Twenty-one metres, and a garden left over
Lancaster City Council's Householder Design Guide of December 2014 isn't a supplementary planning document, but it puts numbers on things many councils leave vague. Main windows facing main windows need at least 21 metres between them. A main window facing a blank wall needs 12. Afterwards, the usable garden shouldn't drop below 50 square metres, and the drive doesn't count.
Plenty of byelaw terrace yards were never 50 square metres to begin with, and the guide accepts the figure can vary with the grain of the area.
Next door's windows get the 45 degree test, applied differently for a ground floor window than for a first floor one. Even a single storey addition can overbear a neighbour, it warns. Keep the extension smaller than the house in width, depth and height, and match the roof pitch, including the neighbours' on a terrace.
Much work never reaches a planning officer. Under permitted development, a terraced or semi-detached house can go out 3 metres at the back from the original rear wall, or 4 metres if detached. Through the neighbour consultation route that becomes 6 or 8 metres, but you can't start until the council clears it or 42 days pass without a decision. Single storey means 4 metres high at most, with eaves no higher than 3 metres within 2 metres of a boundary.
What suits a Lancaster house
Ordered for the housing here. Each links to a full guide.
Single storey rear. The obvious first move on a terrace or semi, and often permitted development outside a conservation area. Use natural slate on any pitched roof if the house has it, because Lancaster's guide rules out imitation slate there.
Kitchen. Victorian back kitchens here often face a yard wall. Roof glazing usually beats a bigger footprint.
Side return. Fits a terrace where the back outrigger leaves a strip of yard alongside it. Watch the 45 degree line from the neighbour's back window, which is often only a short way from the boundary.
Open plan. Taking out a rubble stone back wall needs a steel and proper padstones. Have it designed before you choose the kitchen.
Wrap-around. A semi or detached house with a side drive can take one. The side leg needs an application, and the planners will want the gap to the boundary kept.
Two storey. Always an application in a conservation area. Elsewhere the guide wants a side addition visibly set back from the front with a lower ridge, and a rear one with no first floor window looking straight into next door's garden.
Ground floor bedroom. Steep terrace stairs are hard work later in life. A bedroom and level-access shower room at the back can keep someone at home, if the door widths are fixed on the drawings.
Home office. With a small yard and a 50 square metre garden test to think about, a study added to the house usually beats a cabin at the end of the garden.
Planning. Check the conservation area and Article 4 maps before anything else. Those two answers decide which rules apply.
Cost. We don't give a Lancaster figure. Coursed sandstone to match and natural slate cost more than block and tile, so ask three builders to price the same drawings.
Stone, slate and the conservation map
Much of Lancaster's older housing sits inside a conservation area, from the eleven character areas of the main city area to smaller ones such as Greaves Road, Aldcliffe Road and Bath Mill. There, national rules drop side extensions, anything over one storey at the back, and cladding from permitted development. A modest single storey rear addition can usually still go ahead without an application.
Westfield War Memorial Village goes further. Most of it sits under an Article 4 direction on external alterations, and the council's 2016 design guidance says extensions and outbuildings will likely need planning permission. It asks for extensions to be kept to a minimum, built in the house's own materials, and never roofed in concrete tile.
Buff Lancaster sandstone is hard to match from new, so start looking for reclaimed stone early.
Trees catch people out. In a conservation area you must give the council six weeks' written notice before cutting or felling a tree with a trunk 75mm across, measured 1.5 metres up. If one has to go for the build, the guide asks for three new trees for every one lost.
Building near the Lune
Storm Desmond in December 2015 pushed the Lune over its defences and flooded large parts of the city. The Caton Road defences now protect the stretch between Halton Weir and Skerton Bridge, but the council's flood studies still put land beside the river, including tidal stretches, in Flood Zone 3.
If your home is in Flood Zone 2 or 3 and the extension needs planning permission, send a flood risk assessment with the application. The Environment Agency's standing advice covers householder extensions up to 250 square metres. It asks for the new floor at least 600mm above the estimated flood level, or 300mm where that level is known with high certainty. If that can't be done, use flood resistant construction to the same height.
Unsure how the planners will see it? The council's Engage pre-application advice covers house extensions, with a site meeting every time.
Where these facts come from
- Lancaster City Council: Householder Design Guide (2014)
- Lancaster City Council: Conservation Advice Note 2
- Westfield Memorial Village Design Guidance (2016)
- Lancaster City Council: pre-application advice
- GOV.UK: Permitted development rights for householders, technical guidance
- Environment Agency: flood risk assessment standing advice
- Lancaster City Council: Caton Road flood defence scheme
- GOV.UK: Caton Road flood defences opened
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Questions people in Lancaster ask
My terrace has a small back yard. Does the 50 square metre garden rule stop me extending?
Not by itself. Usable garden shouldn't fall below 50 square metres, but that figure can vary with the grain of the area. On a tight terrace, the 45 degree line from next door's window is more likely to be the limit.
We live in Westfield War Memorial Village. Can we add a kitchen at the back?
Possibly, but plan on applying. An Article 4 direction covers most of the village, and the council's design guidance says extensions and outbuildings will likely need planning permission. Use the same stone and roofing as the cottage.
The house is sandstone with a slate roof. Can the extension be rendered block with a tiled roof?
Unlikely to be welcomed. Lancaster's guide wants stone matched in course height and block size, and says imitation slate isn't appropriate where the original roof is natural slate. In a conservation area, cladding with render or stone needs permission anyway.
There's a tree near where we'd build. We're in a conservation area. What do we do?
Give the council six weeks' written notice before any work to a tree with a trunk of 75mm or more, measured 1.5 metres above the ground. If your application affects trees, include an arboricultural implications assessment.