Three metres on the boundary, and how to earn more
If your plans go to the council, the figure that matters most is three. Sunderland's Development Management guidance, adopted in 2021, says a single storey addition built on the shared boundary of a semi or terrace is normally held to 3 metres from the back wall. For a detached house it's 4 metres.
There's a way past that, and few other councils spell it out so plainly. For every 0.1 metre you set the wall in off the boundary, you can go 0.1 metre deeper, within reason. Or you can chamfer the corner away from the nearest boundary. Either way the guide also wants you clear of a 45 degree line drawn on plan from the middle of the neighbour's nearest ground floor window to a habitable room.
Two more limits catch people out. An addition mustn't severely erode the outdoor space, judged against the size of the house and the gardens nearby. And a two storey addition at the back is only approved where it does no unacceptable harm to the living conditions next door.
Stay within permitted development and none of this applies. The council's numbers only bite once you apply.
Cottage yards and semis with a drive
The Sunderland cottage already has an extension. Behind the single storey front block sits an offshoot that held the washhouse, and beyond that a yard which once had the coal shed and the toilet across it. Filling the gap beside the offshoot, or rebuilding the offshoot itself, is the usual project in Millfield, Pallion and Hendon. Keep a route through to the back lane for the bins.
Semis make up the largest group of homes in the city, about 38% in the council's 2017 housing survey. Many have a drive down the side. Build over it and the guide wants an off-road parking space kept.
Matching the project to the house
Yard infill. The natural move on a cottage or a Victorian terrace with an offshoot. Under national rules a side or infill addition must be single storey, no more than 4 metres high and no wider than half the original house.
Single storey at the back. On a semi outside a conservation area you can go 3 metres without applying, or up to 6 through prior approval, where neighbours get a say and you wait up to 42 days. If you need full permission instead, the council's 3 metre boundary rule takes over.
Kitchen. Most cottage infills become the kitchen, because that's where the old scullery was.
Open plan. Knocking the offshoot and the back wall into one room needs steel over a narrow span, and on a terrace the party wall is part of the job.
Two storey. Down the side of a semi, the guide asks for the first floor to step back at least 1 metre from the front, or a 1 metre gap to the boundary, so the pair doesn't merge into a terrace.
Wrap-around. Suits a semi or detached house with real width at the side. On a corner plot the side part should respect the building lines of the houses next to it.
Downstairs bedroom. Often easier on a bungalow, and Sunderland has a lot of them, roughly one home in ten. The council's guidance says main windows in the side wall of a side extension are unlikely to be acceptable, and bedrooms count, so face it to the garden.
Home office. A cottage yard rarely has room for a cabin and the bins. A study attached to the back of the house uses the space better.
Planning. In the 14 conservation areas, Ashbrooke and Roker Park among them, nothing can go at the side, nothing over one storey at the back and no cladding without permission. In the Green Belt the guide treats growth of more than 33% of the original house's volume or footprint as likely to be too much, and earlier extensions count.
Cost. There's no honest city-wide figure. A cottage infill against two party walls and a semi with a mining check are different jobs, so get three builders round.
Fatfield, the coast and the Coal Measures
The Environment Agency runs flood warning areas for streets by the Wear at Fatfield, including West and East Bridge Street, River View, Bonemill Lane and South View. If you live there and need an application, include a flood risk assessment. For a house extension that can be a short document you write yourself. The council's flood strategy says surface water is the wider problem, worst in the Coalfield and Washington, and the sea overtops at Roker's Marine Walk and Dykeland Road in Seaburn.
Below ground, the British Geological Survey records Coal Measures under the whole district and old workings beneath built-up streets. Check the government's coal mining map before the footings are designed. If the dig could reach a seam or an old shaft you need a permit from the Mining Remediation Authority. Report anything that opens up to the Authority's hazard line.
One last thing for building control. The council must be told when the work has legally begun, which for an extension means once the foundations and ground floor are in.
Where these facts come from
- Sunderland City Council: Development Management SPD (adopted June 2021)
- GOV.UK: permitted development rights for householders, technical guidance
- Tyne and Wear HER: Sunderland cottages
- Sunderland SHMA Update 2017 (dwelling types)
- Sunderland City Council: conservation areas
- Environment Agency: River Wear at Bonemill Lane and Riverview, Fatfield
- Environment Agency: River Wear at West and East Bridge Street, Fatfield
- GOV.UK: flood risk assessments for planning applications
- Sunderland City Council: local flood risk management strategy
- BGS: geology of the country around Sunderland
- GOV.UK: home extensions in former coal mining areas
- Sunderland City Council: commencement and completion notification
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Questions people in Sunderland ask
My neighbour has a 3 metre extension on the boundary. Can I build 4 metres next to it?
Under national permitted development, 4 metres on a semi means the prior approval route. If you need full permission, the council's guide asks you to set the wall 1 metre in off the boundary to earn the extra metre, or chamfer the corner away from the boundary.
Can I put a two storey side extension on my semi and line it up with the front?
The council's guidance prefers the first floor set back at least 1 metre, or a 1 metre gap kept to the boundary. Flush fronts that join two semis into a terrace are what it's trying to stop.
We live on Bonemill Lane in Fatfield. Can we still extend?
Yes, but if you need planning permission the application must include a flood risk assessment, because the street is in an Environment Agency flood warning area.
I want to build over my side drive. Will the council object?
It may if you lose all your parking. The guide asks for an off-road parking space to be kept.