House Extensions in Marylebone, W1
Rear, side-return, wraparound and double-storey extensions for houses in Marylebone, designed, approved and built by one team.
Covered under one contract
- Architectural and structural design
- Planning or lawful development certificate
- Foundations, walls, roof and steels
- Glazing, rooflights and doors
- Kitchen designed and fitted
- Building control and party wall handled
House Extensions in Marylebone.
An extension is the surest way to get the open-plan kitchen and dining room most families want, and the houses in Marylebone generally lend themselves to it: a side return to fill, a rear garden to build into, or on larger plots room for a full-width or double-storey addition.
We design the extension around how you will use it, not around the maximum footprint the rules allow. That means thinking about light, the level change to the garden, where the kitchen sits, how the old and new parts of the house meet and what happens to the rooms you already have. The structural engineering, party wall matters and building control inspections are all handled by us.
Approvals are checked on the first visit. Many single-storey rear extensions fall within permitted development, but the City of Westminster applies tighter rules in conservation areas and to flats and listed buildings, so we confirm the route before any drawings are produced and then manage the application if one is needed.
- Area
- Marylebone, W1 · NW1
- Council
- City of Westminster
- Housing
- Georgian and early Victorian terraces, mews houses, mansion blocks and converted flats
- Transport
- Baker Street, Marylebone, Bond Street
- Rear or side return, on site
- 10 to 16 weeks
- Design and approvals
- 8 to 14 weeks before start
- Glazing lead time
- 6 to 10 weeks, ordered early
- Consent
- Permitted development or householder application
- Party wall
- Notices served by us
Marylebone: the houses and the planning rules.
Marylebone is where Space Cucina started, as a kitchen company on Seymour Place. The district is a grid of Georgian and early Victorian streets laid out by the Portman and Howard de Walden estates: flat-fronted brick terraces, stucco around the squares, mews houses behind, and the great mansion blocks of Marylebone Road and Baker Street.
Most of the housing is now flats, from mansion-block apartments to lateral conversions across two houses, which makes refurbishment here as much about approvals and logistics as about design: licences to alter, estate consent, parking suspensions and lift access all shape the programme. We have refurbished bathrooms on Marylebone Road and fitted kitchens for clients across the district.
The Portman Estate, Harley Street and Dorset Square conservation areas cover almost all of it.
Westminster City Council
Applications go to Westminster. Almost the whole district is within conservation areas, and many terraces are Grade II listed, so internal changes to listed houses need listed building consent.
Estate consent
On the Portman and Howard de Walden estates, the freeholder's own approval is needed in addition to planning, with their own design guidance for windows, roofs and rear elevations.
Mansion flats
Block rules govern working hours, deliveries and noise. We plan the programme around them and coordinate with the managing agent.
Approvals for house extensions in Marylebone.
Many single-storey rear extensions are permitted development within the 3 or 4 metre limits, or 6 and 8 metres under prior approval. Conservation areas, flats, listed buildings and larger schemes need a householder application, and every extension needs building regulations approval.
Applications go to Westminster. Almost the whole district is within conservation areas, and many terraces are Grade II listed, so internal changes to listed houses need listed building consent.
What house extensions in Marylebone includes.
- Architectural and structural design
- Planning or lawful development certificate
- Foundations, walls, roof and steels
- Glazing, rooflights and doors
- Kitchen designed and fitted
- Building control and party wall handled
From site visit to handover.
- 01
Site visit & consultation
We visit, listen and measure. Brief, budget and constraints understood before any advice is given.
- 02
Design & itemised quote
Our architects and engineers draw the scheme, and from that we provide a transparent, itemised quotation for your approval.
- 03
Planning & approvals
Planning applications, building control and party wall matters handled for you.
- 04
Build, managed weekly
Our own trades, sequenced by a site manager. Progress reported every week.
- 05
Handover & aftercare
Joint snagging walk-through, documentation, and a guarantee on our workmanship.
House Extensions in Marylebone: your questions.
Do I need planning permission for an extension in Marylebone?
Not always. Permitted development covers many single-storey rear extensions on houses, but the City of Westminster removes those rights in some conservation areas, and flats and listed buildings always need an application. We confirm the route at the site visit.
How long does an extension take to build?
Ten to sixteen weeks on site for a single-storey extension once approvals are in place, plus the design and approval period beforehand. Glazing has the longest lead time, so we order it early.
Which parts of Marylebone do you cover?
All of Marylebone and W1 · NW1, including Seymour Place, Marylebone High Street, Montagu Square, Dorset Square, Harley Street, Baker Street, and the neighbouring districts. We are based in London and our teams work across central, north, north-west, west and south-west London.
Our work near Marylebone.
Other services in Marylebone.
House Refurbishment in Marylebone
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Flat Refurbishment in Marylebone
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Structural Alterations in Marylebone
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Loft Conversions in Marylebone
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Basement Conversions in Marylebone
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Kitchen Renovation in Marylebone
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Bathroom Renovation in Marylebone
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Bespoke Joinery & Fitted Furniture in Marylebone
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Architectural & Interior Design in Marylebone
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Planning Permission & Building Regulations in Marylebone
Read moreHouse Extensions across London.
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We will visit, listen and explain what is possible for your property and how it would be approved. No pressure, no sales pitch.