TL;DR — Key Facts
- Build cost per sqm: £2,500 – £3,800 (inner London borough)
- Council planning fee: £548 (householder application, 2026)
- Typical projects: rear extension, side-return, two-storey, wraparound
- Conservation areas: 58 designated areas in Tower Hamlets
- Permitted Development: Restricted by Article 4 in some areas
Extension costs in Tower Hamlets
Once the budget works, the next step is the drawing set: house extensions in Tower Hamlets.
House extension build costs in Tower Hamlets typically range from £2,500 to £3,800 per square metre, reflecting Tower Hamlets's position as an inner London borough. These figures cover the construction cost only and do not include professional fees, planning fees, or VAT.
For most residents the extension question is really a leasehold one, and the cost is dominated by the licence to alter and any structural report the freeholder requires. On the Georgian houses of Spitalfields and Wapping the drivers are heritage: listed building consent, specialist trades, and materials that match a fabric three centuries old. Neither situation prices like a suburban rear extension.
Typical extension costs in Tower Hamlets (build only)
On top of the build cost, you will need architectural drawings. These fees are 30% below typical London architect rates.
What affects extension costs in Tower Hamlets
Tower Hamlets took 563 householder planning decisions in three years, the smallest real caseload in London (MHCLG planning statistics, retrieved 1 September 2026). The explanation is that the borough is overwhelmingly flats - post-war estates, warehouse conversions and towers - and a leaseholder cannot extend a flat. For the minority who own a house, 58 conservation areas and an Article 4 Direction apply, and in Spitalfields and Wapping listed status usually does too.
Conservation areas
Tower Hamlets has 58 designated conservation areas, including Spitalfields, Whitechapel Market, Fournier Street, Tredegar Square, Wapping Pierhead. If your property is in a conservation area, Permitted Development rights are restricted, meaning you may need a full planning application (£548 council fee). Conservation area applications also tend to require higher-quality materials and more sympathetic design, which can increase build costs by 10-20%.
Article 4 Directions
Tower Hamlets has Article 4 Directions in place. Article 4 for HMOs borough-wide; additional Article 4 covering office-to-residential in Canary Wharf and City Fringe. Where Article 4 applies, works that would normally be Permitted Development require a full planning application. This adds £548 to the council fee and typically 2-3 months to the project timeline, which can affect overall costs if you are renting alternative accommodation during the build.
Property type
The housing stock in Tower Hamlets is predominantly georgian in spitalfields and wapping; victorian industrial conversions; extensive post-war social housing; modern high-density towers in canary wharf and aldgate. Victorian and Edwardian terraces typically suit side-return and rear extensions, while 1930s semi-detached properties are well suited to two-storey rear extensions. Detached houses offer the most flexibility but often have larger footprints, meaning higher absolute costs even if the per-sqm rate is similar.
Access and logistics
Spitalfields and Wapping are Georgian terrace on narrow historic streets, with no side access and severe constraints on deliveries and skip placement. Elsewhere the residential stock is in blocks where the relevant ground is common parts. The practical alternative to an extension for most residents here is internal reconfiguration, which on a listed building needs consent in its own right.
Our drawing fees for Tower Hamlets extensions
At Architectural Drawings London. No hourly billing, no surprises. Our fees cover everything needed for a valid planning submission to Tower Hamlets Council and for building regulations approval.
Drawing fees for extensions in Tower Hamlets
Every package includes a measured survey of your existing property, existing floor plans and elevations, proposed floor plans and elevations, a site plan, and a design and access statement where required. Our MCIAT chartered architectural technologists handle the full process from survey to submission, and we liaise with Tower Hamlets Council on your behalf.
We cover all Tower Hamlets postcodes: E1, E2, E3, E14.
Planning vs Permitted Development in Tower Hamlets
Many house extensions in Tower Hamlets can be built under Permitted Development (PD) rights without needing a planning application. Under PD, single-storey rear extensions can extend up to 6 metres from the original rear wall for terraced and semi-detached houses, or 8 metres for detached houses (under the Prior Approval process). However, Tower Hamlets has Article 4 Directions that may remove some PD rights. Article 4 for HMOs borough-wide; additional Article 4 covering office-to-residential in Canary Wharf and City Fringe.
Fifty-eight conservation areas cover Tower Hamlets, third-most in London, but for most residents the restrictions are moot: the borough is overwhelmingly flats, which never held permitted development rights. On the Georgian houses of Spitalfields and Wapping the materials rule governs, and listed status usually applies as well, reaching the inside of the building.
Two-storey extensions require permission, but they are not what most residents here can do. The borough's housing is overwhelmingly flats, and a leaseholder cannot extend a building they do not own. For the Georgian houses of Spitalfields and Wapping, listed status usually applies alongside the conservation designation, and consent then covers the interior of the building as well as its outside.
The council issued 399 certificates of lawful development in three years (MHCLG planning statistics, retrieved 1 September 2026). The count is low for a straightforward reason: flats have no permitted development rights under Schedule 2, Part 1 of the Town and Country Planning (General Permitted Development) (England) Order 2015, so for most of this borough's residents there is nothing a certificate could confirm.
Frequently asked questions
How much does a house extension cost in Tower Hamlets?
Build costs for a house extension in Tower Hamlets typically range from £2,500 to £3,800 per square metre, as Tower Hamlets is an inner London borough. A typical single-storey rear extension of 15-20 sqm would cost between £37,500 and £76,000 for the build alone. On top of build costs.
Can I extend under Permitted Development in Tower Hamlets?
Fifty-eight conservation areas, third-most in London, concentrated in tight historic pockets rather than spread evenly. In Spitalfields and Wapping the Georgian frontages are among the most closely controlled in the country and listed status is common, so consent reaches internal work. For the borough's many flat-dwellers the restrictions are moot: there were no permitted development rights to remove.
How long does a house extension take in Tower Hamlets?
A typical house extension project in Tower Hamlets takes 5-8 months from initial instruction to completion. This breaks down as: 2-3 weeks for measured survey and drawing preparation, 8 weeks for planning determination by Tower Hamlets Council (if required), 2-4 weeks for building regulations approval, and 8-16 weeks for construction depending on the size and complexity of the extension.
Do I need a Party Wall Agreement for an extension in Tower Hamlets?
Flats are covered by the 1996 statute no less than houses are, so structural work to a dividing wall or floor has to be notified even within a block. On a Spitalfields house the ordinary terraced position applies: two adjoining owners, a month for excavation notices and two for work to the wall. Either way the lease terms are settled before the Act becomes the live question.
What experience do you have with extensions in Tower Hamlets?
We prepare extension drawings for properties across all Tower Hamlets postcodes (E1, E2, E3, E14). Our MCIAT chartered architectural technologists understand Tower Hamlets Council's policies, design guides, and local precedents. We have a council-ready drawing review across all 33 London boroughs.
