INCA Case Study: Dartford Refurbishment


Dartford Refurbishment

Project Type: Refurbishment

Building Type: Low Rise, Residential

Architect: N/A

System Designer: SPSEnvirowall

Installer: Low Carbon Exchange Ltd (LCX)

System & Finish: SPSEnvirowall System 1 + Silicone Render

U-value Achieved: 0.3 W/(m²K)

Low Carbon Exchange (LCX) is a contractor firmly focused on delivering tailored energy saving services to the social housing sector and homeowner market across the UK. Operating within this increasingly important sector, it is  involved in delivering a comprehensive range of renewable and energy saving initiatives from design stage through to repairs, maintenance and ongoing monitoring services. They also provide building fabric solutions including cavity wall insulation extraction and refill.

Its services are extended to over 35 social housing organisations, providing energy saving measures in the most cost effective manner. Its comprehensive portfolio includes; fabric and insulation solutions (including cavity wall insulation, loft insulation, external and internal solid wall insulation and draught proofing); renewable energy solutions (photovoltaics, air source heat pumps, ground source heat pumps and biomass boilers); services (‘Green Deal’ assessment, surveying, design, monitoring management, repairs and maintenance).

LCX is now into the 6th year of its External Wall Insulation (EWI) partnership with Dartford Borough Council. In total this programme covers around 300 mixed properties and during the study period they completed the recladding improvements for 77 local properties. 

An element of this partnership involved the design and retrofitting of an energy efficient external cladding and insulation system with the ambition of improving the measured U-Value of the solid wall properties from 2.0 to 0.3.

The programme is also noteworthy as the first application of an insulated (but ventilated) external gas box, which solves a perennial heat loss problem for most houses and, as part of attaining PAS 2035, insulation was extended below the damp proof course (see notes listed in the product key notes table, below).

These initiatives were achieved using Wall System 1 from SPSEnvirowall with a silicone finish (listed below) which together serve to improve the thermal efficiency of the properties. Attaining the desired U-Value. Furthermore, with the current rise in energy prices, the use of the EWI solution will continue significantly reduce the residents’ bills.

Product Key Notes Table



Fire Classification

Certification, Approvals, Testing

  Wall System 1

Wall System 1 fixed direct to a masonry substrate incorporating mineral wool insulation. It is a thin coat external wall insulation system that provides exceptional weathering and crack resistant properties combined with an inexhaustible range of colours ideally suited for this projects location and aesthetic finish.

A2 Non Combustible



  Silicone render

EnviroSil is a pre-mixed, highly water repellent silicone based through colour textured finish, allowing the façade to maintain its cleanliness via the natural cleaning process which occurs during rainfall.



  Thermally insulated gas cover box

Compatible, hinged gas cover box (external flange) for use with EWI Systems. Its is a fully insulated utility box enclosure that prevents Cold Bridging. Furthermore, it saves time to install with no disruption to the residents, avoiding lengthy delays with energy suppliers.



The design and retrofitting of an energy efficient EWI system resulted in the improvement of the measured U-Value from 2.0 to 0.3.


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