Loft conversion cost in Hackney (2026)
A loft conversion with a rear dormer on a two-storey mid-terrace house in Hackney typically costs £66,000 to £104,000 all in: the build and the professional and council fees, including VAT, with about £8,500 contingency to hold back on top. The build alone is £53,000 to £89,000, about £2,500 per m² for 28 m².
Likely cost, all in
£66,000 to £104,000
Expected about £85,000. With the contingency, have £112,000 available.
Mostly Victorian terraces and Georgian townhouses, many split into flats, alongside postwar estates and converted warehouses. Build rates in Hackney run about 5% above our London baseline, for parking, access and labour.
A loft conversion turns the roof space into a bedroom, usually with an en suite. A rear dormer is the common London job; hip-to-gable suits semis and end-terraces with a hipped roof; a mansard rebuilds the roof as an extra storey and needs planning permission. The staircase, the steels and the head height decide most of the price.
Typical all-in totals in Hackney
For a two-storey mid-terrace house of the usual size, before extras such as a new kitchen, bathroom or bifold doors. Including VAT.
| Job | Straightforward | Good quality | High end |
|---|---|---|---|
| Loft conversion with rooflights onlyabout 20 m² | £44,000 to £72,000 | £48,000 to £78,000 | £58,000 to £93,000 |
| Loft conversion with a rear dormerabout 28 m² | £61,000 to £96,000 | £66,000 to £104,000 | £79,000 to £123,000 |
| L-shaped dormer loft conversionabout 36 m² | £74,000 to £115,000 | £81,000 to £125,000 | £96,000 to £148,000 |
| Hip-to-gable loft conversionabout 34 m² | £73,000 to £110,000 | £79,000 to £120,000 | £94,000 to £142,000 |
| Mansard loft conversionabout 40 m² | £103,000 to £155,000 | £111,000 to £167,000 | £130,000 to £195,000 |
Where the money goes: a loft conversion with a rear dormer, good-quality finish
The build
- Loft conversion: structure, stairs, roof, insulation, windows, first and second fix£53,000 to £88,500
Fees and permissions
- Architect or designer: drawings, planning and building regulations package£4,000 to £11,500
- Structural engineer: calculations and beam design£1,000 to £2,500
- Lawful development certificate (advised)£359
- Building control: plan check and inspections£1,000 to £1,500
- Party wall surveyors (2 neighbours, if they dissent)£0 to £6,000
Likely cost, all in£66,500 to £104,000
Contingency to hold back£8,500
Budget to have available£112,500
All figures include VAT at 20%. Builders often quote without VAT, so add 20% to any quote that says 'plus VAT' before comparing it with this report.
Planning permission in Hackney
For this job on a house outside a conservation area: Likely permitted development (no planning application)
- ? checkRoof volume allowance. Dormers and gables may add up to 40 m³ to the roof of a terraced house, counting any earlier roof additions. A rear dormer across a London terrace is usually 30 to 45 m³, so measure before assuming.
- ? checkNot on the front. No part may extend beyond the plane of the roof slope that fronts a highway.
- ? checkSet back from the eaves. A dormer must sit at least 20 cm back from the original eaves, measured along the roof slope, and no higher than the existing ridge.
- ? checkSide windows. Any side-facing window must be obscure-glazed and non-opening below 1.7 m from the floor.
The full report checks the planning register at your postcode for conservation areas, Article 4 directions, flood zones and listed buildings nearby, which change the answer street by street. The decision is London Borough of Hackney's: their website has the local validation list and any supplementary guidance on extensions. Fees are the national statutory figures.
How long it takes
From first sketch to sign-off, about 23 to 39 weeks, of which 6 to 10 on site.
- Design and drawings4 to 8 weeks
- Lawful development certificate8 to 10 weeks
- Structural design, building regulations drawings, tender4 to 8 weeks
- Party wall notices4 to 10 weeks
- Build6 to 10 weeks
- Completion and sign-off1 to 3 weeks
Questions people ask
- How much does a loft conversion cost in Hackney?
- A loft conversion with a rear dormer on a two-storey mid-terrace house in Hackney typically costs £66,000 to £104,000 all in, including VAT. The building work itself is £53,000 to £89,000; the rest is professional and council fees. Hold back about £8,500 more as a contingency. A high-end finish, a bigger footprint or a new kitchen move the figure up; the table on this page shows the range for each variant and finish.
- Do I need planning permission for a loft conversion in Hackney?
- For a loft conversion with a rear dormer on a house outside a conservation area, the usual answer is: likely permitted development (no planning application). Rear dormers and rooflights are usually permitted development within the roof volume allowance; a mansard, or any loft in a conservation area, needs a planning application. Whether your street is covered by one of those is checked against the planning register in the full report.
- How long does a loft conversion take in Hackney?
- About 23 to 39 weeks from first sketch to sign-off, of which 6 to 10 weeks are on site. Design, drawings and the council's decision take most of the rest. Builders in London are often booked three to six months ahead, which adds to the calendar but not to the cost.
- What fees are there on top of the builder's price?
- For this job, about £6,500 to £22,000: an architect or designer for the drawings, a structural engineer, building control, any council fee, and party wall surveyors if a neighbour dissents. On top of that, hold back a contingency of about £8,500 for what the ground and the existing house turn up.
- Do these figures include VAT?
- Yes. Every figure on this page and in the report includes VAT at 20%. Builders often quote without it, so add 20% to any quote marked "plus VAT" before comparing.
Your own house
Get the figures for your own house
The numbers above are for a typical house. Your report prices your footprint and finish, reads the public records for your address, checks the planning rules for your street, and lists the questions to ask anyone who quotes. You see what we found before you pay.
Other jobs in Hackney
Loft conversion cost elsewhere in London
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This report is an informed estimate built from public data about your property and current London build costs. It is not a survey, a quote, a valuation or planning advice. Always get written quotes and, where noted, professional advice before committing to work.