Which postcode districts around City of London do we cover for rear dormer work?
Below, the City's postcode districts one by one: the building type that dominates each, and who validates a roof scheme at an address within it. Figures in that table are the England statutory scale for 2026, paid to the Corporation, and are not dormer pricing.
| Postcode | Area | Dominant stock | What it means for a rear dormer |
|---|
| EC1A | Smithfield | Mostly commercial, residential lofts | EC1A covers Smithfield only; City of London Corporation handles the rear dormer. |
| EC2Y | Barbican | Listed Brutalist apartments (Barbican Estate) | EC2Y covers Barbican only; City of London Corporation handles the rear dormer. |
| EC3N | Tower Hill / Aldgate | Very limited residential — Barbican Estate (listed post-war) | EC3N covers Tower Hill / Aldgate only; City of London Corporation handles the rear dormer. |
| EC4M | St Paul's | Mostly commercial, listed residential | St Paul's sits wholly inside EC4M, so City of London Corporation validates every rear dormer submitted from an EC4M address. |
| EC4V | Blackfriars | Very limited residential — Barbican Estate (listed post-war) | Blackfriars sits wholly inside EC4V, so City of London Corporation validates every rear dormer submitted from an EC4V address. |
| EC4Y | Temple | Very limited residential — Barbican Estate (listed post-war) | A rear dormer at an EC4Y address in Temple is determined by City of London Corporation under its own Local Plan policies for Temple. |
| EC2A | Shoreditch | Warehouse conversions, modern infill | EC2A does not sit wholly in the Square Mile. A Shoreditch address may be determined by Hackney Council or by the City of London Corporation, so establish which of the two holds the file before EC2A drawings are submitted. |
Which City of London neighbourhoods suit a rear dormer best?
The Square Mile is not uniform above eaves level. From one street to the next the pitch changes, the wall build-up changes and so does the ground behind the building, and every variation limits what a rear dormer can be.
- Barbican (EC2Y) — a rear dormer in Barbican starts from listed brutalist apartments (barbican estate), and Barbican reads as Brutalist listed estate. Trussed post-war roofs need a full structural redesign before a dormer in EC2Y. City of London Corporation assesses Barbican rear dormers against its own Barbican character guidance, and the location plan we draw for Barbican references Barbican Centre.
- Smithfield (EC1A) — a rear dormer in Smithfield starts from mostly commercial, residential lofts, and Smithfield reads as Georgian and Victorian commercial. Full-width rear dormers on Victorian terraces here are the default in EC1A. City of London Corporation assesses Smithfield rear dormers against its own Smithfield character guidance, and the location plan we draw for Smithfield references Smithfield Market.
- Fleet Street (EC4) — Georgian and Victorian commercial defines Fleet Street, where mostly commercial, residential conversions set what a rear dormer can do. Full-width rear dormers on Victorian terraces here are the default across EC4. Any Fleet Street rear dormer is validated by City of London Corporation, with Royal Courts of Justice the usual Fleet Street reference point on the site plan.
- St Paul's (EC4M) — rear dormer work in St Paul's means mostly commercial, listed residential. St Paul's is Listed heritage commercial core. Full-width rear dormers on Victorian terraces here are the default throughout EC4M. City of London Corporation decides the St Paul's application, and St Paul's Cathedral anchors the St Paul's location plan.
What local planning policy applies to a rear dormer in City of London?
City of London conservation designations: there are 27 across City of London Corporation, Fleet Street, Whitefriars, St Paul's among them. Designation costs a City of London owner the permitted-development route: a rear dormer then needs a £548 householder application over 8 weeks, in place of the £249 prior approval route that takes 6 weeks. Fleet Street is the City of London designation that most often changes a rear dormer design.
City of London and Article 4: Multiple Article 4 Directions around office-to-residential, demolition, and shopfront changes. A rear dormer planned at a EC1A address is checked against that direction first; City of London Corporation publishes the City of London extent, and the EC1A line rarely follows the City of London boundary you would expect.
The building fabric around City of London: Very limited residential — Barbican Estate (listed post-war), Golden Lane Estate, modern luxury flats; overwhelmingly commercial. Overwhelmingly commercial; residential planning extremely constrained; one of the two highest listed-building densities in London. A rear dormer in City of London is scoped against that stock first, because it decides whether the scheme runs as permitted development, a £274 Lawful Development Certificate, or a full £548 application to City of London Corporation.
Who decides a rear dormer on the edge of City of London?
- Tower Hamlets — cross the City of London boundary and Tower Hamlets Council takes the rear dormer instead, applying 58 conservation areas of its own around E1. We re-price rear dormers at the City of London edge because Tower Hamlets policy and City of London policy rarely align on rear dormer depth.
- Southwark — cross the City of London boundary and Southwark Council takes the rear dormer instead, applying 43 conservation areas of its own around SE1. We re-price rear dormers at the City of London edge because Southwark policy and City of London policy rarely align on rear dormer depth.
- Westminster — adjoining City of London, with 56 conservation areas centred on SW1. A rear dormer on the far side of the City of London line is determined by Westminster City Council, so the City of London quote for rear dormers is checked against Westminster guidance before it is issued.
- Camden — the Camden boundary runs against City of London, so a rear dormer a street from City of London is decided by Camden Council instead. Camden runs 40 conservation areas across NW1 and its neighbours, which is why rear dormers priced for City of London are re-checked against Camden policy whenever the City of London address sits on that edge.
Sources for this City of London rear dormer page: borough policies maps and
conservation-area registers (2025–26), Royal Mail postcode district boundaries,
the Town and Country Planning (Fees for Applications) (England) Regulations, the Town
and Country Planning (General Permitted Development) (England) Order 2015 as amended,
and the Party Wall etc. Act 1996.
