Camden / City of London
House Extension Architects in Holborn
We design house extensions for freehold Holborn townhouses on the Camden / City of London edge — professional streets where authority, leasehold complexity and rear interventions dominate.
Last updated
- Clear fixed fees from £395
- Free, no-obligation consultation
- Licence to Alter drawings
- Extensions, lofts & planning applications
The short answer
Can you extend a house in Holborn?
Yes on freehold Holborn houses that control the rear elevation — subject to the correct authority (Camden or City), conservation checks and freeholder consent on multi-lease buildings.
Planning at a glance
Holborn
| Local planning authority | London Borough of Camden and the City of London (Holborn is predominantly Camden, with only its eastern fringe in the City) |
|---|---|
| Conservation area | Bloomsbury Conservation Area, with the Hatton Garden and Kingsway conservation areas covering the eastern and south-western edges (Camden side) — appraisal adopted Camden designations: Hatton Garden December 1968, Kingsway June 1981, Bloomsbury March 1984 |
| Article 4 direction | In effect since Camden side: 1 June 2017 (basement direction) |
| Likely approval route | Householder planning application or permitted development, depending on conservation status, listing and property type — confirmed for the exact address before drawings begin |
| Statutory determination time | 8 weeks for most householder applications (13 weeks for major applications) |
| Local planning note | Most of built Holborn sits in Camden (Bloomsbury, Hatton Garden and the Kingsway/Aldwych edge); only the fringe around Holborn Circus and Holborn Viaduct reaches the City of London. |
| Typical drawing package | £2,250–£3,250 inc. VAT, fixed fee. Find my package → |
Holborn extensions succeed only on freehold houses that control the rear elevation. Stock includes townhouses and converted professional buildings. Flats and multi-lease conversions stall at ownership. We classify first.
Camden or the City of London must be fixed per address. Authority errors invalidate applications. Conservation coverage and flat status commonly remove PD. We confirm the WC1/EC1 edge address before assuming either council’s process.
Leasehold and freeholder complexity is the Holborn filter. Professional buildings converted to residential often need freeholder packs beside planning. Rights are mapped before design fees.
Rear and roof interventions over street elevations. We keep public frontages calm and test rear projection against neighbour daylight and any mews court.
Party wall notices on terrace flanks and internal divisions of converted houses are programmed with drawings. Construction access on professional streets is a design input.
Steel openings, drainage and multi-storey fire escape must be coordinated early. Open-plan ground floors that destroy protected stairs are redesigned before planning issue.
Holborn’s Camden/City edge is the first drawing decision — a wrong authority on the location plan fails validation before design is read.
Compared with Bloomsbury’s garden-square grain, Holborn more often mixes professional freeholders with residential townhouses.
Farringdon-edge and Temple-edge streets need different access and heritage narratives.
Roof interventions appear more often than deep rear gardens on constrained Holborn plots — we test both routes honestly.
Converted professional buildings may still look like houses on the street but fail householder rights on title.
We write design statements to the correct appraisal for the address, not a generic WC1 paragraph.
A Holborn package sequences authority, title, daylight sections, party wall mapping and householder drawings before joinery is specified.
If the client only controls a flat, we redirect to Licence to Alter and interior works.
Holborn’s Camden or City authority is the first line of the planning package; we do not write a generic WC1 statement and hope the address matches.
Converted professional buildings that look like houses on the street often fail freehold garden control — we redirect those briefs to Licence to Alter early.
Roof interventions on constrained Holborn plots are tested honestly against rear garden depth so clients are not sold a householder extension that cannot exist.
Holborn professional streets need authority, title and rear rights confirmed together — a Camden statement on a City address wastes a planning cycle.
Holborn authority is Camden or City depending on the address; we print the correct council on the location plan before any design statement is written.
Converted professional buildings that look residential on the street still fail freehold garden control more often than true townhouses.
Roof interventions are tested honestly against constrained rear plots so clients are not sold garden depth that does not exist.
Holborn house extensions start with authority and title together — Camden versus City is not a detail left to the location plan at the last minute.
Professional-street access and converted freeholds reshape programme as much as rear depth; we design both into the first package.
We refuse householder fees where the address is a multi-lease professional conversion without rear garden control.
For Holborn, projection depth is set by garden amenity and neighbour daylight in section — not by maximising floor area first and defending it later.
A Holborn extension should join the original wall cleanly; we detail junctions so the addition does not compete with the host façade or conservation reading.
Holborn programmes sequence planning (where required) with party wall awards and building regulations so the build package is contractor-ready, not planning-only.
Thinking about a project in Holborn?
Send the address and a short description. We will confirm the likely approval route and the drawings your project needs.
Local planning
Planning & conservation context
For Holborn we confirm PD versus full application on the exact address — conservation coverage and previous extensions commonly remove the simple rear-extension PD route.
On Holborn streets, foundation proximity and boundary works make Party Wall etc. Act notices routine alongside Camden / City of London drawings.
Conservation coverage in Holborn is address-specific; we do not copy a neighbour's materials without checking the map.
For Holborn, street-facing change is scrutinised harder than hidden rear work — we keep public elevations calm where designation applies.
For the wider local-authority picture — policies, timescales and application routes — see planning in Camden.
Services
Architectural services in Holborn
Extensions & Renovations
Leasehold & Licence to Alter
Nearby
Nearby House Extension Architects pages
Architecture in Holborn: FAQs
Do I need planning permission for a house extension in Holborn?
How far can my Holborn extension project into the garden?
Can I build a two-storey rear extension in Holborn?
Will the Party Wall Act apply to my Holborn extension?
Does a conservation area stop extensions in Holborn?
Is Holborn planned by Camden or the City?
Can I extend a Holborn house converted into flats?
What drawings do I need after planning for a Holborn extension?
How long does a Holborn house extension take to design and approve?
How much do house extension design fees cost in Holborn?
Planning a house extension in Holborn?
Send your Holborn address and a short description of the extension. We will confirm the Camden / City of London planning position, ownership constraints and the drawings your project will need.