Setting the right budget

How much should you expect to pay?

We know it's difficult to estimate how much a project will cost, that's why we've surveyed our tradesmen to give you an idea of how much you should expect to pay for specific jobs. Tradesmen all across the country have contributed to the cost guides, so the costs you see are an approximate national average.

Install under stairs toilet

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Under stairs toilet £1,000 £3,000

Installing a toilet under the stairs is a great way of using space and can be a useful solution for a growing family or for older homeowners. The area should already be fairly self-contained, so there is not a lot of construction work to do. However, there will still be a fair amount of work to do in terms of plumbing, electrics and ventilation. All of these will need to be up to scratch to comply with building regulations, so it is worth the cost to get an experienced professional in to undertake to job and to coordinate any additional tradesmen that may be needed.

A tradesman will usually visit your home first to look at the space, measure up and work out how best to install a toilet. Not all under stairs areas are suitable for toilets and you will need to have a space that is large enough to stand in or that can be made large enough to stand in. Your under the stairs area may already be enclosed or it may require the erection of a stud wall to close off the under stairs space. The cost of the job overall will depend on the toilet hardware you choose as well as other extras you need, such as a sink, light fittings or ventilation.

Hooking your under stairs toilet up to waste and water supplies

The main part of the job is connecting the toilet to a cold water supply for the flush and to an outlet for waste. You may need to install a new manhole to deal with this, which can considerably add to the cost of the job, as it requires a good deal of prep work and installation. Alternatives such as a Saniflo system can be fitted if you have trouble connecting to the waste outlet ‘soil stack’.

You may also wish to install hot water for a wash basin, which will push up the cost of the job. You will need to run pipes to this area if there are none for the plumber or builder to work from. If you want heating in the toilet you will also have to get your plumber to install a radiator and connect it to your central heating system. Alternatively you could use an electrical heater.

Installing a second toilet under the stairs

You will need to make sure that the area is well-ventilated to comply with building regulations. This may mean cutting a hole in an exterior wall and/or fitting ducting for a fan. You may also want to add a window for natural light or to simply install some new light fittings in the ceiling. The switch for the light can also be set up to switch on the ventilation fan.

Once the job is finished and the toilet is installed you will need to paint and decorate the room, as well as adding carpet or flooring if this is required. Your builder should be able to make sure that the job is completed to building regulations and advise you during the job of the parts of the job that are necessary for your new under stairs toilet to comply with these. Don’t forget to budget for door locks and make sure that there is enough room for the door to open and close adequately so you can enter and exit your new toilet safely.

Rated People surveyed 59 of our registered builders to find out how much it costs to carry out a range of internal renovation work to your home.

Please note these prices are average, do not include materials and offered as guidance only to help you when you post a job on Rated People. For a free quote tailored to your specific requirements, please contact one of our skilled local builders.


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