Harrow
Loft Conversions in Harrow
Harrow is 1930s semis and Edwardian housing — hip to gable on the inter-war stock, planning-led on the older streets.
Loft Conversions in Harrow, HA1
If you're weighing up a loft conversion in Harrow, the first useful thing to know isn't the price — it's which type of conversion your house is pointing at. That's decided by the roof, and in Harrow the roof is fairly predictable.
Tell us about your property and we'll pass it to loft conversion specialists covering HA1. It takes about two minutes, there's no fee, and nobody is going to sell you anything.
What Harrow Houses Usually Need
Harrow is 1930s semis and Edwardian housing, and it's the second-strongest area in our coverage by search demand after Ealing itself. Hip to gable is the default on the inter-war stock. Harrow on the Hill and the older parts of the borough carry conservation coverage set by Harrow Council, so the answer varies by street more than the housing type alone would suggest.
Loft Conversion Types in Harrow
Not sure which of these describes your house? It's the first thing a surveyor establishes on site, and it's a perfectly normal place to start from. The type guide walks through it in order.
What a Loft Conversion Costs in Harrow
These are West London ranges for a completed conversion — estimates, not quotes.
| Conversion type | Typical range |
|---|---|
| Velux / rooflight | £22,000 – £32,000 |
| Rear dormer | £42,000 – £62,000 |
| Hip to gable | £48,000 – £70,000 |
| Hip to gable with rear dormer | £58,000 – £85,000 |
| L-shaped dormer | £55,000 – £80,000 |
| Mansard | £65,000 – £105,000 |
Harrow's semis price well relative to the rest of West London — the houses are alike, the roofs are predictable, and side access makes the build simpler. The biggest single variable is whether you add a rear dormer to the gable, which is what most people here end up doing. A bathroom adds roughly £5,000 to £9,000.
What to Expect in Harrow
Access
Most Harrow semis have a side passage, which makes materials and waste far easier to move. It's one of the quieter reasons conversions price well here.
Party Walls
On a semi or end-terrace the shared wall is almost always involved. Serve notice at least two months ahead — it's the deadline most likely to hold up a start date.
Planning
Harrow is in Harrow, so its conservation areas and Article 4 directions are set by that council, not Ealing's. The national permitted development rules are the same everywhere; the local designations are not.
Building Regulations
Required on every loft conversion in Harrow, whether or not planning permission is needed. It covers structure, fire safety, the staircase and insulation, and it ends in a completion certificate you'll want when you sell.
The Staircase
Easy to overlook and frequently the thing that shapes the whole design. You need at least 2 metres of headroom over the full flight and landings, and on a narrow house the question of where the stairs land can matter more than the roof itself.
Timing
Six to ten weeks on site for a typical conversion, but four to seven months from first quote to completion certificate once design, party wall notices and any planning application are counted in. If your conversion needs permission, add roughly three months.
How We Work in Harrow
We're a lead service, not a building company — so what we do is narrow, and it's worth being clear about it.
You tell us about your property: the type of house, what you want the space for, and roughly when you'd like to start. We pass that to loft conversion specialists covering HA1 and the surrounding part of Harrow. They come back to you with quotes, and you compare them or you don't.
There's no fee, nothing to buy, and no obligation at any point. A loft conversion is a £30,000–£50,000 decision that essentially nobody makes on one quote. Comparing three isn't a chore we invented — it's what you were going to do anyway. All this does is make the first step take two minutes instead of an afternoon.
Get Loft Conversion Quotes in Harrow
Five questions, two minutes, no obligation.
Harrow Loft Conversion Questions
Do I need planning permission for a loft conversion in Harrow?
Harrow is in Harrow, so conservation areas and Article 4 directions are set by that council. The national permitted development rules are identical everywhere; the local designations aren't.
How much does a loft conversion cost in Harrow?
Most conversions in this part of West London land between £42,000 and £70,000, with rooflight conversions lower and mansards higher. Checkatrade puts the Ealing average at just under £36,000 across all types — that figure is lower because it includes the simplest conversions. These are estimates, not quotes.
Which type of loft conversion suits Harrow houses?
A hip to gable most often, for the reasons above — though the only way to be certain is for someone to look at your actual roof. Plenty of streets have a mix.