Basement
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in Camden Town, NW1
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Many Camden Town houses already have a lower floor, and Camden treats improving it very differently from digging a new one.
Camden's appraisal of the residential streets finds houses generally of three storeys raised on basements, and buildings set back from the pavement precisely to make room for basement areas or front gardens.
In NW1 we survey the lower floor you already have, its height, damp, light and drains, before anyone discusses going deeper.
Source: Camden: Camden Town Conservation Area Appraisal and Management Strategy (adopted 4 October 2007)
Lower floors that already exist
Jeffrey's Street's late Georgian houses mostly have three storeys over a basement, the narrow basement areas in front fenced with iron railings.
Ivor Street splits in two: on the south side the houses have basements, lightwells and raised ground floors, while the north side has narrow front gardens and no lightwells.
Rochester's villas and terraces of the 1840s include some with half basements and raised ground floors.
Where a lower floor exists, tanking, a modest floor lowering and better light from the rear are usually our first proposal.
Sources: Camden: Jeffrey's Street Conservation Area Statement (agreed 19 November 2002), Camden: Rochester Conservation Area Statement (agreed 12 December 2001)
Policy A5 and the 2017 Article 4 Direction
Policy A5 of the Camden Local Plan lets a basement go ahead only once the council is satisfied it will not harm neighbouring properties; the structure, the ground or the water conditions; the area's character and amenity; or the building's architecture and heritage assets.
In size, A5 allows one storey only, not below an existing basement, beneath no more than 50 per cent of each garden, with an area under one and a half times the footprint of the house.
Its Basement Impact Assessment has to show damage to neighbouring buildings held to Burland category 1, very slight.
Camden's Article 4 Direction of 1 June 2017 removed the permitted development right for basements, so in this borough any basement or lightwell excavation is a planning application.
Sources: Camden Local Plan 2017, Camden Planning Guidance: Basements (January 2021)
Basements in the Camden Square Conservation Area
Camden describes the area as houses in large gardens with many trees, and wants basement schemes not to harm the buildings, their garden settings or nearby trees.
It must be satisfied that demolition and construction will not damage the house or the buildings joined to it, and it normally resists basements that front the road.
The appraisal calls new basement areas dug where none existed out of character.
Source: Camden: Camden Square Conservation Area Appraisal and Management Strategy (adopted 11 March 2011)
Railway tunnels under Camden Square
The Midland Railway, the first line out of St Pancras, was built in 1864 to 1867 in two cut-and-fill tunnels that pass diagonally under Camden Road, Camden Square and the mews.
Before drawing any excavation near that line we obtain the records of the tunnels and cuttings and have the engineer set the excavation limits from them.
Source: Camden: Camden Square Conservation Area Appraisal and Management Strategy (adopted 11 March 2011)
Lightwells in front of former shops
Basement lightwells in front of Murray Street and York Way buildings first built as shops are likely to be resisted.
Where a shop becomes a home in the Camden Square area, Camden expects the shopfront kept and new lightwells in front of it generally refused.
Along Murray Street's parade, digging front lightwells was one of the changes the appraisal counted as harmful when shops became flats.
Source: Camden: Camden Square Conservation Area Appraisal and Management Strategy (adopted 11 March 2011)
Near the canal: archaeology and old industry
The canal's route descends through a series of locks into the valley of the River Fleet, bending to fit the street grid of early Camden Town.
Camden's canal strategy notes that new buildings or basement digs may disturb archaeological deposits, industrial remains included, and that it will want a site evaluation.
Our desk study for a canal-side address maps old wharves and water levels before any trial pit is dug.
Source: Camden: Regent's Canal Conservation Area Appraisal and Management Strategy (adopted 11 September 2008)
New flats below ground
Around Camden Square the council's strategy expects to refuse a new dwelling made by excavating a basement wherever harm to the conservation area is shown.
Lowering an existing garden flat is not the same as adding a new one, so our drawings state plainly which is proposed.
