1-6 Copper Lane

The client-driven community housing development, 1-6 Copper Lane, is an innovative and highly collaborative solution to the problem of finding affordable housing in London. As with many innovative and inspirational projects JCT was the contract of choice, the Intermediate Building Contract provided the solution here.

1-6 Copper Lane is London’s first purpose-built co-housing scheme. Located in Stoke Newington, in the north of the city, the development consists of six homes that approach lifestyle choice and economics in such a way to make home ownership more affordable and to provide a more collaborative and communal neighbourhood.

The brief from the clients (a group of seven adults and six children, not all previously known to one another) was to have homes that reflected their desire to live in a low-impact environment, and for the buildings to allow them to carry out tasks together that they couldn’t as easily achieve individually. Activities such as gardening, childcare, and meals provide mutual support when shared, as well as companionship from the isolation of modern urban life.

The philosophy of the scheme’s architect and designer, Henley Halebrown Rorrison, was to reduce the households’ collective impact on the environment in the construction phase as well as in their daily lives. Building performance, including insulation, air-tightness, ‘whole-house’ ventilation and heat recovery, plays a vital role along with low-cost and proven technology. Renewable energy is provided by solar thermal panels. The embodied energy of the construction has also been carefully considered at each stage – recycling waste material from the demolition, a lightweight timber super-structure, timber cladding and fenestration, and partial green roofs.

The six homes range from 70m2 to 155m2 in size and the development includes a laundry, workshop, a 50m2 function room for parties and yoga, a workspace and communal gardens. The entire development space comes to some 795m2. In order to maximise internal light, the homes are anchored to three of the communal elements, the central upper courtyard, the shared activity and washroom on the ground floor and an area of open space around three sides of the development. This has the benefit of providing each home with two kinds of outlook.

Two pairs of three-level homes are situated at the north and south corners, with a pair of two-level homes east and west. This produces two raised corners with flat and pitched roofs facing each other across a brick paved courtyard deck. Both two-level homes have angled light canons at the outer corners of their roofs. The scheme is deliberately varied with angles segueing into straight lines and brick merging into timber without long external walls. The outward facing elevations are clad in heatcurved vertical timber boards which are intersected into three horizontal segments by two timber cornices. On the elevations facing the courtyard, the cladding is vertical timber boards with over-sized 44x44mm battens. This contrasts with the chalky Wieneberger brick elevations.

One of the significant challenges of the project was in the existing ground conditions and adopting the appropriate solution for the foundation works. The main problem was a layer of loose-made ground of around four metres in thickness in the foundations of the site. This, combined with the site’s previous industrial usage, meant there was a higher level of contamination. It was decided that excavation of the loose ground would prove to be far too costly and would also have a significant environmental impact in terms of the transport and equipment required, and the disposal of the waste material.

The project team devised a highly innovative solution to overcome the challenge: a cellular raft, which would add minimum weight to the base level, but would have maximum stiffness to allow for even distribution of the load. The raft itself was a 400mm-thick concrete reinforced structure with 270mm-diameter Cobiax void former spheres in between two layers of reinforcement. Despite being 400mm thick, the raft has the weight and material usage of only a 270mm raft. It also combines the functions of the lower ground floor slab and the foundation.

Despite the inventiveness of the raft solution, a settlement analysis and a dynamic probe test still needed to be carried out to determine that the average load increase was suitable, and that the variability of the ground (such as obstructions or buried historic foundations in the loosemade ground) would not result in too many hard spots. The settlement analysis predicted maximum values of 5mm and the probe testing revealed no hard spots and a generally low blow count across the site. This investigative work, combined with the light but strong raft and a partially buried ground floor, resulted in an economical solution for the foundations, with minimum embodied carbon.

1-6 Copper Lane is a thoughtful, original and daring scheme, which puts collaboration at the heart of the project, from conception through to the homes in use and the people that live there. For a so-called low-cost building solution, the quality and choice of materials, along with the design choices and layout, put many ‘luxury’ and supposedly architect-designed developments to shame.

The JCT Intermediate Building Contract is also an important part of the foundations on a project of this nature. Designed to be suitable for projects with a varying degree of complexity, such as 1-6 Copper Lane, its well-established provisions provide reassurance for both the clients and contractor. Being comprehensive, yet not as complex as forms used on larger projects, it provides an ideal framework for the type of collaboration that was required here, where the works and responsibilities of all parties would need to be clearly expressed.

1-6 Copper Lane could be the benchmark for intelligent, design led, efficient and economic housing in London, provided that the communal living philosophy became an attractive prospect to more people. It is an intriguing approach that turns the current mass-accepted method of providing urban housing on its head. Could 1-6 Copper Lane mark the start of a socio-architectural revolution? With the demand for affordable homes increasingly on the rise, we shouldn’t have to wait too long to find out.