External Wall Insulation

E Z External Wall Insulation is an specialist insulation contractor of Solid Wall Insulation (SWI) , External Wall Insulation (EWI).
External Wall Insulation (EWI) is a thermally insulated, protective, decorative exterior cladding procedure involving the use of expanded polystyrene, mineral wool, polyurethane foam or phenolic foam, covered with a reinforced high polymer modified render, finished with Acrylic or Silicone render.

✔ EWI can reduce your heating energy bill.

✔ Less energy your home use, less CO2 you will release.

✔ You can claim up to £5,000 off with the Green Homes Grant.

✔ Fibreglass reinforced, high polymer modified basecoat makes it a lot less likely to crack like the conventional cement render.

✔ External Wall Insulation has a water repellent finish therefore it will prevent penetrating damp.

✔ EWI creates thermally comfortable homes to in.

✔ Professionally installed External Wall Insulation will make your home look amazing.

✔ Silicone or Acrylic top coat doesn’t need painting, low maintenance ang long lasting.

✔ Walls will have much warmer surface temperature, therefore eliminates the risk of condensation and mould growth.

What is External Wall Insulation?


EWI is a method of upgrading the thermal performance and external appearance of existing properties.

EWI is a thermally insulated, protective, decorative exterior cladding procedure involving the use of expanded polystyrene, mineral wool, polyurethane foam or phenolic foam, covered with a reinforced high polymer modified render, finished with Acrylic or Silicone render.


The thickness of the insulation that will be fixed to wall dependents on the type of insulation. Different types of insulation material has different thermal values. When calculating the actual insulation requirements, consideration must be given to current Building Regulation standards. Consideration must also be given to exposure and durability, and whether the structure might be subjected to vandalism etc. In many older properties, special attention is required for concrete beams or lintels which act as thermal bridges providing poor insulation.

If your home was built before the 1920s, it’s likely the external walls are solid walls rather than cavity walls.

Solid walls have no gap, so they can’t be filled with cavity wall insulation.
Cavity walls are made of two layers with a gap or ‘cavity’ between them.
Solid walls can be insulated by adding an insulating layer, either on the inside or the outside, to prevent heat escaping through your walls while keeping the cold out.

If you insulate your solid wall from inside it is called internal wall insulation and you lose your very precious floor space and it incurs additional decorating costs, not to mention the inconvenience of having some insulation work done to all your walls at the same time while you are living in the house. If you insulate your solid wall from outside it is called External Wall Insulation.

External Wall Insulation insulation is usually more effective at cutting your energy bills than cavity wall insulation.

Why should I have EWI?

✔ Up to 35% of heat lost from poorly insulated buildings escapes through the walls.

✔ Insulated and rendered properties are transformed into warm, energy efficient and attractive homes/buildings.

✔ External Wall Insulation can reduce your heating energy bill by 25%.

✔ Less energy your home use, less CO2 you will release.

✔ You can claim up to £5,000 off with the Green Homes Grant.

✔ Fibreglass reinforced, high polymer modified basecoat makes it a lot less likely to crack like the conventional cement render.

✔ External Wall Insulation has a water repellent finish therefore it will prevent penetrating damp.

✔ External Wall Insulation creates thermally comfortable homes to in.

✔ Professionally installed External Wall Insulation will make your home look amazing.

✔ Silicone or Acrylic top coat doesn’t need painting, low maintenance ang long lasting.

✔ Walls will have much warmer surface temperature, therefore eliminates the risk of condensation and mould growth.

✔ External Wall Insulation systems also protect the building structure, prevent deterioration, and overcome thermal bridging and condensation problems.

✔ Lower your carbon footprint.

How much does EWI Cost?

There are two simple way to estimate the cost of installing External Wall Insulation to your house. One way is by property type and another way is by square meterage.

Property type:
Detached: £15K -20K
Semi Detached: £8K -14K
Terraced: £6K – 9K

Alternative way of estimating the cost of External Wall Insulation to your house, slightly more accurate by square meterage of the area to be insulated: It costs between £100 -£130 Per Square Meter. The variation in the per square meter rate will due to type of insulation required, thickness of insulation required, type of render finish required, whether or not existing render needs to be hacked backed to brick/blockwork, if scaffold required and the complexity of the scaffold etc.

You have to be very careful when estimating the cost using the square meter rate. Many customers / clients deduct the window and door openings. It is generally measured over the opening, instead of calculating the linear meter of the window and door revels.

How is EWI Installed?

Insulating panels are fixed to the wall using adhesive mortar.
Plastic capped fixings are driven through the insulating panels and around their perimeter into the wall to tie the panels securely to the wall.
Mortar is then applied over the insulating panels and the fixings.
An insulating mesh is then sunk into the mortar to hold the panels in position.
The mortar is sanded and painted with primer to prepare it for the render
The Coloured render finish is applied (available in any colour).

  1. First, Insulating panels are installed to the wall using adhesive.
  2. Secure the insulation panels by means of mechanical fixing to tie the panels securely to the wall.
  3. Base coat is then applied over the insulating panels and the fixings.
  4. Fibreglass reinforcement mesh is then embedded into the basecoat to hold the panels in position.
  5. Second coat of polymer modified basecoat applied over the reinforcement mesh and floated with sponge float.
  6. A coat of primer is painted to prepare it for the top coat.
  7. Silicone or Acrylic top coat render is applied (available in any colour).

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