Source: Camden: Camden Square Conservation Area Appraisal and Management Strategy (adopted 11 March 2011)
Gardens, trees and soil cover
With trees on or next to a basement site, street trees included, an arboricultural report showing their protection goes with the application.
Where a basement runs beyond the footprint of the house, Camden looks for at least a metre of soil on top, for planting and so rain can soak in.
Sources: Camden: Camden Square Conservation Area Appraisal and Management Strategy (adopted 11 March 2011), Camden Planning Guidance: Basements (January 2021)
Neighbours and the terrace either side
Excavating below and close to the level of a neighbour's foundations is one of the triggers for a party wall notice.
A Construction Management Plan is something Camden will generally ask for on basement developments, its Local Plan says.
Readings from monitoring points on both party walls are shared with the surveyors at every stage of the dig.
Sources: GOV.UK: Party walls and building work, Camden Local Plan 2017
The Basement Impact Assessment
Camden's guidance divides the assessment into screening, scoping, site investigation and study, impact assessment, and finally review and decision making.
It must start with a non-technical summary a lay reader can understand, and describe subsidence risk on the Burland Scale, whose categories turn on how easily the damage could be repaired.
Camden asks for the technical reports to come from a chartered engineer or chartered geologist holding suitable qualifications.
Sources: Camden Planning Guidance: Basements (January 2021), Camden Council: Basement developments and planning applications
Listed houses
Camden's basement guidance requires listed building consent for a new basement, or for enlarging an existing one, in a listed building, alongside any planning permission the work needs.
On Crowndale Road, the listed 1840s terrace at Nos 31 to 53 has three floors raised on basements behind railed gardens.
Sources: Camden Planning Guidance: Basements (January 2021), Camden: Camden Town Conservation Area Appraisal and Management Strategy (adopted 4 October 2007)
Spoil, skips and the pavement
Every skip for the spoil runs on a Camden licence that the skip contractor itself must request, with five clear working days' notice.
Historic York paving stones and coal-hole covers still survive in the Camden Town Conservation Area's pavements.
Spoil leaves by conveyor through a protected route to a skip or muck-away lorry, with the paving boarded over first.
Sources: Camden Council: skip licence, Camden: Camden Town Conservation Area Appraisal and Management Strategy (adopted 4 October 2007)
Basement questions for Camden Town
How big can a basement be under Policy A5?
A single storey that is not under an existing basement and covers no more than half of any garden.
Is a basement ever permitted development in Camden?
No. Since 1 June 2017 an Article 4 Direction has made every basement or lightwell dig a planning application.
Will Camden accept a basement facing the road in Camden Square?
Basement work fronting the highway is something Camden normally resists in that conservation area.
Could a lightwell go in front of a former shop on Murray Street?
Camden says lightwells in front of buildings first built as shops there are likely to be resisted.
Does a basement in a listed house need listed building consent?
It does, whether a new basement or an enlarged one, regardless of the planning position.
Are there tunnels under Camden Square?
Two of them: the Midland Railway's 1860s cut-and-fill tunnels run on a diagonal below Camden Road, the square and the mews.
Sources: Camden Local Plan 2017, Camden Planning Guidance: Basements (January 2021), Camden: Camden Square Conservation Area Appraisal and Management Strategy (adopted 11 March 2011)
Related pages
Sources
- Camden: Camden Town Conservation Area Appraisal and Management Strategy (adopted 4 October 2007)
- Camden: Jeffrey's Street Conservation Area Statement (agreed 19 November 2002)
- Camden: Rochester Conservation Area Statement (agreed 12 December 2001)
- Camden Local Plan 2017
- Camden Planning Guidance: Basements (January 2021)
- Camden: Camden Square Conservation Area Appraisal and Management Strategy (adopted 11 March 2011)
- Camden: Regent's Canal Conservation Area Appraisal and Management Strategy (adopted 11 September 2008)
- GOV.UK: Party walls and building work
- Camden Council: Basement developments and planning applications
- Camden Council: skip licence
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