Loft bathrooms in Isleworth

Postcode districts: TW3, TW5, TW7
Nearby: Hounslow, Heston and Southall
Guide price: £8,100–£16,250
Typical time on site: 6–12 working days
Water: Very hard across most of Greater London
Survey: Free, at your home

What does a loft bathroom cost in Isleworth?

Our guide price for a loft bathroom in Isleworth is £8,100–£16,250 including VAT. We adjust the national guide for London, where prices are typically about 25% above the UK average. The figure depends on the size of the room, whether anything moves, and the products you pick.

Refit

£6,900–£10,500

Shower, basin and WC replaced

Typical

Signature

£10,000–£16,250

Pump or macerator where needed

New loft bathroom

£12,500–£22,500

Formed in an existing loft room

Guide prices for Isleworth including VAT. Your itemised written quote after the free survey is the price that counts.

Working in Isleworth

As well as Isleworth itself (TW3, TW5 and TW7), we survey in Hounslow, Heston and Southall.

London homes in Isleworth often mean stairs, permits and neighbours below; we plan the logistics as carefully as the bathroom. If your Isleworth loft conversion has a bedroom but no bathroom, the survey starts with where the soil stack runs and how much headroom you have. If your Isleworth house has a combi boiler, a loft shower can usually run on mains pressure without a pump.

Supplies across most of Greater London are very hard. If your supply in Isleworth is the same, limescale on shower glass and heads is a real issue: easy-clean glass, rub-clean nozzles and a squeegee make a big difference. Hardness varies street by street, so check the figure for your postcode with your water supplier.

What the job includes

A check of your hot-water system and of the pressure and flow you actually get at loft level
A shower pump on a gravity system, an electric shower, or advice on moving to mains pressure, depending on your system
Fitted furniture made to the eaves, so the low space behind the slope becomes storage
A drainage route from the loft to the soil stack with enough fall, or a pumped waste or macerator where the rules allow it

Decisions to make first

Bath or no bath

A bath under the slope makes good use of low space, but the floor has to carry it when it is full of water and someone is in it.

Getting the water pressure

A pumped shower suits a gravity system with a cold tank; an electric shower heats cold mains water at the point of use; a combi or unvented cylinder gives mains pressure throughout.

Rules that apply in England

In England, new drainage and a new connection to the soil stack fall under Part H, a new bathroom needs extract of 15 litres per second intermittent or 8 litres per second continuous under Approved Document F, and new circuits are notifiable under Part P. If the work includes an unvented hot-water cylinder, it must be fitted by a G3-qualified installer.

More about loft bathrooms

Loft bathrooms in Isleworth: questions

How much should I budget for a loft bathroom in Isleworth?

A loft bathroom in Isleworth usually costs £8,100–£16,250 including VAT. Expect the lower end for a like-for-like job with standard products, and the upper end if things move or you choose premium finishes. Your quote is itemised and fixed in writing once agreed.

Who handles building control for a loft bathroom in Isleworth?

Building control for Isleworth is handled by the local council or an approved inspector. If your job needs sign-off — for example a new circuit, new drainage or a new extractor where there was none — we tell you at the survey and handle the notification as part of the work.

How long does a loft bathroom take?

Allow 6–12 working days on site for most jobs, plus the lead time for products after you approve the quote. We give you a day-by-day plan before work starts in Isleworth.

Is the home survey in Isleworth really free?

Yes. We visit, measure the room, check the pipework, drainage and electrics, and talk through what you want. You then get a written, itemised quote with no obligation to go ahead.

Is a bath too heavy for a loft floor?

A standard acrylic bath is usually fine on a loft floor built for a conversion, but a filled bath with someone in it is heavy, and stone-resin or cast-iron baths are much heavier still. We check the joist size, span and direction at the survey, and a heavy bath may need a structural check and strengthening first.