Two angles drawn from next door's window
Tamworth sets no maximum depth for a back addition. It uses geometry. The borough's Design SPD, adopted in July 2019, says a single storey extension shouldn't cross a 45 degree line drawn from the middle of the nearest window or door of a habitable room next door. For two storeys the angle opens to 60 degrees, which means a lot less depth.
Clipping the corner off to dodge the line won't usually get you through. The guide says so outright.
Three more tests sit behind the angles. Nothing you add should push the house past 75% of its original footprint. No more than half the original back garden should be built on, counting sheds and outbuildings. And there should still be at least 10.5 metres of garden between the back wall of the new work and the rear fence. On a short plot that last figure can rule out a deep addition before the angles come into it.
None of this bites if the job is permitted development and no application is made. Planners still expect good design either way, and a builder who has read the SPD will draw something closer to approvable.
Building out to the side of a Tamworth semi
The town was planned around family houses after 1965, when it became an Expanding Town for Birmingham overspill, and a 2025 needs assessment shared with Lichfield finds a very high share of semis. Where a semi has a drive down one side, that strip is where people look first.
Planners here worry about what they call a terrace effect, where side additions fill every gap until a row of semis reads as one long block. So a two storey side extension here should normally step back 1 metre from the front at first floor, sit under the main ridge, and be no wider than half the original house. If a neighbour has a habitable room window facing the new side wall, the SPD wants 10.5 metres for a single storey and 12.5 for two.
Corner plots get extra scrutiny because everyone passing can see them.
The options, and how each suits a house here
Single storey rear. The job most Tamworth owners start with. On a semi outside a conservation area, 3 metres goes ahead as permitted development, and 6 metres is possible through the neighbour consultation route, which gives the council 42 days.
Side return. Belongs to the older red brick terraces, not the overspill estates. Many of those streets sit in conservation areas, where anything beyond a side wall needs an application.
Two storey. On a semi the 60 degree line from next door decides how deep you can go. The council also wants 21 metres between facing back windows, which some of the tighter estate layouts can't give.
Kitchen. With half the borough's homes at three bedrooms, a bigger kitchen often comes before a fourth bedroom. Flat roofs are discouraged, so a pitch that follows the house is the safer bet.
Wrap-around. Only an option where the side strip and the garden are both wide enough. The rear part should stay within the width of the back wall, so the L turns at the corner rather than spilling past it.
Open plan. Taking out the old back wall means a steel beam. Central Building Control, shared by six councils, will want the calculations.
Ground floor bedroom. A single storey side addition on a semi can take a bedroom and shower room for a parent who can't manage stairs. Keep it to half the width of the house.
Home office. A garden building counts towards the half of the garden you're allowed to cover, so on a smaller plot an office attached to the house leaves more lawn.
Planning. Away from the seven conservation areas, plenty of single storey work needs no application. Inside them, side extensions and two storey rear additions always do.
Cost. No Tamworth price from us. Foundations on river gravel near the Tame are a different job from foundations on mudstone up the hill.
River gravel, mudstone and old coal workings
Ground conditions change across a small borough. The historic town stands on Mercia Mudstone, with sand and gravel terraces over much of the centre and soft alluvium along the Tame and Anker valleys. To the east the rock is faulted Coal Measures, and Glascote, Wilnecote and Amington all grew on coal and clay pits.
If your house sits in a coal mining referral area, the council's validation checklist can ask for a Coal Mining Risk Assessment with any application, and a basic mining report won't count. Work that could disturb old seams or mine entries also needs a permit from the Mining Remediation Authority before you dig.
Flooding is the other check. The Local Plan describes extensive flood plain around the town centre and to the south, and the Environment Agency's River Tame strategy counted more than 3,000 properties at risk without the flood walls and embankments that now protect the Tamworth and Fazeley stretch. Inside Flood Zone 2 or 3, the council wants a flood risk assessment with any new build, extensions included. Check the Environment Agency's flood map before paying for drawings.
Where these facts come from
- Tamworth Design SPD (July 2019)
- Tamworth Borough Council: planning application validation checklist
- GOV.UK: permitted development rights for householders, technical guidance
- GOV.UK: home extensions and improvements in former coal mining areas
- Tamworth Local Plan 2006 to 2031
- Environment Agency: River Tame Flood Risk Management Strategy
- Staffordshire County Council: Tamworth Extensive Urban Survey
- Lichfield and Tamworth Housing and Economic Needs Assessment 2025
- Tamworth Borough Council: conservation areas and Article 4 directions
- Central Building Control partnership
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Questions people in Tamworth ask
How do I check the 45 degree line against my neighbour's kitchen window?
Take the middle of their nearest window or door to a habitable room, then draw a line at 45 degrees on plan towards your proposed extension. A single storey addition shouldn't cross it. For two storeys the council uses 60 degrees. Ask the planning team on 01827 709709 if you're unsure which rooms next door count.
We're a few streets from the Anker. Will a flood risk assessment be needed?
Only if the house is in Flood Zone 2 or 3, so check the Environment Agency's flood map for planning first. If it is, Tamworth's validation checklist asks for one with any new built development, and an application without it can be turned away as invalid.
Our side extension would stop three metres short of next door's side window. Is that a problem?
Very likely. Tamworth's design guide asks for 10.5 metres between a single storey side wall and a habitable room window on the next property, and 12.5 metres for two storeys. A blank side wall facing a landing or bathroom window is a different matter, so find out which room it serves.
Is east Tamworth affected by old mine workings?
Parts of it may be. Coal Measures run under the east of the borough. The Mining Remediation Authority's free online map shows whether a property is in a development high risk area. If yours is, allow time for a risk assessment.