Developing Design and Buildability for Viable Residential Schemes
Blog | 16.09.20 | 0 comments
The UK needs more homes. Following the COVID-19 lockdown, the Government is keen to pair this urgent demand with measures to support the construction industry by relaxing planning requirements for residential developments.
After announcing revised planning rules for rooftop extensions, the Government has also brought forward proposals that will make new build residential developments easier too. The challenge for developers is to create schemes that are viable, appropriate for the location and attractive to potential residents.
At Edgeley Construction, we have worked on a huge variety of residential projects, from refurbishment and extensions of existing residential properties, to change of use schemes, heritage restoration projects and new build developments. Each has different challenges and characteristics, but our experience means that we are able to take an active role in design development. This means we can provide buildability and project management solutions that are essential to getting the job delivered, managing costs and, ultimately, enabling a good commercial return for the client.
Form and Footprint
A good example of these principles is the project we delivered at 374 Cold Harbour Lane to create a new build development of 10 apartments. The project was part of a wider scheme, utilising a confined vacant plot behind a disused Edwardian laundry, which was conserved, converted and refurbished as part of the same project.
The challenge with the vacant plot was that it had to be designed in a way that would comply with right to light planning requirements. The solution from the architect was to create a curved structure, which maximised the floor area while allowing sufficient natural light to reach neighbouring properties and reflecting the shape of the railway arches behind. This answered planning, unit size, commercial and aesthetic requirements, but threw up buildability challenges for both creating and cladding the structure.
The apartment building is a four-storey structure, including commercial accommodation at basement and ground level and apartments on levels one and two. It combines both a concrete and steel frame. The concrete frame provides the floorplate structure for each level, while the steel frame has been used from ground level to roof to create the structure for the curved elevations and the roof. Outset dormas and inset balconies allow maximum floorspace as the building rises, by providing headroom without blocking light to neighbouring properties. A basement, involving a dig out of around 3,360m3 of soil and management of a high water table via an Axter basement waterproofing and drainage solution, maximising the value of the building’s footprint by creating space below ground.
Thanks to the curved structure, the roof continues down to the side elevations of the building and a roofing system that could extend from the façade up to the flat roof was required.
This was where Edgeley’s design and build expertise was deployed. We developed the design to enable zinc cladding over the whole of the curved area, interfacing with an HPL cladding system for the vertical elevations. A double layer of thin ply was used to create the curve, followed by insulation and helping hand brackets. An additional two layers of ply were then installed, leaving a 50mm ventilation gap, followed by installation of the zinc, which is sufficiently malleable to mould to the contour of the structure.
To add to the installation challenges, the roof area also included AOVs, rooflights and solar PV panels, which required a significant amount of detailing. The interface between the zinc and HPL cladding materials, also required meticulous attention to detail and the roof areas of box-bay floor-to-ceiling windows at ground level have been waterproofed using a high performance Axter Reinforced Bituminous Membrane roofing system, for which we are an accredited Axtershield installer. This was colour-matched to the zinc cladding, requiring another smooth transition.
Design development was not the only requirement that drew on our experience of residential projects and confined London sites at 374 Cold Harbour Lane; our remit also involved ensuring the building could be delivered on a very confined site. This meant that the pre-construction phase also included negotiating party wall agreements and securing permission to use a 1.5 metre wide strip of land to the side of the new build’s footprint, which was our only access and storage area throughout the programme.
It’s added value skills and a problem-solving approach like this that makes all the difference between a construction contractor that can follow a brief and a construction partner that can resolve some of the inherent challenges in the design and location of the project.
The moves to relax planning laws are good news for both developers and communities where new homes are needed. In London, however, this will still mean delivering projects on confined and overlooked sites, so there will often be hurdles to overcome. Working with a construction company that can proactively offer solutions and leverage their in-house team to deliver them will be critical to progressing many proposed projects.