Rushmoor sets no fixed depth
Plenty of councils publish a maximum depth for a rear addition. Rushmoor doesn't. Its Home Improvements and Extensions SPD, adopted in February 2020, leans on a 45-degree test instead. Draw a line at 45 degrees from the middle of your neighbour's nearest habitable-room window. If your plans cross it, expect questions about lost light. The council calls it a rule of thumb, so passing isn't a promise and failing isn't an automatic no.
The rest of the guide is about proportion. A two-storey addition should keep its ridge below the main roof and match the pitch of the house, and the council would rather not see flat or false-pitch roofs at that height. Single storey may be flat.
Two less obvious tests catch people out. The garden you leave behind should be at least 30 square metres on a family house of two bedrooms or more (15 on a one or two person house), and drives and open front gardens don't count. Add a bedroom and the council may ask for another parking space too. Under the 2024 parking standards, a four-bedroom house outside the town centre zone is expected to have three spaces, where a three-bedroom one needs two. With no drive, raise this with the planners early.
What fits an Aldershot plot
Single-storey rear. Outside the conservation areas most houses can go 3 metres past the original back wall (4 on a detached) without an application, or up to 6 and 8 metres through Rushmoor's prior approval scheme, where neighbours get 21 days to comment. That bigger route is closed in a conservation area, and the council's own page names Wellesley as excluded.
Side return. Suits the Victorian terraces around Cargate Hill and Aldershot West, with a passage beside the back addition. Filling it counts as going beyond a side wall, so inside a conservation area it needs permission even at one storey.
Kitchen. Find the drains before you move the sink. Rushmoor's guide says building within 3 metres of a public sewer, or a metre of a public lateral drain, needs Thames Water's approval. Ask your designer to pull the sewer records early.
Open plan. Opening up the back of a red-brick terrace means steel, and Rushmoor's inspectors check beams as one of their structural stages and may want calculations. Have the engineer's drawings done before the builder prices it.
Wrap-around. Part side, part rear, so in Cargate or Manor Park it is a planning application from day one. On a corner plot the council wants the design to face both streets and avoid a long blank wall.
Two storey. Judged hard against the 45-degree line. Beside a semi, set the side addition back from the front and leave a gap to the boundary, because Rushmoor will resist anything that closes up the spaces between houses into a terrace.
Downstairs bedroom. A bedroom and shower room for an older relative sits within the normal rules. A fully self-contained annexe is another matter. The SPD says granny annexes generally need planning permission and shouldn't be fully self-contained.
Home office. Attached, it is just another room under the same limits. A cabin at the end of a small garden still eats into the outdoor space the council wants kept.
Planning. Three questions first. Is the house in a conservation area? Is it listed or locally listed? Is it on Wellesley? A yes to any of them means talking to Rushmoor's planning team before you pay for drawings.
Cost. No figures here. The local extras are what move an Aldershot price: a flood risk assessment in the south of town, a new parking space, a Thames Water agreement, steel. Compare three quotes against the same drawings.
Where the national limits stop
The government's technical guidance sets the permitted development limits for England. A side addition can be one storey, no taller than 4 metres and no wider than half the original house. A two-storey rear extension can go 3 metres deep and must stay 7 metres from the back boundary. Extensions and outbuildings together can't cover more than half the garden.
Conservation areas cover Cargate, Manor Park, the military town, Aldershot West and the canal corridor. Inside them, side extensions and two-storey rear extensions lose their permitted development status completely, and so does cladding. Rushmoor's prior approval page adds the Wellesley development to the excluded list, and the council says the controls on those homes reflect covenants on the properties. Read your deeds as well as the planning history.
Water in the south of town
The council's 2015 flood risk assessment placed sections of southern Aldershot near the Blackwater in Flood Zone 3, including housing around Stovold's Way, Boxall's Lane and Sandown Crescent. In February 1990 the river broke its banks and flooded that end of town. Zone 2 takes in an industrial strip by North Lane and Brookfield Road and a large area north of Aldershot Park. An extension application in either zone needs a flood risk assessment with it.
Surface water causes more of the trouble. The same study shows ponding along the A323 and North Lane, and the council's catchment study blames a surface water sewer network that can't cope when the Blackwater is high. A new roof sends more rain into those pipes, so ask how the drainage design deals with it. Underneath, most of the town sits on Bagshot sands with clay bands, and building control will want to see the foundations before they're filled.
Where these facts come from
- Rushmoor: Home Improvements and Extensions SPD (2020)
- Rushmoor: Car and Cycle Parking Standards SPD (2024)
- Rushmoor: larger home extensions
- Rushmoor: Wellesley Article 4 direction
- Rushmoor: conservation areas
- Rushmoor Level 1 Strategic Flood Risk Assessment (2015)
- Rushmoor: Aldershot Catchment Study briefing note
- Environment Agency: River Blackwater at Aldershot and Farnborough flood warning area
- British Geological Survey: Blackwater Valley (Aldershot) mineral assessment
- Rushmoor: building control site inspections
- GOV.UK: Permitted development rights for householders, technical guidance
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Questions people in Aldershot ask
We're off Boxall's Lane. Does flooding rule out an extension?
Not on its own, but it adds work. Check your address on the government's flood map. If you're in Zone 2 or 3, a flood risk assessment has to go in with any planning application.
Our Wellesley house is only a few years old. Can we use the 6 metre prior approval route?
Rushmoor's page says no. Wellesley is named among properties excluded from that scheme, so a deeper rear extension needs a full householder application.
If we add a fourth bedroom, do we need another parking space?
Possibly. Outside the town centre parking zone the standard rises from two spaces to three at four bedrooms. You only answer for the extra demand, not a shortfall that already exists.
We're on a corner plot. Is a side extension harder?
Usually, yes. Rushmoor's guide asks corner extensions to work with both street scenes, help the building turn the corner and avoid blank walls facing the road. Windows on the side elevation help.