Do I own a small site?

What makes your land a viable plot to build on, and what features should you look out for?

Having a long garden or owning a dis-used garage is a good starting point. In this article we will look at some of the key opportunities and constraints that affect the number of homes that can be built on your land such as plot size, site access, overlooking and building line.

Small sites are defined as any property that is under 0.25 hectares or 2,500m² in size, or that would fit less than 25 homes. 2,500m² is an inconceivably large site for even the luckiest Landowner in any major city. Infact, 90% of the small sites we have seen over our years of site identification fall into the 1-9 home development capacity range; this is where we see the greatest opportunity for Landowners to build on their own land and the scale of site we will focus on in this article. This is not intended as an exhaustive list, more a rule of thumb to get you started on your journey into the world of small site property development.

The Whittering House by GPAD - Source: https://www.gpadlondonltd.com/projects/wittering-house/

Plot Size

It might seem obvious, but the first constraint to look out for is plot size. From a commercial perspective, if you ever want to sell the completed property, you will need enough space to fit a home on the plot that complies with dwelling space standards. Our friends at GPAD successfully made use of a 42m² (7m x 6m) garage plot in North London to create a family home spread over 3 levels. This is about as good as it gets in terms of use and quality of space. It’s worth noting that a generous amenity space and circa 500mm external wall thickness needs to be subtracted from the measured plot area to give you a more accurate estimation of the useable area for habitable rooms.

Site Access

Can the plot of land be accessed directly from a public highway? Is there enough continuous width to allow a person (1.2m) or a vehicle (3.7m) to pass through? Small backland sites, behind existing residential terraces for example, can often be accessed only by a narrow path. Consideration needs to be given in these circumstances for fire brigade access in case of an emergency. One should also think about how a space will be used in terms of walking in heavy shopping bags or the provision of nearby bin and bike storage.

Church Walk by Mikhail Riches Architects - Source: http://www.mikhailriches.com/project/church-walk-2/#slide-2

Overlooking, Outlook and Rights to Light

The reason you often see buildings cut at unusual angles is because of light and view, considered both from neighbouring properties and the proposed building itself. Take this commonly cited example from Mikhail Riches Architects, developed by the architects themselves, on Church Walk in Hackney. The building slopes sharply away from the neighbouring properties to not impact their light or outlook whilst at the same time creating outlook opportunities for the created homes. The rules for outlook and rights to light can vary depending on the Local Authority, but it's generally 25-45 degrees from the centre of a window to a habitable room within a distance of 18m. (See below diagram) It will be necessary to perform a daylight and shadow study to understand the impact on neighbouring properties in detail, which will be submitted with the planning application.

Diagram image from the Lewisham Small Sites SPD showing that new buildings should not obstruct a line drawn from the vertical centre of a habitable room window at a 25 degree angle, nor a 43 degree line struck from a point 1.6m above ground level at the boundary, where that boundary is within 10m of the rear of the existing property.

Building line

Considered sacrosanct, building line can rarely, if ever, not be adhered to when proposing new buildings that work within an existing context, particularly when it comes to the streetscape façade. The general rule of thumb is to look to the neighbouring structures to suggest the extents of the mass to be proposed for a new development. One not-too-uncommon exception is where the ground floor of a building can step out to the boundary to steal some more internal floor area. This is generally reserved for instances where there is an existing boundary wall, fence or hedge of significant height to effectively ‘hide’ the ground floor extension behind.

Diagram image from the Lewisham Small Sites SPD showing that the prevailing building line is defined by the principal face of an existing building or street facing the public highway. Minor projections, such as bay windows or porches, are excluded.

Other considerations

Some other considerations when trying to decide if you own a site include covenants, mature foliage and underground services. Does another property have the right to access theirs over yours? This would likely be annotated on the deed plan and can sometimes be resolved through negotiation with the other party. Are there any trees on the site that have a tree protection order (TPO) protecting them from removal? Are you aware of all of the underground services that pass below the site? None of these issues are definitely deal-breakers, but it does pay to be aware of them and to act accordingly before investing time and money into an unviable site.

Conclusion

Checking land for viability is the first step towards a self-build to sell project. Most of the considerations outlined above have solutions, but every case is different. The most valuable contribution when assessing the viability of a site will be from an experienced Architect who will be able to not only point out some of the common constraints, but also quickly work out possible solutions.

If you own land, have an appetite for development, and want to see how much you could earn by building on it, get in touch with the Urban R+D team for a free no-obligations viability assessment.