Palmerston Court

MMC innovations & Passivhaus standards

Walsh were appointed by Urbanest pre-planning to work with AHMM on a proposal to replace four existing buildings on the site with an 850-bed student housing-led mixed-use development comprising office space, enterprise and community space and a new replacement pub.

The boundary site constraints were such that Walsh developed each of the fours blocks using 4-6m cantilevers over the lower four floors to maximise the development floor plates. This avoided costly and lengthy utility diversions and the cantilever structure became a significant feature of the development.

The development has been designed to meet the stringent specification of Passivhaus with consultants Henriksen Studios.

Passivhaus design had an impact on the structural design. Walsh designed the scheme with small floor spans to reduce the tolerance and deflections of the slabs. Masonry had to be designed without cavity ties and use of thermal breaks was avoided. Design of items such as door thresholds, window openings and all other penetrations required detailed interdisciplinary coordination to ensure airtightness. Similarly all shafts were constructed in concrete to aid air tightness.

Walsh undertook the embodied carbon assessments on the scheme and worked with the contractors to enable use of a 70% cement replacement mix within the substructure. A secondary benefit of the Passivhaus design using small spans resulted in a low embodied carbon floor design in the super structure frame.