, floor or roof of a building. The lower the U-value, the greater the resistance to heat loss and the less it will cost to heat the building.

A solid brick wall will typically have a U-value of 2.1W/m²K and installing EWI can reduce this to 0.28W/m²K or better which could cut heating costs by up to 40%*

*Information taken from Insulated Render & Cladding Association www.inca-ltd.org.uk

How much can I save on my heating bills by installing EWI?

In a poorly insulated property, Government figures estimate that up to one-third of the heat produced by a central heating system is lost through the walls.

The Energy Saving Trust estimates that heating costs can be reduced by up to 40% by installing EWI to solid walls, however your savings will depend on if you keep to the same temperatures and settings you use at the moment or if you decide to make your home warmer.

What type of finish can I have?

Westdale Services offer the widest range of finishes and colours to visually rejuvenate the appearance of your property and although the standard options may have already been suggested to you by our Resident Liaison Officer we understand that every property owner will have their own personal preference. We will accommodate this wherever possible.

Please be aware however that some options may require an additional contribution and may also cause a delay to the commencement of your works.

What if I change my mind?

You have every right to change your mind however if you have signed up to the scheme and we have already progressed works, you may be liable to a charge based on the works we have already completed.

Please also note that as of April 2015 the PAS:2030 standard has been amended to include a requirement that BT are informed wherever we carry out works near their lines. As a result of this Westdale are required to pay BT a fee. Should you cancel your order prior to works commencing Westdale reserve the right to pass on the BT fee.

What will the EWI work entail?

Once you have had your energy assessment and signed your contract you will be informed of an approximate date that your works will commence. The works will consist of preliminary surveys followed by enabling works to extend pipes, gas flues, external lights, alarms etc… Scaffold will then have to be erected so that the insulation boarding and render works can commence. Depending on the design, the scaffold may be taken down either before or on completion before pipes, external lights, aerial wires, sky dishes, etc. are re-instated before handover.

Will the insulation cover all of the external walls of my house?

Where possible, yes. However; if you have had any additional works already completed to your property over the years such as building extensions, conservatories, garages etc. it is unlikely they will require the system and under the funding guidelines these items will not be included in the offer. If you would like the property to be completely rendered for aesthetic reasons, we can advise and assist you with your request but there will be an additional charge for these works.

How long will the 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 could take anywhere between 4-6 weeks. This will include preparatory works such as extending flues and overflow pipes etc. and the re-instatement of the rain water pipes on completion.

Please note bad weather and freezing temperatures could extend this period.

Will I have to leave my home whilst the EWI work is carried out?

No. As EWI is applied to the outside walls, there is minimal disruption and it should not be necessary to vacate the property whilst works are carried out. It can however be a little noisy due to drilling of the walls, there should be little or no disturbance to the inside of the house and no need for re-decoration. However, we will require suitable access to the walls from the outside in order to put up scaffold and to carry out works.

Will you need to come into the property?

We will need access into your property to carry out our initial energy assessment and pre-works surveys and also a small element of enabling works, we should then only require further access when all of the insulation and render works are completed so as to finish off the plumbing and electrics.

What about my satellite dish/hanging baskets/rear gate?

We will remove fixtures and fittings (hanging baskets, house name plates etc…) as part of our initial enabling works and give them to you, the home owner, for safe keeping. However, if you have any valuable or cherished items, we would ask you to remove them before we get there. We can then re-install them for you once the works are complete.

If you have a satellite dish, an engineer will temporarily re-position it onto the scaffold so you do not lose signal whilst we are working on your property. He will require access to your property to do this. When works are complete it will be re-installed to the wall before the scaffold is removed.

Rear gates will be temporarily adapted or repositioned before we start the insulation works, however, please be aware that we will not be able to secure them fully until render works are completed and the scaffold is removed.

Do I need to inform my home insurance company?

The installation of the EWI system alone would leave you with no requirement to inform your home insurance, however, you may wish to let them know that scaffolding will be erected around your property for a period of time and that your house alarm may be required to be moved from your wall onto the scaffold whilst works are being undertaken.

Are you replacing the guttering?

No, not as standard. The EWI system finishes below your guttering line, therefore we do not need to alter this in any way. For an additional charge you may choose to have your guttering renewed and this should be discussed with your Resident Liaison Officer at sign up stage.

Will the weather affect you installing the EWI?

The weather can be a huge factor in the timescales involved in the installation of EWI, although this does depend on the severity of the weather. We can usually install the insulation in most weather conditions but ideally the render should only be put on in dryer climates. We also have to take into account health and safety issues for our employees, but any delays to works will be kept to a minimum.

