This article shows how UK Bathroom Guru added a downstairs toilet under the stairs of a semi detached house in Leeds. It also shows the steps required to make it a success, along with information regarding the general installation process and how long the work took to do.

Adding A Downstairs Toilet With Bathroom Installation In Leeds


The existing plumbing & the space available will be the main factors in determining whether you can put a downstairs toilet under the stairs (as in this example).

  • Floors will normally have to be lifted to run hot & cold supply pipework to the toilet & basin but in this example they were dropped down from the 1st floor landing as there was a concrete floor downstairs.
  • Running pipework for any new radiators will almost always involve lifting floorboards in the adjoining room to extend the pipework that currently feeds the nearest radiator. We chose not to install one in this example.
  • Waste water from the toilet & basin needs to run downhill (in a fairly straight line) to the nearest soil stack, which is normally on the outside of your house.

The position of the intended downstairs cloakroom relative to the existing soil pipe is critical. i.e. if the space you want to turn into a downstairs toilet is on the other side of the house to the soil pipe, you may have difficulties in installing everything you want.


Minimum Size For A Downstairs Toilet With Bathroom Installation In Leeds

You can only add a downstairs toilet if you have space.

The minimum size required for a downstairs toilet is probably around 80cm x 140cm, which is what this example is, but could be as little as 70cm x 130cm in some circumstances (assuming only a toilet & hand basin are required).

PS Don’t forget the space taken when the door swings open as well! An outward opening door is best to remedy this potential problem.


Frosted Glass With Bathroom Installation In Leeds, Image Courtesy of

Existing windows (that may be clear) will need to be made obscured for privacy purposes.

To make an existing (clear) window obscured (and to save the expense of a new window) I recommend using this.

An alternative to this is to fit a blind.

If you do not have a window in the intended position of your new downstairs toilet then you can either add one or settle for artificial light. This will depend on your preferences, budget and timescales, with the cheaper option being to not add a new window and the expense associated with it – probably £450+ all told.

You should not normally require planning permission to do this, but will need to comply with building regulations – speak to your local building control officer for clarification.

Case study

This job involved adding a downstairs cloakroom, consisting of a toilet & basin into an area under the stairs in this fairly typical 3 bed semi.

The space under the stairs was divided up into 2 different spaces – the toilet & a separate storage space.

This storage space was accessed by a new door that was knocked through the lounge wall.

Positioning this separating wall was crucial – too far to the right in the drawing below and the new doorway into the lounge would not fit and the headroom above the toilet would decrease, but too far left and the space between the toilet & the basin would be too small.

Planning A Downstairs Toilet Under The Stairs With Bathroom Installation In Leeds

Work done

Adding A Doorway Under The Stairs With Bathroom Installation In Leeds

Fitting A 1930's Door With Bathroom Installation In Leeds

A hole was knocked through under the stairs and a lintel, doorframe and door was added before the plaster was made good.

Alternative To Stud Wall With Bathroom Installation In Leeds

The 2 spaces (toilet & storage area) were divided with custom made plywood shelving (clad in plasterboard & skimmed on the toilet side) rather than a traditional stud wall.

This would utilise the existing space better and allow for plumbing pipework to be concealed but accessible.

Removing Blown Plaster With Bathroom Installation In Leeds

Blown plaster was removed from the brickwork in the toilet.

1st Fix Pipework With Bathroom Installation In Leeds

Pipework was run in the walls and in the new ‘stud’ wall for the toilet & basin (above).

Adding A Downstairs Toilet Soil Pipe Work With Bathroom Installation In Leeds

The plumbing on the outside of the house was amended to take waste water away from the new toilet & basin (as can be seen to the right of the main vertical stack in the picture.)

Plasterboarded Downstairs Toilet With Bathroom Installation In Leeds

Painted Walls In Downstairs Toilet With Bathroom Installation In Leeds

The walls were then reboarded, plastered and painted.

Painted Shelving Under Stairs With Bathroom Installation In Leeds

The shelving, achitraves and doorframe etc were also painted at this time.

Custom Made Cabinets With Bathroom Installation In Leeds

Storage space in the cloakroom was added in the form of custom made cabinets that were hung above the window.

Lighting In Downstairs Toilet With Bathroom Installation In Leeds

The ceiling light was relocated from the ceiling to the wall opposite the new cabinets, ensuring they could be opened without clashing into it (as was the burglar alarm).

Porcelain tiles were used to tile the wall behind the toilet & also the basin splashback (as well as the window cill) in order to tie the design together.

These were then finished with colour co-ordinated grout and chrome trims.

Engineered wooden flooring was laid, and skirting boards were fitted around the perimeter of the room over the top of this flooring for a neat finish without the need for additional beading.

Downstairs Toilet With Bathroom Installation In Leeds

A short projection toilet was fitted to minimise the distance it projected out into the (small) room.

An alternative to this would have been to fit a back to wall toilet pan that had the cistern on the other side of the new stud wall, which would have saved the depth of the cistern – about 15cm. See this case study for an example.

Wall Hung Basin And Semi Pedestal In Downstairs Toilet With Bathroom Installation In Leeds

A wall hung (as opposed to floor mounted) basin was used to give a feeling of space by maximising the floor space visible underneath. All pipework was concealed in the wall behind, and was carefully planned at the outset to ensure strong fixings.

Adding A Downstairs Toilet With Bathroom Installation In Leeds

Accessories were added such as a towel holder & toilet roll holder.

A large mirror was added to increase the sense of light & space.

Process & Timings

This work took under 1.5 weeks from start to finish and involved the application of many trades that the customer may have found difficult to source & co-ordinate independently:

  • Joiner
  • Plumber
  • Tiler
  • Floor fitter
  • Plasterer
  • Labourers & decorators
Anything else?

If you have any questions about this article or any others, please feel free to contact me or fill in the call back form on this page.