Behind the garden wall: the secret of unlocking the backland site

As it becomes increasingly difficult to find land within dense city environments, opportunities lie in what cannot be seen – notably, the leftover land hidden behind the houses and garden walls of densely packed streetscapes.

These largely invisible areas can be used to deliver new homes, but developing them is not for the fainthearted. It requires a meticulous approach that can seem counterintuitive to many developers.

When vPPR set up back in 2009, only individuals and small developers had the appetite or stamina for this, but in recent years we have been increasingly approached by local councils and larger developers, which have realised the potential of the infill site to create multiple new homes. This includes vPPR’s recently completed Idlewild Mews for Croydon Council, an eight-unit affordable rent housing development (pictured).

The first hurdle comes in finding the site itself as it is rarely visible from the street. Most infill sites have very restricted access, never more than a car width and some have no legal access at all. This presents challenges both during the construction phase but also in relation to the future use of the site, with solutions to resident access, fire safety and refuse needing to be found.

There are always many neighbours and party wall agreements and planning are a big part of the process. Understandably, there is much concern over the proximity, overlooking, loss of daylight and general change.

Perhaps the greatest challenge of all is the bespoke nature of the infill site. It comes in all shapes and sizes with uneven edge conditions. It is restricted in terms of space and light. No two sites are the same and each will require its own bespoke solution. This however is also the joy of them – it’s an opportunity to create unique and highly desirable homes.

Our experience has shown that key considerations in transforming the infill site into new homes are as follows:

• A good relationship with the neighbours will both make the process smoother, but more importantly their cooperation is often needed in order to make the site viable. Buying a corner of a garden or a strip of land for access might make all the difference to whether the project is feasible or not.
• An inside-out, upside-down design approach will often maximise the project efficiency. Due to the proximity of neighbours, the proposal will need to be inward looking and feature courtyards or “outdoor” rooms to bring light and ventilation into a design.
• Being the most visible aspect to neighbours, we like to think of the roof as a third façade and design it with this in mind. On very restricted sites, the roof is vital to bring light into the house, and for this reason it is logical to position living spaces upstairs.
• The relationship to the building and the garden wall needs to be carefully considered from the start. There can be benefits in both offsetting from the walls (no party wall agreements) or building directly on the wall (maximising space), but this will depend on the location of the sites and associated costs.
• The access and geometry of a building demanded by the site present an opportunity to create a unique sense of community through shared outdoor space. While the outdoor space is often compressed, there is an intimacy to this that that is enhanced by the sense of space created by the gardens beyond.

Returning to Idlewild Mews, this is not your typical social housing project. The nature of the infill site provides opportunities for the building to have those intangible qualities that are so desirable but often lost in larger developments. The project is dense yet private, the form is dynamic but highly efficient and there is a sense of pride and appropriation by the residents that comes of living on such a unique site.

The lessons learned from these infill sites shouldn’t remain hidden behind the garden wall. They can be applied equally effectively to much larger, non-infill sites even if it means taking a more unconventional approach.