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Super suburbia: How building on small sites can help to relieve the housing shortage

Enfield small sites

In the first of a series of articles looking at the future of housing in the UK, Riëtte Oosthuizen considers how suburbia can contribute to supplying the housing the nation needs

When it comes to tackling the housing crisis, small could very well prove to be beautiful. Specifically, we’re talking about small infill sites in and around town centres, additional layers on top of existing buildings and other such easily overlooked locations where a new dwelling could fit snugly but comfortably.

Such locations are now in the spotlight. Both the newly revised National Planning Policy Framework (NPPF) and the draft London Plan require local authorities to actively promote building on small sites – particularly the latter, in policy H2. It is creating enthusiasm and controversy in equal measure.

Concerns about lack of resources, unfair pressures on planning officers, and perceptions that residents simply would not support this type of development are paramount. Simultaneously, however, exciting new design and growth challenges are posed.

At HTA, we’ve been on the side of these overlooked sites for some time. Small sites offer the opportunity for more homes to be built in sustainable, accessible locations. At the same time, they can stimulate revival of suburban areas or neighbourhoods that have become run-down.

"Many small sites require truly innovative design approaches to delivering homes of high quality; at the same time they offer the opportunity to build the homes people aspire to live in"

But they ought not to be developed in isolation. Decision-making on smaller sites should form part of a wider concept of strategic growth. There should be a clear vision for how areas should change, set out in well-conceived design guidance. After all, many small sites require truly innovative design approaches to delivering homes of high quality; at the same time they offer the opportunity to build the homes people aspire to live in.

At present, there is a reluctance in the development industry to build any homes in the non-prime London market with a price tag more than £600,000. They simply don’t sell. This has led to over-delivery of flatted accommodation: 80 per cent of gross conventional housing supply in London in 2014/15 consisted of one and two-bedroom units. To be part of the solution, small sites need to address this problem.

Lessons from Fitzroof

What is small? Between draft and final versions, the NPPF backtracked its definition of a small site to one that can be as large as a hectare, having initially proposed a 0.5ha maximum. This is disappointing. Housing and economic land availability assessments require local authorities to consider broad locations for sites capable of delivering five or more dwellings on sites of 0.25ha and above. So sites between 0.25 and 0.5ha are already known; but the potential is in the sites up to 0.25ha. However, in research we have done for the CPRE on how councils tend to populate brownfield land registers, we found a reluctance to consider sites below 0.25ha. There is at present little incentive for them to do so.

The draft London Plan defines small sites as up to 0.25ha or delivering fewer than 25 homes. We have worked with many local authorities in London, delivering homes on sites smaller than 0.25ha. The outcome can be of magnificent quality, as our RTPI award for the Enfield Small Sites programme demonstrates. 

But these sites are notoriously difficult to get through the planning process unless there is specific policy support for the special circumstances that may be necessary for their successful delivery.

With the introduction of the Localism Act in 2011, our practice held enthusiastic seminars about the power of communities to change their neighbourhoods. This was partly fuelled by an original founding partner, Bernard Hunt, and a joint project he was undertaking in North London with 11 neighbours. Their proposal was to extend two groups of six terraced homes facing one another upwards with one storey, all designed by the same architect as a uniform proposal.

These 12 homes were recognised as a special group in the Conservation Area Statement prohibiting changes to the roof profile. Getting planning consent was an uphill battle, even though it was a sensitively designed scheme fully supported by 12 homeowners and adjoining neighbours, and evidently making a positive contribution to the character of the area and the homes themselves. Impact on ‘character’ is critical to the success of these schemes. Yet the essential components of ‘character’ are ill defined in most planning policy.

The ‘Fitzroof’ project (see image, above) sowed the seed for a bigger project, ‘Supurbia’, which considers how to deliver homes innovatively in new locations. With our immense housing need, it is essential to identify as many possible sources for new homes as possible. The potential of our suburban areas is immense. Beyond the typical suburban grain, there is also huge potential on rooftops and in land designated as commercial, such as retail parks and out-of-context employment land, which is surrounded by residential uses.

Case study: Enfield Small Sites

Award: Excellence in Planning to Deliver Homes – Small Schemes

Project: Enfield Small Sites

Key players: HTA Design LLP, Enfield Borough Council, Peter Barber Architects, Neilcott Construction

The Enfield Small Sites programme explored how small brownfield sites can deliver a significant number of homes through innovative design and collaborative planning in places that would otherwise have been overlooked.

Overall, the programme delivered 28 homes (5x1-bed, 9x2-bed, 14x3-bed) on six sites of 0.05-0.19 hectares in the London Borough of Enfield. Five of the sites had previously been used for garages, which were mostly unused and which tended to attract antisocial behaviour. One site had been a pub, which was demolished. Fifteen of the homes were built for affordable rent.

