House
extensions
in Regent's Park, NW1
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Hampstead Chartered Surveyors & Building ConsultancyFew Regent's Park houses can be extended: the terraces are listed, the gardens are protected open space and the rear elevations are on show.
Camden's appraisal finds little scope for new building in its part of the area and asks that new work follow the character, scale, building lines and materials around it.
We say plainly at the first visit when an extension is unlikely, and show what the existing rooms could do instead.
Source: Camden: Regent's Park Conservation Area Appraisal and Management Strategy (adopted 11 July 2011)
Why most terrace houses stay at their size
Section 7 of the listed buildings Act forbids extending a listed building in a way that affects its character without authorisation.
Westminster lists the terraces encircling the park at Grade I.
Camden expects proposals to address the repeated terraced forms and the roof line and rhythm of the historic pattern.
Back elevations are easily seen here, and Camden's appraisal records changed rear windows and added roof terraces.
On a Grade I terrace we do not offer a rear extension as a likely outcome. We look at reusing a mews, a vault or an underused room first.
Sources: Planning (Listed Buildings and Conservation Areas) Act 1990, section 7, Westminster City Council: Regent's Park conservation area information leaflet (May 2004), Camden: Regent's Park Conservation Area Appraisal and Management Strategy (adopted 11 July 2011)
Gardens and open space
Development that loses private open space is unlikely to be acceptable, Camden says.
Corner and other prominent rear gardens need particular care.
The appraisal records pressure to build on the green space around St Katherine's.
In front of the terraces, any basement must keep or reinstate the landscaping, and none is allowed where it would affect large mature trees.
We plot the root protection areas of trees on and next to the plot before any outline is drawn.
Source: Camden: Regent's Park Conservation Area Appraisal and Management Strategy (adopted 11 July 2011)
The Park Villages and later houses
Gardens and a rural feel are integral to the Park Villages, and gaps between houses give glimpses of the green setting.
Camden's guidance wants rear extensions subordinate to the house in form, footprint and detail.
A reasonable garden should remain, and side extensions are normally single storey.
Proposals must pass Camden's 45 and 25 degree tests, or a daylight test.
For an unlisted or later house, we model the addition against the neighbours' windows before we discuss its look.
Sources: Camden: Regent's Park Conservation Area Appraisal and Management Strategy (adopted 11 July 2011), Camden Planning Guidance: Home Improvements (January 2021)
Extensions on Westminster's side
Westminster's City Plan expects extensions to be subordinate and to respect the scale, detailing and materials of the host and its neighbours.
Its Policy 7 guards against harm to daylight, sense of enclosure, privacy and overlooking.
Regent's Park itself is Metropolitan Open Land, protected as green belt is, and development affecting the Royal Parks should enhance them.
Where a garden backs on to the park, we treat the view from the park as part of the design brief.
Source: Westminster City Plan 2019-2040 (2026, adopted January 2026)
Permitted development rarely applies
In a conservation area, cladding, extending beyond a side wall and rear extensions over one storey are not permitted development.
Householder permitted development does not cover flats at all.
Listed building consent is a separate consent from planning permission.
We set out each consent an addition would need, and who grants it, before any money is spent on design.
Sources: MHCLG: Permitted development rights for householders, Technical Guidance (September 2019), Camden Council: Listed buildings
Making more of the rooms you have
The mews behind the terraces were built for stabling and coach houses, and many are now homes.
Camden weighs pressure for better energy efficiency against historic character, so internal upgrades must be chosen with care.
Moving a kitchen downstairs, reusing a vault as a utility room or rearranging a dressing room often wins the space an extension would have given.
Source: Camden: Regent's Park Conservation Area Appraisal and Management Strategy (adopted 11 July 2011)
A plan built round open land
Nash's 1811 plan showed forty villas in the park, cut to eight by 1827, leaving more of it open.
Westminster records Regent's Park as a Grade I registered park, also designated Metropolitan Open Land.
Camden's appraisal says the private gardens between park and terraces, some raised and some sloped, give scale and enclosure through their larger trees.
Because the open land is part of the design, we treat even a garden room or a store as a change to that setting and check it with the council first.
Sources: Westminster City Council: Regent's Park conservation area information leaflet (May 2004), Camden: Regent's Park Conservation Area Appraisal and Management Strategy (adopted 11 July 2011)
Front gardens and boundaries
Camden resists demolishing original boundary walls and encourages front gardens lost to parking to be reinstated.
It records privacy screens fixed behind railings in place of hedges or shrubs.
Bin stores belong in rear gardens if at all possible, and a front store must be carefully sited.
Where privacy is the real need, we suggest planting behind the railings rather than a screen that changes the front.
Source: Camden: Regent's Park Conservation Area Appraisal and Management Strategy (adopted 11 July 2011)
The backs of the terraces and the mews behind
Behind the tall stucco fronts sit low, stock-brick mews that follow the linear plan.
Chester Place shows how the backs were built: brick rear elevations entered from Albany Street.
Camden asks every proposal to respect both its own conservation area and Westminster's next door.
Any addition at the rear sits between a listed house and a listed mews, so we draw the space between the two in section before suggesting a footprint.
Often the better answer is to give the yard back its light: a cleaned and repaired lightwell wall, a new door in an existing opening and a glazed roof light that cannot be seen from the street.
Source: Camden: Regent's Park Conservation Area Appraisal and Management Strategy (adopted 11 July 2011)
Questions about house extensions in Regent's Park
Can I extend a Grade I terrace house?
Only with authorisation, and changes that affect the building's character are prohibited without it.
Is a rear extension permitted development here?
Not beyond one storey in a conservation area, and never for a flat.
Can I build in my garden?
Camden says losing private open space is unlikely to be acceptable.
What does Camden expect of an extension that is allowed?
It should stay subordinate to the house, with a reasonable garden left.
Does the park itself affect what I can build?
Yes. Westminster protects Regent's Park as Metropolitan Open Land.
Sources: Planning (Listed Buildings and Conservation Areas) Act 1990, section 7, MHCLG: Permitted development rights for householders, Technical Guidance (September 2019), Camden: Regent's Park Conservation Area Appraisal and Management Strategy (adopted 11 July 2011), Camden Planning Guidance: Home Improvements (January 2021), Westminster City Plan 2019-2040 (2026, adopted January 2026)
Related pages
Sources
- Camden: Regent's Park Conservation Area Appraisal and Management Strategy (adopted 11 July 2011)
- Planning (Listed Buildings and Conservation Areas) Act 1990, section 7
- Westminster City Council: Regent's Park conservation area information leaflet (May 2004)
- Camden Planning Guidance: Home Improvements (January 2021)
- Westminster City Plan 2019-2040 (2026, adopted January 2026)
- MHCLG: Permitted development rights for householders, Technical Guidance (September 2019)
- Camden Council: Listed buildings
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