Eddington Lot S2

Case Study

NORTH WEST OF CAMBRIDGE

Lot S2 is a 373-home, 4-block, 4-5 storey apartment complex. Part of Eddington community, northwest of Cambridge, it is becoming home to 8,500 people, see more.

Eddington was developed with Cambridge University to provide affordable, modern homes for staff and key workers, with 1,500 homes for sale on the open market.

The facade contract covered 4 Blocks with multiple systems and complex geometries. Block A is clad in Mechslip bays; GRC columns and fascias in Portland Shade and ‘Elements’ ppc aluminium overlapping cassette panels and spandrel panels, with flashings and copings in a Khaki Grey (bronze). The scope for Blocks B, C & D comprised ppc aluminium only, with brickwork by others.

The 4-5 storey buildings were designed and built to BREEAM Excellent, the Code for Sustainable Homes Level 5 and the new Part L Building Regulations, reducing carbon emissions by at least 31%. By using a recycle-grade aluminium subgrid, our team saved an extra 13.5 tonnes of carbon, compared with standard European aluminium.

The £55m Eddington development, serving the city of Cambridge, is the largest single capital project the University of Cambridge has undertaken in its 800-year history.

BENNETT CONSTRUCTION (LONDON)

"The best thing at Eddington Lot S2 was the collaboration between all teams on site ... all working towards the same goal and utility, delivering the project on time and to client satisfaction.

Quality throughout the job was very high, from substructure through to the finished cladding panels. Fire barrier installation and compliance was very good throughout the project. Independent inspections always scored near perfect, with very few snags raised throughout the job by our own management and inspection process.

Design coordination was excellent too, as there were a lot of bespoke roof details and terrace zone with large areas of cladding. The GRC and mech slip interface was well set out."

Ciaran O'Dwyer

Senior Site Manager

Challenges

The greatest challenge of this project were the complex geometries. Each material had a special design, calling for extra skill, care and high levels of coordination with manufacturers and site teams.

Variations and tolerances in the backing structure required site surveys and design adjustments.

The facades had a variety of textured brickwork patterns, with diamond patterns in the mechslip bays on the GRC framed elevations.

The curved GRC elements required bespoke design. Pre-fabrication required a long lead-in. Tolerances of only 5-10mm maximum left no room for error.

This design has some of the most complex coping geometry A²O has worked on. The design of the copings vary in two directions: rising and falling while projecting and receding.

A fire-stopping solution was needed to protect the fire barrier where balconies connect to the facade, for continuity of fire integrity & thermal insulation.

The install had to meet the Code for Sustainable Homes Level 5 and updated Building Regs Part L.

Delivery of the 4 blocks, each with distinct features and scope, was on a fast-paced programme.

The biggest challenge was managing quality on the architecturally demanding geometries across multiple systems while maintaining programme.

Solutions

With early engagement and a Revit model, the A²O design team developed bespoke details using Revit families. The Revit model improved visualisation, coordination and clash detection at interfaces.

Tolerance management required early manufacturer engagement and fully coordinated setting out.

The diamond patterns were achieved with careful setting-out, bespoke detailing and quality control on installation.

The GRC columns and fascias were designed by specialist facade engineering consultants. A²O then reflected the mould design in the detailing.

A²O rationalized the copings into buildable sections without compromising architectural intent. 3D modelling and close coordination with backing structures accommodated rises, falls and offsets.

Attention was given to balcony stub fireproofing, slab edge fire barriers, and interface detailing to ensure full compliance

High-performance insulation was specified and installed. Demanding U-values were achieved.

The programmes for all four blocks were designed and ran simultaneously to meet time constraints.

A²O achieved high quality standards, precision setting out and fire compliance, while meeting programme milestones and project budget.