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 pin. 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 pin, 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 pin 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 pin wastes a planning cycle.
Holborn authority is Camden or City depending on the pin; 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 pin 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.
