The construction of two apartment buildings within the ground-breaking Climate Innovation District urban regeneration project in Leeds demonstrates how the EJOT CROSSFIX® substructure system can be used to incorporate rainscreen facades into highly sustainable buildings, without vastly increasing insulation depth.
Developed by Citu in partnership with leading Scandinavian architects White Arkitekter, the development is creating an entirely new sustainable neighbourhood with over 500 low energy homes with a PHPP (Passive House Planning Package) assessed design.
The development’s two apartment buildings, Aire Lofts and District Lofts, feature rear ventilated facades (RVFs) finished with two fibre cement panels externally. EJOT CROSSFIX® was chosen for the RVF substructure because it enabled the construction of a highly insulated envelope without compromising aesthetics, with the added benefit of streamlining installation.
Multiple performance goals
The façade of District Lofts was constructed by Hansen Facades using CROSSFIX, in conjunction with main contractor Artium Construction after the system’s successful deployment on Aire Lofts to attach secret-fix panels at ground and first floor levels.
The facade’s EWS1 fire safety rating had to be balanced with thermal and ventilation goals. Designed to a weighted U Value (based on a typical subframe arrangement) of 0.13 W/m²k, the RVF cavity had to accommodate insulation with a 250mm thickness and maintain the required ventilation for a system of this type.
A sustainable façade enabler
The CROSSFIX substructure consisted of a 220mm Konsole K1 in A2 stainless steel, complete with the Powerkey for enhanced structural stability in the same metal grade, supporting L, Z and T profiles. The EJOT package was completed with five types of stainless steel fasteners to provide secure assembly with consistent performance.
CROSSFIX’s stainless steel composition was important in achieving the façade’s thermal performance due to its very low thermal conductivity, minimising the potential for thermal bridging. Coupled with the CROSSFIX Konsole’s thermal stop, this ensured the facade’s U-value is lower than it would have been if other substructures had been used with the same insulation thickness.
Further whole life cycle advantages were provided due to CROSSFIX’s stainless steel composition, which is recyclable and requires relatively less energy to manufacture – confirmed by an Environmental Product Declaration (EPD).
A smart solution for modern construction methods
The multiple sustainability benefits provided by CROSSFIX, enhanced further through the system’s ‘non-flammable’ fire resistance rating and a unique design flexibility that enables use in both horizontal and vertical assembly, means it aligns well with the higher efficiency, safety and quality targets demanded in modern construction.
Find out more about EJOT CROSSFIX at https://www.ejot.co.uk/CROSSFIX_Citu_Case_Study.
