So a disclaimer here right off the bat, we’re a London centric practice, so as followers of the blog may have noticed, I frequently cover issues that relate to residential design specific to the London context. Of course this is probably no surprise as London is where we’re based. And being a small practice, a lot of our projects involve alterations and extensions to properties that are often within close proximity to other neighbouring buildings. So we’re adept at designing around issues that this brings up such as overlooking. So if you’re planning to build along a shared boundary for your single storey or double storey extension, here are the key things to bear in mind for your project.
Planning application process
From a planning perspective, building a single storey extension along a shared boundary should have no issues gaining planning approval providing it falls within Permitted Development Rights or the local authorities planning policy.
When looking to extend beyond three metres from the original rear wall for a terraced house under ‘Notification for Prior Approval for a Proposed Larger Home Extension’, then building along a shared boundary could be an issue. The process is subject to a ‘Neighbour Consultation Scheme’ where adjoining owners that share a boundary can object to the plans, therefore leading to a refusal of the application. You might find a previous post on this subject of interest.
Accessing very early on during the design stages how your proposal to build along a shared boundary will affect the daylight into adjoining owners and how their outlook will be affected as well working through any concerns raised could help with getting that larger single storey extension under Permitted Development.
It’s worth noting that the original house would be as it was first built or as it stood on 1 July 1948.
So that’s for single storey ground floor extension. What about first floor extensions?
Although double storey extensions can be constructed under Permitted Development, with terrace houses this is less likely. If an extension falls within two meters of an adjoining boundary, then the eaves height of the overall extension cannot go higher than three metres. So that rules out a double storey extension under Permitted Development if your property is part of a terrace and you’re planning to build along a shared boundary.
Of course, submitting under Householder Planning Application is possible and is subject to different planning policies to Permitted Development. But in order to be successful in gaining approval, requires a design proposal that does not take light away from or appear over bearing for neighbouring properties.
The room uses are important here also, so if your neighbour has a bedroom window that currently enjoys light and view out, then building along the boundary would adversely affect their amenity. But if it’s a window to a staircase or a bathroom, both considered non-habitable rooms, then the likelihood of getting planning approval is greater. Also how far you build out is key to making sure that your neighbour’s amenities are not negatively affected.
Party wall matters
Having succeeded in a gaining planning permission, the next thing to consider when planning to build along a shared boundary is the Party Wall Act. It can be a process that can run smoothly with an agreement reached between you and your neighbour with no surveyors appointed. Or can become a complicated process requiring the appointment of one or more surveyors.
I advise clients that early discussions with their neighbours and addressing any of their neighbours’ concerns can influence how the party wall process will go. Worth taking the time to hold those early discussions, as the appointment of surveyors will affect the project budget as you would be responsible for settling all professional fees in connection with your project.
Building along the boundary a shared boundary will require work that falls within the Party Wall Act, such as excavating close to your neighbour’s foundations, building a wall along the shared boundary, toothing new brickwork into the existing party wall structure.
A notice must be served to your neighbours before the proposed work can be carried out. The notice can be issued by anyone, including yourself. It’s worth mentioning that although your architect could issue the notice on your behalf, it’s best avoided as a conflict of interest could arise if your neighbours dissent and the process becomes more involved.
Further information can be found here about the Party Wall Act along with template examples of the various notices that may apply to your project. If your neighbours dissent your initial notice, then party wall surveyor/s must be appointed.
So when planning to build along a shared boundary…
thinking through during the early stages about how your plans will affect your neighbour’s property and amenity is important to understanding your chances of getting planning approval. Also as with any project that is likely to affect the adjoining property, having those early informal discussions and alleviating any concerns where possible is not only neighbourly, but will also contribute to making your project run smoothly.
And finally, when planning to build along a shared boundary, don’t forget the all important Party Wall Act and serving appropriate notices to your neighbours before any building work starts.
Although we don’t provide services in connection with party wall matters – we prefer designing and avoiding conflicts of interest – we can help with planning matters relating to your project. So feel free to leave us questions you may have in the comment box below or contact us for more specific project enquiries.