Loft Conversions in Harrow, HA1
Dormer, hip-to-gable and mansard loft conversions for houses in Harrow: a bedroom and bathroom under the roof, designed and built by one team.
Covered under one contract
- Structural design and calculations
- Planning or lawful development certificate
- New staircase, dormer and roof windows
- Insulation, fire safety and building control
- En-suite designed and fitted
- Waterproofing with guarantee for basements
Loft Conversions in Harrow.
A loft conversion adds a bedroom and bathroom without touching the garden, and in most of Harrow it is the most cost-effective way to gain a floor. Which type suits your house depends on the roof: Victorian and Edwardian terraces usually take a rear dormer, 1930s semis with hipped roofs need a hip-to-gable conversion to make the space usable, and in conservation areas a mansard or rooflight scheme may be the only option.
We start by measuring the roof. About 2.2 metres from the top of the joists to the ridge is needed for a comfortable room; we check this at the first visit before anything is drawn. From there our architects design the layout and the stair, our engineers design the new floor and any steelwork, and our team builds it with the house occupied throughout.
Most lofts are permitted development within the 40 or 50 cubic metre allowance, with the dormer at the rear. Flats, listed buildings and streets with Article 4 directions need a planning application, and every loft needs building regulations approval for the structure, fire escape and insulation. We manage all of it.
- Area
- Harrow, HA1 · HA2
- Council
- London Borough of Harrow
- Housing
- 1930s semi-detached and detached houses, Victorian and Edwardian houses on the Hill, inter-war terraces around Rayners Lane and North Harrow
- Transport
- Harrow-on-the-Hill (Metropolitan), Rayners Lane, North Harrow
- Loft, on site
- 8 to 12 weeks
- Headroom needed
- About 2.2 m at the ridge
- Consent
- Often permitted development for lofts
Harrow: the houses and the planning rules.
Harrow is Metroland: the streets around Harrow-on-the-Hill, North Harrow and Rayners Lane were built between the wars for commuters on the Metropolitan line, with generous semi-detached houses on plots that suit rear extensions and loft conversions. On the Hill itself, the village around the school is older, with Victorian and Georgian houses inside a conservation area.
It is one of our busiest areas. We have built a rear extension with bi-fold doors and a new kitchen in Rayners Lane, a loft and six-metre rear extension in Harrow on the Hill, refurbished a house in North Harrow, and fitted out cafés in St George's shopping centre and at the bus station.
The Harrow on the Hill Village and Roxeth Hill conservation areas cover the Hill; most of the borough is unrestricted.
London Borough of Harrow
Harrow decides applications. Outside the Hill's conservation areas, most rear extensions and loft conversions fall within permitted development, subject to the usual size limits.
Permitted development
Single-storey rear extensions up to 3 metres, or 6 metres with prior approval, and rear dormers within 50 cubic metres are typical. A lawful development certificate is worth obtaining for resale.
Harrow on the Hill
Within the village conservation area, extensions and roof changes need a planning application and matching materials.
Approvals for loft conversions in Harrow.
Most loft conversions are permitted development within the 40 cubic metre allowance for a terrace or 50 for other houses, with the dormer at the rear. Conservation areas, flats and front dormers need a planning application, and every loft needs building regulations approval.
Harrow decides applications. Outside the Hill's conservation areas, most rear extensions and loft conversions fall within permitted development, subject to the usual size limits.
What loft conversions in Harrow includes.
- Structural design and calculations
- Planning or lawful development certificate
- New staircase, dormer and roof windows
- Insulation, fire safety and building control
- En-suite designed and fitted
- Waterproofing with guarantee for basements
From site visit to handover.
- 01
Site visit & consultation
We visit, listen and measure. Brief, budget and constraints understood before any advice is given.
- 02
Design & itemised quote
Our architects and engineers draw the scheme, and from that we provide a transparent, itemised quotation for your approval.
- 03
Planning & approvals
Planning applications, building control and party wall matters handled for you.
- 04
Build, managed weekly
Our own trades, sequenced by a site manager. Progress reported every week.
- 05
Handover & aftercare
Joint snagging walk-through, documentation, and a guarantee on our workmanship.
Loft Conversions in Harrow: your questions.
Is a loft conversion in Harrow permitted development?
Often, provided the added volume is within 40 cubic metres for a terrace or 50 for other houses and the dormer is at the rear. Flats, listed buildings and streets with Article 4 directions need an application to the London Borough of Harrow.
How much headroom do I need for a loft conversion?
About 2.2 metres from the top of the ceiling joists to the ridge. Victorian and Edwardian roofs usually have it; 1930s hipped roofs often need a hip-to-gable conversion to make the space usable. We measure at the first visit.
Which parts of Harrow do you cover?
All of Harrow and HA1 · HA2, including Rayners Lane, Pinner Road, Harrow View, Roxeth Hill, High Street, Harrow on the Hill, Station Road, and the neighbouring districts. We are based in London and our teams work across central, north, north-west, west and south-west London.
Our work near Harrow.
Other services in Harrow.

House Refurbishment in Harrow
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Flat Refurbishment in Harrow
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House Extensions in Harrow
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Structural Alterations in Harrow
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Basement Conversions in Harrow
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Kitchen Renovation in Harrow
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Bathroom Renovation in Harrow
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Bespoke Joinery & Fitted Furniture in Harrow
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Architectural & Interior Design in Harrow
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Planning Permission & Building Regulations in Harrow
Read moreLoft Conversions across London.
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We will visit, listen and explain what is possible for your property and how it would be approved. No pressure, no sales pitch.



