Swisslab External Wall Insulation used in Cottage Renovation Project

The Old Cottages are two newly renovated period properties in Sarratt, near Rickmansworth. Originally six workers’ cottages, they have now been remodelled and renovated to form two semi-detached dwellings.


As part of the renovation, Alumasc’s Swisslab external wall insulation (EWI) system was specified as a result of owner Richard Haynes contacting energy saving specialists, the Mark Group. Advice was sought on how the thermal performance of the buildings could be improved, resulting in EWI being put forward.


The period solid brick construction meant that energy efficiency and aesthetics at The Old Cottages were both in need of improvement. As the Mark Group have an excellent, long-standing working relationship with Alumasc, they were confident that Swisslab External Wall Insulation would easily meet all the requirements of the scheme.

The Mark Group offer a dedicated EWI installation service for domestic properties, often helping homeowners and residents to take advantage of Government schemes and energy saving initiatives. This scheme was part-funded by the Energy Company Obligation (ECO).


The aim of the installation was to improve the thermal performance, thus lowering future energy bills at the two properties.

An additional goal was to improve the appearance of the The Old Cottages as owner, Richard Haynes, explains:

“The original properties looked awful. The exterior was painted brick and a number of doors and windows had been bricked up over the years.”

Alumasc’s Swisslab External Wall Insulation was the ideal choice for the project. This direct-fix insulated render system is commonly used for over-cladding existing properties and brings with it a number of benefits over and above the obvious improvements to thermal performance and upgrade of the building facade. These include, amongst others, weather protection and elimination of condensation and mould growth.


The Swisslab system used at The Old Cottages comprised 60mm phenolic insulation along with Alumasc’s high performance Silkolitt silicone render in standard white, the latter greatly improving the aesthetic appeal of the building.


As a result of the EWI installation, both properties at The Old Cottages have significantly improved thermal performance, with U-values now at 0.3W/(m2k) compared to the previous 2.10W/(m2k).

Speaking about the finished product, Richard Haynes, said:

“We’re really pleased with the results. Both houses look infinitely better and although this winter was kind to us in terms of the weather, I’m confident that the new insulation will benefit us even further in any future harsh winters. I’d definitely recommend EWI to other homeowners looking to increase energy efficiency in their properties.”

Sarah Shanahan, office manager at the Mark Group added:

“I’m personally really proud of The Old Cottages project. Not only do the properties look fantastic, but the improvement in energy efficiency is really impressive. At the Mark Group we’re always happy to install Swisslab – it’s a system we always refer back to.”

All Alumasc EWI systems are BBA approved, fully warranted and are available with a range of design and specification options, across many building types.

To find out more about Alumasc’s External Wall Insulation Systems click here or call +44 (0) 3335 771 700.