General Questions

Will External Wall Insulation add value to my home?

Yes, it will renew and improve the appearance of your home, increasing its kerb appeal whilst weather proofing and increasing the life of your walls by protecting the brickwork. Also, External Wall Insulation will save you money by lowering your heating bills, reducing your noise level, improving your Energy Performance Certificate (EPC) rating and reducing your carbon footprint.

How much money can I save?

An average semi-detached home could typically save £450-500 per year on fuel costs (source: Energy Saving Trust) but this can be higher if your home is made more energy efficient through the use of thicker insulation as part of the external wall insulation. In a poorly insulated property, it is estimated that up to one-third of the heat produced by a central heating system is lost through the walls and the roof. The Energy Saving Trust estimates that heating costs can be reduced by up to 40% by installing External Wall Insulation to solid walls.

Is External Wall Insulation suitable for my home?

External Wall Insulation 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. Solid walls are found in most houses built before the 1920s so, if your property dates back to Edwardian, Victorian or Georgian times, its walls are likely to be solid. You can check the wall type by either consulting your deeds, or manually drilling a test hole in the wall. Another test would be to measure the wall thickness at an opening. Solid walls measure in the region of 225mm thick. The majority of terraced housing in the UK are of a solid wall construction. If you live in a mid-terraced property, it is possible to install EWI even if your neighbours on either side choose not to by providing a ‘stop end’ at the edge of your boundary.

Product System Questions

What is the best type of insulation for External Wall Insulation?

Your choice of insulation should be based upon your budget and any particular requirements. There are various insulation types to consider:

  • Expanded Polystyrene System (EPS)
    – One of the most cost effective solutions to give good insulation performance, combined with the benefit of being lightweight and easy to work with.
  • Mineral Fibre – This wool is fire retardant so in the event of a fire it will emit negligible amount of smoke and fumes. It also has the best acoustic insulating properties out of the three different materials used.
  • Phenolic
    – Normally comes at a higher cost than EPS or Mineral Fibre but gives a very high insulation performance, typically requiring in the region of 60% thickness of comparable insulations.

How do I choose between different types of finish?

The finish you choose is a personal choice taking into account your desired texture and colour. Consideration should be given to the durability and toughness of the surface needed and this will often be related to your type of home. Nesture will be able to advise you on the best choice of finish for your home since there is a wide choice of colours, textures, pebble dash and real and simulated brick effect finishes as well as rain cladding effects. Colour cards and samples are available by contacting Nesture on 0800 612 4494 or emailing us on

Is there a materials guarantee?

Nesture offers a standard guarantee certificate for its External Wall Insulation, guaranteeing the materials for a period of 25 years.

Installation Questions

Do I need planning permission for External Wall Insulation?

You should ask your local authority’s planning department whether planning permission is required to install External Wall Insulation as it is sometimes called. Planning permission is generally required if the property is within a conservation area or a designated area such as the green belt or countryside. In a local conservation area, the decision will depend upon the planning constraints of the particular conservation area. Your local authority’s planning department will be able to advise you on any special requirements, particularly relating to the necessary appearance of the finished work. There are a range of finishes which can be used to emulate your surrounding properties and samples can be provided to satisfy local authorities.

Will I have to leave my home whilst the External Wall Insulation work is carried out?

As External Wall Insulation is applied to the outside walls, there is minimal disruption and it is not necessary to leave your home whilst during the installation. Although it can be a little noisy due, for example, to some drilling of the walls, there should be little or no disturbance to the inside of your home and no need for redecoration.  Our Contractor Manager will require good access to the walls from the outside in order to carry out the work.

Will my garden be affected?

Our best care and attention will always be given to your home and garden during the work.

How long does External Wall Insulation work take? Do I need to be present?

The length of time taken to install External Wall Insulation will depend on the size of your home. As a guide, a typical 3-bedroom semi-detached house will take approximately 3-4 weeks from assembly to the dismantling of the scaffolding, but this is dependent on the weather.  This will include preparatory works such as extending flues and overflow pipes etc. and reinstatement of the rain water pipes. You will not need to be present during the application of the external wall insulation system, as all of the works will be carried out to the exterior of the building and access to the inside of your property is not generally required except at two stages when we need to enable the plumbing and electrics.

What is the best way of securing the external insulation system to the wall?

External Wall Insulation systems can be bonded or mechanically fixed, or a combination of both, to the walls using either special adhesives or purpose-made fixing screws/dowels. Generally, if the existing wall is painted or the surface is in a poor condition, the system will be mechanically fixed.  It is possible to insulate over existing render with a new system depending on the condition of the existing render and whether it is sound and well adhered to the wall. Most walls are suitable for External Wall Insulation and our Home Advice Consultant will be able to advise accordingly after doing a site survey.

What is the lifespan of the application?

All systems are tested by the BBA for life expectancy and will achieve a rating of a 25-year guarantee covering materials, workmanship and conditional damage to the building.

What happens when the work is finished?

When the work is completed, Nesture’s Site Manager will inspect the work to ensure that the application has been implemented to our high standards and your home and garden have been left in a clean and tidy state.

What do you do with window sills?

There are a number of options when it comes to window sills.

  • OverSills – We can fit an extended uPVC sill to best match the existing sill and extended pass the newly fitted insulation.
  • Recreated Sills – If your sills are of particular detail or age, we can re-create the sill using a number of methods to keep the appearance close to the original sills.
  • Under Sills – If there is a desire to keep the original sill intact we can fit an under sill which caps off the newly installed system under the original window sill.
    In all circumstances, please discuss your window sill option with your home advice consultant at the time of the survey.

What happens to my window reveals?

The way we approach window reveals will be determined by the width of the existing window frame along with your personal choice and should be discussed with your Home Advice Consultant at the time of your survey.

Does the system go below the Damp Proof Course (DPC)?

In most cases, we will fit our system to the level of the DPC. If requested we can paint this for you at a nominal fee. We can in some instances install a different system below the DPC but this should be discussed with your Home Advice Consultant should it be something you want more information on.

Do you fit new soffits, facias, and guttering?

Although not included as part of our solution we can offer new soffits, facias, and guttering. Please discuss with your Home Advice Consultant at the time of your survey.

If you have any more questions, please contact us on 0800 612 4494


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