Erneley Close EnerPHit

UK Passivhaus Awards 2015 Large Projects Finalist. A regeneration of two dilapidated blocks of flats in one of the poorest parts of Manchester, with EnerPHit as a mechanism for creating a sustainable low carbon community.

Architects Edelmann & Ebling and developer R-Gen Developments, together with Passivhaus Designer Eric Parks, have just completed an ambitious retrofit project to the EnerPHit standard at Erneley Close, Manchester, as part of Eastlands Homes’ £180 million decent homes programme. The project involved a major low energy refurbishment of 32 maisonettes (comprised of two blocks with 20 and 12 maisonettes, respectively), helping to massively improve energy performance, as well as being part of a ‘re-branding’ exercise for the area.

Structural issues and the numerous thermal bridges created by balconies and walkway meant that it turned out to be an immensely challenging project. Various structural issues emerged as the project was under way, requiring the project to be continually re-modelled and re-designed in PHPP (Passive House Planning Package) along the way. The project was undertaken by contractors The Casey Group who made a great collaborative contribution to problem-solving the many challenging practical, thermal bridging and airtightness issues on the project. This included the decision to use timber frame to replace the lately-discovered structurally un-sound brick/ block work internal skin. The project greatly benefited from having an airtightness champion on site and frequent air testing throughout the build helped focus the construction team’s mind.

21 Degrees designed, supplied and commissioned the MVHR systems for the project, as well as supplying GBS78 triple glazed timber windows and doors and a variety of Pro Clima airtightness products. 21° also provided extensive technical input and product support throughout the project. 21° Director Bill Butcher was also involved in giving some Passivhaus training to the building contractors before the project started on site.

MVHR systems & design

Designing the MVHR systems to fit into the maisonettes initially proved challenging for the team. 21° MVHR design service worked with Passivhaus mechanical & electrical expert Alan Clarke to design a system to fit the space available. The Zehnder ComfoAir 160 unit was chosen because of its compact form and performance characteristics, which enabled it to be located on the bathroom wall behind the bath. Space for the rigid steel ductwork was located by creating a ceiling void space over the bathroom and landing. 21° and Alan Clarke carefully designed and attenuated the system to ensure that the system operates quietly and with maximum efficiency. To ensure extra quality control, 21’s MVHR Technical Manager Andrew Farr gave a toolbox talk to ventilation installers on the project and he and our team commissioned the units after installation.

PERFORMANCE windows & doors

The project team specified GBS78 outward opening triple glazed timber windows (with a whole window Uw value of 0.9 W/m2K) for the project. 21° gave specialist design input into the window installation detailing. The combination of high thermal performance and good design detailing contributed to the project’s meeting strict EnerPHit requirements, during the Passive House Planning Package (PHPP) design process. To further help with installation detailing, 21° supplied its windows in pre-prepared insulated plywood boxes – as a complete installation module – to make installation easier and to help reduce thermal bridging around the window junctions.

Pro Clima airtightness products

Airtightness issues with the existing building fabric meant that the project had additional airtightness challenges. For example the volume of air travelling through the party walls was far in excess of original expectations. Pro Clima airtightness products including Solitex DA membrane, Tescon No 1 and Tescon Profil airtightness tapes and Orcon F adhesive were used extensively on the project, among other airtightness strategies. The products were supplied through Green Building Store, which also provided comprehensive technical product support , including organising Pro Clima toolbox talks. The completed project achieved 0.84 air changes @ 50Pa, successfully meeting EnerPHit criteria which requires 1.0 air changes @ 50 Pa or lower.