What about my garden?

Whilst every effort will be made to protect your garden and plants within it, there may be slight disruption depending on the circumstances. We would recommend that you remove any cherished items/plants from a 2 metre area around your property before the scaffold is erected.

The operatives working at your property will make every effort to tidy up after themselves every day they work on your property. When works are completed and the scaffold is removed we will have a clean-up team who will tidy any remaining debris away. However, it must be pointed out that construction work can be messy at times and we would just ask you to bear with us for the duration of the works.

Will you be clearing up/making good afterwards?

See above (what about my garden?). In addition to this any render splashes will be wiped from your windows, doors, etc. but windows will not be fully cleaned.

My scaffold has been removed but my property is not 100% complete. Why?

We understand that occasionally in a homeowner’s eyes once the scaffold is dropped a property is complete, however, this is not the case in the majority of instances. We ask that you allow us approximately 2 weeks from your scaffold being dropped to fully complete any snagging works before officially handing over your property as complete.

Do you have a complaints procedure?

We strive to provide a first class service to all our customers, however, we understand there may be an occasion when you are not happy with the service you have received. If this is the case please contact our Customer Care Manager or your Resident Liaison Officer by writing, email or telephone. Your issue will be registered and you will be given a unique reference code that can be used to track its progress through to completion. See our complaints procedure here.

Where am I going to park my car?

If you usually park on your drive this may still be possible whilst the scaffold is up but will depend on the size of the access and parking area. On the days we are working on the house we would ask that all vehicles are moved a safe distance from the residence so that our operatives can work safely and without causing unnecessary damage to your car. If you do not then we would advise that the vehicle could become dusty or dirty while we are working and Westdale Services accept no responsibility for damage to vehicles.

What about my children, pets, etc.?

If you have children or pets we will obviously ask for you to keep them out of the way whilst we complete works. To enable you to do this we will strive to give you as much notice as possible before we start any elements of the work. We also need you to keep children well away from any materials, equipment and especially scaffolding needed during the works.

We would also ask that you try to keep gardens and working areas clean from any dog excrement, as Health and Safety prohibits us from asking men to work in areas where it is present.

Is there any type of security especially with scaffolding up?

There will be no security as such however at the end of every day all ladders will be removed from the scaffolds and the gates closed. If you do have any problems we would recommend you contact us and the police.

How do you fill the gaps around the windows/door/airbricks?

The EWI system is sealed to all openings using building trade sealants to provide a full weather tight finish.

How is the EWI system secured to the wall?

The system we are using is mechanically fixed to the walls using purpose-made fixing screws/dowels. It is therefore possible to insulate over existing render with a new system as the fixings go right through the render into the existing wall structure.

How long do I have to wait until you start?

Once you have signed up to the works we have to notify BT that we are going to start works on your property. We must give them approximately three weeks notice, in which time we are not allowed to touch your property. However, please be patient with us, we have a programme to follow and we will give you advance notice of a minimum one week prior to commencing works on your property. Contact our office to get an up to date idea of lead times.

I have a holiday booked/planned, is this going to create a problem?

We will need access to your property in some instances, e.g. for gas flues and plumbing extension works, so we would ask that as soon as we make contact with you regarding the works to your home you advise us of any planned holidays.  If you are absent when the works are planned as long as we have reasonable access to the full external walls of your property a lot of the works can be undertaken in your absence.  Please contact us to discuss further if this applies.

What guarantee do I get?

The external wall insulation works carry a 25 year insurance backed guarantee that you will receive through the post.  This could be received at any point following completion of your final render coat, if you have not received your documents with-in 3 months of the completion of your property please contact us and we will chase this up with the insurance company.

Why have I received a warranty document when my property is not complete?

This document is sent out to inform you that your works are being undertaken by a company who are registered as a member of the Certass or BBA Competent Person Scheme. Members of these schemes are able to certify that their installations adhere to current building regulations as an alternative to submitting a building notice to the local authority or using an approved inspector.

Will EWI add to the value of my property?

According to recent information the works could and should add value to your property. But for further details we would recommend you speak to an estate agent or their valuation surveyors.

Can I also have my loft insulated?

When your energy assessment was carried out your results may have suggested that a loft insulation top-up was required at your property and Westdale Services also have the capability to carry out these works. If you express an interest in this you will be contacted in due course by our specialist team who will visit you to arrange a pre-works inspection of your loft and book you in for a suitable time that the works can be completed.

We obviously require access to your property to be able to complete your loft works and would ideally ask that you make this possible at some point between us commencing your EWI works and the handover of your property.