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Frequently Asked Questions

What is External Wall Insulation?

External Wall Insulation is a form of insulation fixed to the exterior of an existing or new dwelling. This is then rendered to give a protective and decorative coating to the existing facade.

External Wall Insulation involves externally cladding a building with insulation boards, before applying a layer of basecoat render and then a final decorative finish. The overall result is not only a highly insulated, energy efficient home but one that is visually transformed on the outside. The finish can be smooth, textured, painted, tiled, panelled, pebble-dashed or finished with brick slips.

External Wall Insulation is an effective way to stop wasting energy and money at home. In winter, a well insulated house keeps warmth exactly where you need it‚ indoors.


Why should I consider external wall insulation?

Up to 35% of heat lost from poorly insulated buildings escapes through the walls. External wall insulation significantly reduces this heat loss, leading to a reduction in annual fuels bills by as much as 25%. External Wall Insulation systems also protect the building structure, prevent deterioration, and overcome thermal bridging and condensation problems. Newbuild In a newbuild instance EWI systems are the most cost effective way of achieving the current & future thermal performance requirements for the building regulations, achieving an internal environment with low temperature fluctuations and low heating requirements.


What are the key benefits to External Wall Insulation?

  • It makes your home warmer
  • It can save you on energy bills
  • It does not reduce the floor area of your home
  • It renews that appearance of outer walls
  • It improves weatherproofing and sound resistance
  • It increases the life of your walls by protecting the brickwork
  • Maintenance free
  • Extensive range of finishes and colours


How durable is External Wall Insulation?

External wall insulation is designed to have sufficient resistance to general wear and tear.  However, where damage is sustained, through accident or vandalism, replacement and repair is easily achieved.


What types of building are suitable for external wall insulation?

Virtually all common types of construction - new build (from steel frame to solid masonry) or refurbishment (traditional and non-traditional house types). 


Will I have to maintain and clean the system myself?

The insulation systems are generally maintenance free, although you may choose to wash down with soapy water as you would with any rendered wall. If you have chosen a brick finish, this would be treated as a normal brick wall with regards to cleaning requirements. The insulated walls should not be jet-washed or power-washed at any time.


Is Planning Permission required for External Wall Insulation?

It is always best to contact your local authority building control or planning department as you be required to have either Building Regulations approval or Planning approval depending on the circumstances of the project.


Do I need Building Regs Approval?

Under the Building Regs Part L1B 2010 you cannot replace or add a wall covering apart from paint to any solid wall without incorporating insulation to save energy and reduce heating costs . This applies to any internal wall renovation or external rendering of the wall and covers things like replacing or adding render,plaster or cladding and applies if you are working on at least 50% of an individual wall’s surface area. Mistakenly some people assume it has to be 50% of the whole house before you need to insulate but it is 50% of each individual wall.


What does U value mean?

U value is a measurement given to the thermal insulation qualities of a wall with the lower the figure the better . As a guide a new well insulated home will have a U value of around 0.25 and a solid wall home will generally be around 2.05 to 2.10 !!

The U value is therefore a measure of how quickly heat escapes through a structure to the outside and as a result also how much carbon is leaking through the walls as well. In todays hard pressed times with ever rising heating bills it is very important to have a home with a low U value if you wish to keep those winter bills down.


The Building Regs state that if the walls are worse than 0.7 in U value you have to fit insulation if adding or replacing a layer to an external wall . The target to try and hit is 0.3 but they will accept a higher figure if 0.3 is not achievable due to the property features etc. An average installation would be around 0.35 U value which still represents an improvement of over 80% in thermal efficiency of the wall.


How long will it take to install?

An average installation will take up to 2 weeks including erection and dismantling of scaffolding. The render and finishing processes are weather dependent, and may be delayed in very cold weather, rain or excessively hot weather.


Can I fix items to my walls after they are insulated?

Any satellite dishes, hanging baskets, gate posts etc which are identified at survey stage, will have timber pattresses fitted to support the fixings after the insulation is complete. Should you decide to fix other items at a later stage, where no timber pattress has been fixed, you should ensure that an appropriate fixing, long enough to pass through the insulation into the original wall, is used to avoid damaging the system.


What colours and finishes are available?

There is an extensive range of colours and finishes available





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