Hillingdon
Loft Conversions in Hayes
Hayes is inter-war and factory-estate housing built to consistent layouts — unusually predictable to price.
Loft Conversions in Hayes, UB3 & UB4
If you're weighing up a loft conversion in Hayes, 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 Hayes the roof is fairly predictable.
Tell us about your property and we'll pass it to loft conversion specialists covering UB3 & UB4. It takes about two minutes, there's no fee, and nobody is going to sell you anything.
What Hayes Houses Usually Need
Hayes is largely inter-war and former factory-estate housing, built to consistent layouts, which makes conversions here unusually predictable to price. Hip to gable with a rear dormer is the standard answer on the semis. Most of these houses have side access, which keeps the build simpler than an equivalent terrace job.
Loft Conversion Types in Hayes
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 Hayes
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 |
Hayes'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 Hayes
Access
Most Hayes 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
Hayes is in Hillingdon, 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 Hayes, 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 Hayes
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 UB3 & UB4 and the surrounding part of Hillingdon. 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.
Hayes Loft Conversion Questions
Do I need planning permission for a loft conversion in Hayes?
Hayes is in Hillingdon, 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 Hayes?
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 Hayes 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.