The constrained nature of the sites pushed planners and the architect into innovative approaches to addressing issues with light, overlooking and enhancement of the existing residential environment. The firm had to argue for a contemporary aesthetic, for example, and while attentive to policy, it had to put the case for at least one divergence from London-wide policy to deliver good quality, site-appropriate housing.

In that case, HTA asked for an exemption from providing wheelchair access on a sloping site that would have had a detrimental impact on the street scene. In its award submission, the firm drew attention to the overall enhancement of the environment, saying: “The redevelopment of these small brownfield sites introduces new street frontages and passive surveillance of the site and the local area, significantly improves the quality of the local environment.

“Each infill scheme has also been carefully designed to respect the height in relation to the surrounding dwellings and retain privacy for existing residents. The architectural composition of each small enhances the character of the area.”

The RTPI Awards judges picked up on the strong community consultation when praising the scheme: “We were impressed with the council’s proactive approach to delivering affordable housing on previously developed, difficult-to-develop land in their authority. The planners were central to this project, from using planning policy to identify the sites for development through to understanding the kind of housing the community wanted to resolving some of the design issues. As a result, the project has strong local support.”

Local initiative

With Supurbia, we have identified about 170 well-connected stations in outer London suburbs that are not located in opportunity areas or town centres, or are not covered by area action plans. These stations have Public Transport Accessiblity Level rating of 3 and above, meaning they are well connected.

Yet, at roughly 25 homes a hectare, they are surrounded by low-density housing. Analysing just three of the stations, we found that densities could increase to around 100 homes per hectare within a 5-10ha zone. This would produce on average 500 additional homes in each of these areas. Typologies could be introduced that still maintain a distinct suburban feel – mansion blocks, townhouses and mews houses with streets and squares.

"Within a radius of about 900 metres of the railway station, many London suburbs have housing typologies and garden sizes suited to such intensification"

What we find is that within a radius of about 900 metres of the station many London suburbs have housing typologies and garden sizes suited to such intensification – either as single or combined plots. Many suburban blocks dissected by disused lanes could be reinvigorated with mews homes, bringing them back into use.What’s more, there are good examples of residents who have come together and intensified plots with high-quality homes. But in the absence of readily available advice and funding, this usually requires an individual with unusual tenacity and some knowledge of construction. One example is that of the Hafer Road residents, led by Adam Street, and designed by Peter Barber Architects.

It’s a challenge to work with residents to support change on a very local and immediate scale. However, there are financial incentives. With Supurbia, we tested the viability of single homes intensifying their plots with an additional unit. Our examples delivered in the region of £140,000 to the owner-occupier.

In cases where existing homes are demolished, viability becomes more complicated, as typically the value that needs to be put in its place needs to be four times the original to be viable. But small sites offer opportunities to new types of enabling developers (which currently don’t exist widely) and in particular smaller and medium-sized builders/developers to deliver homes people need at a price they can afford.

What is small?

NPPF paragraph 68: Small and medium-sized sites can make an important contribution to meeting the housing requirement of an area, and are often built out relatively quickly. To promote the development of a good mix of sites local planning authorities should: Identify, through the development plan and brownfield registers, land to accommodate at least 10 per cent of their housing requirement on sites no larger than one hectare – unless it can be shown, through the preparation of relevant plan policies, that there are strong reasons why this 10 per cent target cannot be achieved.

Thinking ahead

The London Plan poses a challenge and opportunity to boroughs: the presumption in favour of small sites and its requirement to deliver 20 per cent of planned housing on them have had a mixed reception. Certain boroughs have already started exploring how suburban areas can deliver housing in innovative ways. Croydon, for example, is in the process of drafting a suburban intensification SPD.

Actively promoting small sites requires wider strategic thinking: cities are not stagnant, and there is no particular reason to think that post-war suburban infrastructure still suits today’s needs. As planning professionals, we need to think about how suburban areas are likely to change in future. Who will occupy them in 20 years’ time? What levels of car ownership will there be? What community infrastructure is necessary? What is the best way to provide green space? We currently seem to answer these critical questions by judging new development against what ‘is’ rather than what ‘should be’.

"Cities are not stagnant, and there is no particular reason to think that post-war suburban infrastructure still suits today’s needs"

The new policy emphasis on small sites challenges us to be forward-thinking. It is important as planning and design professionals to think collectively – and positively – about the challenge of subtle change in our suburban areas and neighbourhoods.

Though the local authority resourcing might currently be an issue, there is a groundswell of activity by local authorities that are building homes. This could, and should be better aligned with those who make policy. Design guidance to facilitate growth on small sites would be an essential component for successful intensification. There are good examples already – we need to start learning from one another.

Riëtte Oosthuizen is partner and head of planning with HTA Design LLP 

Photos | Picture-Plane