Hammersmith & Fulham Extension Data 2026: Costs, Prices & Planning
We analysed 7,616 Land Registry transactions, EPC records, and planning constraint data for Hammersmith & Fulham. With median terraced prices at £1.4 million and 47 conservation areas, this inner London borough offers exceptional extension ROI - but requires careful planning navigation.
TL;DR
Hammersmith & Fulham is prime extension territory. At £1.4M median for a terraced house, even a modest 10% value uplift from a £60-70k extension delivers £140k in added value - a 2-2.3x return. The catch: 47 conservation areas cover a significant portion of the borough, particularly across Fulham, Brook Green, and Brackenbury Village. At 37% freehold, most flat owners face additional freeholder consent costs. For houses though, Hammersmith & Fulham offers some of the strongest extend-not-move economics in London.
£1.4M
Median terraced price
HM Land Registry
37%
Freehold ownership
Land Registry tenure data
47
Conservation areas
planning.data.gov.uk
Band B
GLA value band
London Plan viability study
Sources: HM Land Registry (2023-2026), planning.data.gov.uk, GLA London Plan, Mayfair Studio cost model
Hammersmith & Fulham in Numbers
From 7,616 residential transactions recorded between January 2023 and March 2026, here are the median prices by property type. The remarkably tight gap between detached and semi-detached prices reflects the scarcity of both types in this predominantly terraced and flat-heavy borough.
| Property type | Median price | Context |
|---|---|---|
| Detached | £1,744,000 | Extremely rare - mostly in Fulham and near river |
| Semi-detached | £1,650,000 | Scattered across Brook Green, Ravenscourt Park |
| Terraced | £1,400,000 | The dominant house type - Fulham, Parsons Green, Sands End |
| Flat | £635,000 | Converted Victorians and purpose-built across borough |
Source: HM Land Registry Price Paid Data • Data as of January 2023 - March 2026
Property Profile
Hammersmith & Fulham is defined by its Victorian and Edwardian terraces. EPC data shows the majority of houses are solid-wall construction, built between 1850 and 1910. The classic Fulham terrace - three storeys with a rear addition and small courtyard garden - is the archetypal property here.
Side return extensions are particularly popular in Fulham and Parsons Green, where narrow Victorian layouts benefit enormously from opening up the ground floor. Rear extensions and loft conversions (L-shaped dormers are common) are the other dominant extension types.
Freehold ownership at 37% is low but typical for inner London. The majority of properties are flats in converted Victorian houses or purpose-built blocks, which are leasehold. For terraced house owners - who are predominantly freehold - this is less of a concern.
Planning Constraints
Hammersmith & Fulham has 47 conservation areas - a very high number that places it among the most constrained boroughs in London, alongside Wandsworth (46), Westminster (56), and Southwark (56). Key conservation areas include the Brackenbury Village Conservation Area, the Moore Park Conservation Area, and large sections of Fulham between Parsons Green and Bishop's Park.
The borough has 48 Article 4 directions (sourced from LBHF council website, March 2026). The national planning dataset also records 264 listed buildings and 3 TPO zones for the borough (via spatial query on planning.data.gov.uk). The density of conservation area coverage means that a significant proportion of houses are already covered by heritage constraints that remove most permitted development rights.
For properties within conservation areas, full planning permission is required for most extensions. The council pays particular attention to roof extensions - L-shaped dormers visible from the street are frequently refused. Rear extensions and basement excavations are more commonly approved, subject to design quality and neighbour impact.
Extension Costs in Hammersmith & Fulham
As an inner London borough, Hammersmith & Fulham has a baseline build cost of £3,000/m². GLA value band B classification means specification expectations are high - homeowners in Fulham and Parsons Green expect Crittall-style glazing, composite stone worktops, underfloor heating, and high-end joinery as standard.
| Extension type | Size | Build cost (low) | Build cost (high) |
|---|---|---|---|
| Rear extension | 15m² | £40,500 | £58,500 |
| Rear extension | 25m² | £67,500 | £97,500 |
| Loft conversion | 40m² | £108,000 | £156,000 |
| Side return | 10m² | £27,000 | £39,000 |
Source: Mayfair Studio cost model (inner London, band B) • Data as of 2024/25 rates
Build costs only. All-in costs including kitchen, fees, VAT, and contingency are typically 2-2.5x the build cost. Band B specification uplift may add 5-10% to these baselines.
Cross-Dataset Insights
Combining Land Registry, EPC, and planning data reveals patterns specific to Hammersmith & Fulham:
- 1.The detached-to-semi gap is just £94k - the tightest in London. At £1,744k vs £1,650k, detached and semi-detached homes trade almost identically. This reflects the extreme scarcity of both types: the borough is overwhelmingly terraced houses and flats. When detached properties do appear, they command a premium for rarity rather than size.
- 2.Extension ROI here is among the best in London. A £60-70k rear extension on a £1.4M terraced house can add £140-280k in value (10-20% uplift). Even accounting for higher inner London build costs and potential planning fees, the return on investment is 2-4x the outlay.
- 3.47 conservation areas create a patchwork of PD eligibility. A street in Fulham might have PD rights while the parallel street - within a conservation area - does not. This postcode-level variation is more extreme here than in most outer boroughs, where constraints are either borough-wide or largely absent.
- 4.The flat-to-terrace price gap is £765k. At £635k vs £1.4M, this is one of the largest gaps in London. It underlines why ground-floor flat owners in converted Victorians often explore rear garden extensions - adding outdoor space and square footage to close the gap between flat and house values.
Frequently Asked Questions
How much does an extension cost in Hammersmith & Fulham?
Build costs in Hammersmith & Fulham are approximately £3,000/m² (inner London rate). A 15m² rear extension costs £40,500-£58,500 for the build, with all-in costs including kitchen, fees, and VAT typically reaching £85,000-£145,000. Band B specification expectations push costs higher than outer London equivalents.
Do I need planning permission for an extension in Hammersmith & Fulham?
Many properties in Hammersmith & Fulham fall within one of its 47 conservation areas, which removes most permitted development rights. Outside conservation areas, standard PD rules apply. Our free AI chat checks your exact address against all constraint datasets instantly.
How many conservation areas does Hammersmith & Fulham have?
Hammersmith & Fulham has 47 conservation areas according to planning.data.gov.uk. Key areas include Brackenbury Village, Moore Park, large sections of Fulham, and areas around Brook Green and Ravenscourt Park.
Is a side return extension worth it in Fulham?
Side return extensions are extremely popular in Fulham, where Victorian terraces have narrow rear additions with wasted side passages. A 10m² side return costs approximately £27,000-£39,000 to build and opens up the kitchen-dining space significantly. Given median terraced prices of £1.4M, the ROI is excellent.
What is the average house price in Hammersmith & Fulham?
Based on 7,616 Land Registry transactions (2023-2026), median prices are: detached £1,744,000, semi-detached £1,650,000, terraced £1,400,000, flat £635,000. Prices are highest in Fulham, Parsons Green, and along the river.
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