Guide · Loft conversion costs
How much does a loft conversion cost in Ilford and East London?
Our starting prices for Velux, dormer, hip-to-gable and mansard lofts, what changes the cost, and the extras that are quoted separately.
Last updated 28 October 2026
Short answer: loft conversions in Ilford and East London start from £32,000 for a Velux (roof-light) loft, from £55,000 for a rear dormer, from £68,000 for a hip-to-gable with rear dormer and from £75,000 for a mansard. These are our own starting prices. Your exact figure depends on your roof, your loft height and the extras below, and we confirm it in writing after a free survey.
Loft conversion prices from SK Design
| Type | Starting price | Notes |
|---|---|---|
| Velux (roof-light) loft conversion | from £32,000 | No change to the roof shape; good where there is enough head height. |
| Rear dormer loft conversion | from £55,000 | The most common loft in Redbridge terraces and semis. |
| Hip-to-gable with rear dormer | from £68,000 | For semis and end-of-terrace houses with a sloping side roof. |
| Mansard loft conversion | from £75,000 | Usually needs planning permission. |
Starting prices, not fixed quotes. No VAT is added because SK Design & Construct Ltd is not VAT registered. The full list is on our prices page.
What decides the cost of a loft conversion?
Two houses on the same street can get very different quotes. These are the factors that move the price most.
- The type of conversion. This is the biggest single factor and the reason the table above has four rows.
- Loft size and head height. More floor area costs more. Low lofts may need a dormer or a lowered ceiling below, which adds work.
- Roof structure. Older houses with traditional rafters convert more easily than later houses with W-shaped trussed rafters, which need more steel.
- Steelwork and floor strengthening. Ceiling joists are built to carry a ceiling, not a bedroom. The floor is normally strengthened.
- The new staircase. It needs a position, head height over each step and a protected escape route.
- Bathroom or en-suite. Plumbing and drainage must reach the loft. See our bathroom fitting page, where shower room refits start from £5,500.
- Finish. Flooring, fitted wardrobes and decorating all change the total.
Velux loft conversion
A Velux conversion keeps the roof shape and adds roof windows in the existing slope. It involves the least structural change, so it has the lowest starting price in our list, from £32,000. The catch is head height. You only get full standing height under the ridge, so it suits houses with a tall, generous roof space. If your loft is shallow, a Velux conversion may not give you a usable room, and we will tell you that at the survey rather than sell you the wrong job.
Rear dormer loft conversion
A box dormer on the back of the house gives full head height across most of the room, plus a straight wall for a window and often an en-suite. It is the most common loft in Redbridge terraces and semis and starts from £55,000. The extra cost over a Velux comes from the new structure, which has to be framed, insulated, made weathertight and tied into the existing roof.
Hip-to-gable loft conversion
Many semi-detached and end-of-terrace houses in Ilford have a hipped roof that slopes away at the side. A hip-to-gable conversion builds that slope up into a vertical gable wall, which gives much more usable space, and it is usually combined with a rear dormer. It starts from £68,000. Because the side wall is rebuilt, the roof structure changes more, and on a semi the wall may be shared, so party wall notices are likely.
Mansard loft conversion
A mansard rebuilds the roof with a steep-sided slope and a flat top. It gives the most space and a very different look. Starting from £75,000, it is the dearest type in our list, and it usually needs planning permission, which adds drawing work and a wait for the council.
Extras that are not in the starting price
Our starting prices cover the building work. These items are separate, and they are shown as their own lines on our written quote so you can see where the money goes.
- Drawings. Architectural plans are needed for Building Regulations and for any planning application.
- Structural engineer. Calculations for steel beams and floor strengthening.
- Building Control. Every loft conversion needs Building Regulations approval, with inspections as work progresses.
- Party wall costs. If you share a wall with a neighbour, notices are served under the Party Wall etc. Act 1996. If a neighbour appoints a surveyor, there may be surveyor fees.
- Planning fees, where permission is needed.
We do not quote a figure for these here because they depend on the house. We list them clearly in your quote after the free survey.
Permitted development or planning permission?
Many loft conversions on houses are permitted development within volume limits, as long as they do not extend beyond the front roof slope. Flats, conservation areas and mansards usually need planning permission. Either way, Building Regulations approval is needed. We explain the limits in our guide: Do I need planning permission for an extension or loft conversion in Redbridge?
Party walls
Most Ilford lofts are on terraced or semi-detached houses. Steel beams normally rest on the shared wall, and a hip-to-gable rebuild can raise it. That is party wall work, so we advise serving notices in good time. Talking to your neighbours early usually makes this smoother.
How to get an accurate price
- Measure the head height from the top of a ceiling joist to the underside of the ridge. About 2.2 m or more is a useful starting point.
- Note your roof shape: terraced, semi with a hip, or end-of-terrace.
- Check whether the loft has a water tank or trussed rafters.
- Call 07774 944042 to book a free survey. We measure the loft, check the planning position and give you a written, itemised quote.
Read more about the work on our loft conversions page. If you are weighing a loft against more ground-floor space, see our house extensions page and the house extension cost guide. If your roof needs work first, see roofing. We cover Ilford, Redbridge, Romford, Barking and the rest of East London and Essex.
Questions people ask
How much does a loft conversion cost in Ilford?
Our starting prices are from £32,000 for a Velux (roof-light) loft, from £55,000 for a rear dormer, from £68,000 for a hip-to-gable with rear dormer and from £75,000 for a mansard. The final figure is confirmed after a free survey with a written quote.
Is a dormer loft conversion much dearer than a Velux?
Yes. A Velux conversion starts from £32,000 and a rear dormer from £55,000, because the dormer builds new structure to gain head height and floor space. Which one suits you depends on your loft height, so we measure it for free.
Are drawings, structural engineer and Building Control included in the starting price?
No. Drawings, structural calculations, Building Control and any party wall costs are separate, and we show them on the written quote. We do not put a figure on them here because they depend on the house.
Do I need planning permission for a loft conversion in Redbridge?
Many house lofts are permitted development within volume limits, but flats, conservation areas and mansards usually need planning permission. Every loft conversion needs Building Regulations approval. Read our planning guide for the detail.
Do I need a party wall agreement for a loft conversion?
On most terraced and semi-detached houses, yes. Steel beams usually rest on the shared wall, and a hip-to-gable rebuild can raise it. Notices go to the neighbours under the Party Wall etc. Act 1996 before work starts.
Does a loft conversion price include an en-suite?
The starting prices do not list an en-suite separately. A shower room or en-suite is planned at survey stage and shown as its own line on the written quote. Our shower room refits start from £5,500.
Visit or contact us
SK Design & Construct Ltd, 6 Spurway Parade, Woodford Avenue, Ilford IG2 6UU. Call or WhatsApp 07774 944042 or email info@skdesignconstructltd.com. Registered in England and Wales, company number 16582978.