INCA: award-winning EWI

For almost forty years, External Wall Insulation (EWI) in the UK has been represented by INCA, the industry’s trade association, and INCA is now a flourishing organisation with its membership comprising the industry’s premier system designers, component suppliers and installers. Technical standards and excellent workmanship are the mantras of INCA and the highlight of INCA’s calendar is always the annual INCA awards, showcasing the best in External Wall Insulation. The 2020 awards were presented in an online ceremony to members and the winning projects demonstrate the tremendous variety of schemes carried out in both new build and refurbishment sectors and for residential, commercial and educational buildings.

External Wall Insulation is a technology employing insulation boards fixed to either masonry walls in a refurbishment setting, or to the sheathing layer of new build schemes built with steel framing or with a concrete frame with SFS infill. Beyond these common construction types, other less prominent building methods such as timber frame, ICF and offsite construction can also benefit from the use of EWI. System designers of EWI systems provide project-specific specifications outlining the adhesive and mechanical fixings of the insulation boards and the systems are finished with either high-grade decorative coatings or brick finishes.

Above:  Crosswall homes, Stoke-on-Trent: Winner of the 2020 Refurbishment Award

External Wall Insulation is an energy-saving, fabric-first measure targeted in various central and devolved Government schemes, the most recent being the Green Homes Grant Scheme, particularly the local authority delivery model for low income homes. With the existing UK housing stock requiring far more penetration of solid wall energy upgrades than has been achieved to date, the opportunity to find suitable communities to benefit is high for social landlords, and the positive outcomes extend well beyond purely energy efficiency for landlords, residents and the wider community.

The INCA Refurbishment Award recognises the use of EWI in the upgrading of existing buildings and throughout INCA’s history there have been tremendous examples of traditional masonry as well as the myriad of non-traditional properties being thermally improved and aesthetically transformed. The winner of the 2020 Award perfectly demonstrates this, the refurbishment of 7 ‘crosswall’ homes in Stoke on Trent by system designer Structherm and contractor Westdale Services.

A non-traditional construction type popular in the 1960s and ‘70s, Crosswall is unusual as the gable ends and separating party walls are block and brick construction with front and rear elevations formed from a timber frame covered with sheathing and exterior panelling. Structherm were able to specify their unique hybrid offer of structural EWI panels to strengthen and stiffen the front and rear elevations alongside their standard EWI system for the structurally sound masonry walls. Different insulation thicknesses for each system brought all elements of the completed properties to below 0.30 W/m2K u-value.

Above: The Cedars Development, Glasgow: Highly commended in the Architectural Merit category

In order to provide the most visually appealing finishes, Westdale replicated the original brick finishes with their Artbrick resin brick finish. This brought colour back to the brickwork and a cream render complemented the brick facades on the first floors. The client is delighted with the result as the properties are now warmer and more airtight and of course more energy efficient. The street housing the pilot properties has been rejuvenated, adding to their value and pleasing the residents of the area.

In the same Refurbishment category, Romorantin Place in Long Eaton was Highly Commended, a derelict, boarded-up residential block brought back to life by Westville Insulation using the EWI system provided by SPS Envirowall. Once the extensive refurbishment of the blocks began, Westville utilised SPS Envirowall’s Wall System 2 and included 130-180mm mineral wool insulation to achieve 0.3 u-values and the robust nature of the system was ideal for this type of refurbishment. It provided the client with a cost-effective solution that will protect the fabric of the building and extend its life way beyond the original design expectations.

Alongside the high quality products used on the scheme, Westville also actively became part of the joint management of the scheme to ensure that the programme ran to maximum efficiency. The programme was extremely complex due to the differences in wall build-ups and a lot of technical expertise was employed to overcome the detailing challenges, the shadow lines present and the attractive colour blending. The project was delivered on-time and on-budget and with significant resident satisfaction, ensuring more comfortable and attractive properties and lower fuel bills.

Above: Romorantin Place, Long Eaton: Highly commended in the Refurbishment category

In keeping with high-rise schemes that have featured in previous years of the awards, The Cedars Development in Glasgow are three significantly sized 1960s residential blocks refurbished to ultra low energy standards with the Sto StoTherm Mineral EWI system and awarded a Highly Commended in the Architectural Merit category. The aim of this complex project was to transform outdated properties into high quality, warm and comfortable city homes. Through seeking to improve the thermal performance of the buildings well beyond UK building standards, the design team were able to reduce space heating by as much as 80%. Designed for longevity, minimal cleaning and ensuring critical fire performance, the mineral wool insulation with render and the StoLotusan surface coating will provide excellent protection against algae growth and staining. These blocks are now a striking feature on the Glasgow skyline.

This year marks the 40th year of INCA and entries to the 2021 Awards promise to be just as varied, bold and innovative as the 2020 winners have proved to be.

For more information on these schemes and a full list of INCA members, visit the INCA website