Geoff Wells, bathroom planning expert for Dolphin Bathrooms, comments:

“There a few key considerations to take into account with this kind of project. Once the gas and electricity meters have been moved by registered professionals, the first point that needs addressing is extraction. Understairs spaces are often located in the centre of the house and because you are looking to create a new environment, you will need to establish an effective extraction route but this shouldn’t be too much of a problem, particularly if the area is adjacent to an external wall.

“Secondly, you need to route both hot and cold water supplies to the room and arrange for waste removal. Where access to the SVP (soil and vent pipe) is difficult a macerator is the best solution as it can pick up the waste from the basin, shower and WC and exit to the SVP in small bore flexible piping.

“Thirdly, to have a shower you will need to have sufficient height, but a bathroom expert can advise you on this. After these points have been addressed, you can consider the space saving solutions available to you. An outward opening door to the shower room is the best way to maximise the space inside whilst opting for a small, wall-mounted wash basin will make efficient use of space and help to keep floor areas open and free.

“Shower trays can be very compact in size – as small as 700mm x 700mm – and depending on the dimensions of the room, you could choose either a bi-fold glass enclosure which opens both inwards and outwards for complete safety or a curtain and rail arrangement. The latter will help keep the room feeling spacious as the curtain can be pulled back when not in use. And when it comes to choosing a shower, an electric model may be best as it can be run independently of the main bathroom in the household and will provide hot water at any time of the day."