External Solid Wall Insulation, Tooting – South West London

This solid wall insulation job involved insulating a 1895 Victorian property with 100mm of insulation. We see 100’s of these properties every month and they all tend to be the same – cold and draughty!

The issue with these properties is that the solid wall construction does nothing to slow heat loss out of the property. By insulating some or all of the walls, you slow the movement of heat out of the house which means the heating system needs to work less hard to keep the house warm.

In this property in South West London, we wanted to insulate as much of it as possible without changing the appearance at the front of the house. It was for these reason that we decided to only insulate the back and sides of the house, leaving the front completely untouched to keep it in keeping with the rest of the street. Obviously in an ideal world from an energy saving point of view, we would insulate the whole of the property, however for this type of property we appreciate the aesthetic beauty of the brick itself and often it tends to be hard to get the relevant permissions from the local councils because  of the change in appearance. In this case it was deemed this was the best solution!

What Solid Wall Insulation system was used?

We opted to insulate the home with 100mm of EPS insulation with a mineral render and finished with a Silicon Silicate paint. This solid wall insulation system takes the u-value of the walls from 2.1W/m2k down to just 0.27W/m2k – now for most of us who don’t take in ‘u-value speak’ that is better than a brand new insulated cavity wall built today to conform with building regulations. The mineral render and Silicon Silicate paint provide a fantastic finish and have a raft of other advantages including the following:

The great thing about the solid wall insulation being applied to the outside of the brick is that this becomes a heat store, so will continue to release heat back into the room well after the heating has been turned off.

The job took just two weeks to carry out, with all the pipework extended to ensure a consistent thickness of insulation across all the walls. We ensured that waste pipes were only out of action for a 24 hour period to minimise the inconvenience on the household.


    External Solid Wall Insulation – Ealing, London

Ealing is a fairly central part of London and most of the houses there were built over 100 years ago, and most of these homes were constructed with solid 220mm brick walls. According to the Energy Saving Trust, uninsulated solid walls can account up to 35% of total heat loss, therefore addressing this area can make a big impact on the energy efficiency of the property.

The Elsley’s are benefiting from a much more insulated household, having installed external wall insulation to the back of their mid-terrace home. Most of you may think that mid-terrace properties are ok  in terms of keeping the heat as they only have two exposed walls  – while some of that is very true, as you can see the back of the house has in fact 3 exposed walls and if left uninsulated the heat just escapes and the property is not comfortable to live in.

Here, 100mm of Kreisel EPS solid wall insulation was used to insulate the external walls. The insulation boards stuck on with adhesive and are then mechanically fixed to the outside brick, held together by plastic caps. Once the boards are put in place they are then rendered over and finished with the waterproof top-coat.

The Elsley’s were pleased to have received some help from the Government grant, which was available to a limited number of applicants in 2014, with the rest of the project being self-funded.

According to the EPC report that was conducted before the installation date, the Elsley’s should save in the region of £200-£250 on their annual heating bills and as well as that should have a much cosier and warmer home.

    External Solid Wall Insulation- St Albans, Hertfordshire

St. Albans is a small a picturesque town on the edge of London, and if you have visited it yourself you would have noticed that the buildings are predominantly made out of solid brick walls.

This latest install happened right on the edge of town, which features many 1920s and 1930s solid brick properties. Mr Piper’s home is a 1920s detached property, and the reason he wanted to have solid wall insulation installed was not only to provide comfort and warmth but in addition to make his air source heat pump work more cost effectively.

100mm of the Kreisel EPS solution was installed to the main flank walls, one on the side and one on the back of the property. The Kreisel system is held together by mechanical fixings and reinforced but supplementary adhesive. The insulation is then prepared and finished over with a waterproof silicon silicut render.

The property had many openings for windows and doors and the key with external solid wall insulation is that as the walls are thickened with the boards, the window sills are extended and finished off so that no water penetrates the house. At the start of the insulating process the fixings like dishes, alarms and soil pipes are removed for the boards to be fixed in place. After this is done the fixings are put back into place and the top layers of adhesive, inner coat and outside render can be applied.

According to the energy reports carried out before and after the installation, the energy rating went up a whopping 15 points, going from a high E rating to a low C rating. Given that most solid brick properties have a poor energy score (less than than the average band D), having the solid wall insulation installed makes a big difference.

    External Solid Wall Insulation – Greenford, London

The external 100mm solid wall insulation solution has been installed on this semi-detached property in Greenford, Middlesex. In this case, Mr Smith has benefited a little bit from the Government grant with the rest of the project being self-financed.

Many properties in this part of Middlesex and Greater London were built either in the late 1800s or early 1900s with solid brick walls, which means cavity wall insulation is not possible to do. Solid wall insulation can either be installed on the inside or the outside of the property, and the customer chose external due to space considerations and to maximise the benefits of the externally applied render solution.

Having the 100mm EPS Kreisel system solution installed, has brought the property up to a band D rating on the EPC register. Not only has it improved the energy rating, the external wall solution will on average save Mr Smith’s family nearly £400 on heating bills. With the property being cosier and warmer it is also now protected from weathering, as the silicon silicut render goes on top of the insulation to provide all these additional benefits.

The photos below show some of the stages of the installation installation process:

Kreisel EPS external render system

Applying Kreisel EPS insulation boards.

external solid wall insulation

External solid wall insulation at the back of the property, Greenford London.

    External Wall Insulation – East London

Mr Mincher benefitted from the Government Green Deal Home Improvement Fund Grant, providing £6,000 towards the total cost of the works.

The house in Greenwich was insulated with 10cm thick EPS insulation boards and then rendered with a silicate render. The External Wall Insulation (EWI) system used was the Kreisel System, which is an approved Green Deal system.

Adding the 10cm of insulation to the walls resulted in a u-value of 0.27W/m2k, which is comparable with brand new cavity walls built today. 

It is estimated that this will save Mr Mincher over £180 a year (and it is worth noting that he is a low energy user) without taking into account any future energy price rises despite the fact in cash terms energy prices have doubled over the last 7 years.

In the following photos, you can see the transformation of the property over the course of the week.

Pre Install

Pre Install


Mayday Gardens during EWI installFinished house with coloured render finish.

    External Solid Wall Insulation – Brockley, London

Mr. Archer will now benefit from a near total external solid wall insulation of around 100mm, which has reduced the U-Value down to 0.3 W/m2K. This has increased his EPC rating from 57 to a remarkable 69 – nine above the UK average. His estimated savings will be just under £400 per year – not too shabby.

The External solid wall insulation installation includes the following:

What are some of the additional benefits of solid wall insulation

In the summer, a well insulated property is nice and cool. So, if there are many hot and sunny days, in July and August, the walls of the house will reduce the adverse effects of high solar radiance into the internal parts, ensuring you can put your feet up and stay comfortable.

The top coat render is self cleaning, which means the outside of your house will require little or no additional maintenance over the course of the lifetime of the system. However always check with the system designer for any specific maintenance requirements.

Finally a well insulated house opens up the possibilities to look at other efficient heating systems or renewable technologies. We would always recommend insulating the home first, before you install an air source heat pump or even putting up solar PV. Even though solar PV produces electricity and is not related to heat retention, money is actually better spent on improving the thermal efficiency of your home first.

If you would like to discuss solid wall insulation and would like more information about systems, installation processes or other areas, please give us a ring on 0208 144 0897 or send an email to enquiries@thegreenage.co.uk.

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