Key Dimensions to Know for the Perfect Bathroom Layout
Bookmark this valuable guide to choosing the right-sized sanitaryware for your washspace
Eva Byrne
24 July 2023
I'm an Architect + House Consultant based in Dublin. I specialise in House Consultations to maximise Space, Light and Storage in your home. Whether you are planning a Renovation, Extension or New Build project, I aim to help you get your project off to the best possible start and to make best use of your cents and centimetres.
I'm an Architect + House Consultant based in Dublin. I specialise in House Consultations... More
Scene of our daily ablutions, the bathroom is a space where we crave calm and a sense of ritual. But creating this oasis can be challenging, especially in a small room. The secret is to choose fittings of an appropriate size and to locate each of these to best advantage.
As part of our Bathroom Planning guide, here’s an explanation of the dimensions and space needs relevant to each element, from basins to baths and showers.
Starting your bathroom project? Read How to Plan for a Bathroom Renovation
As part of our Bathroom Planning guide, here’s an explanation of the dimensions and space needs relevant to each element, from basins to baths and showers.
Starting your bathroom project? Read How to Plan for a Bathroom Renovation
1. Single basin
You’ll find an endless array of basin sizes and configurations, but a 50cm-60cm wide x 40cm deep design will suit most family bathrooms perfectly. A basin as small as 45cm wide will work well for an en suite or smaller bathroom.
Where space is limited, you can fit the basin snug to a wall on one side, but you’ll need to allow 20cm between the basin and any other fitting.
A key consideration is to choose a tap with a spout appropriate to the design of the basin. For instance, a short spout on a flat-bottomed, large basin, as opposed to one with a slanted base, may lead to the basin-bed not being cleared properly after each use. This can lead to a build-up of scum and grime.
Choosing a tap with a longer spout that will be closer to the basin bottom can solve this, as the water will be able to clear the waste better.
More: How To Choose The Right Taps for Your Basin
You’ll find an endless array of basin sizes and configurations, but a 50cm-60cm wide x 40cm deep design will suit most family bathrooms perfectly. A basin as small as 45cm wide will work well for an en suite or smaller bathroom.
Where space is limited, you can fit the basin snug to a wall on one side, but you’ll need to allow 20cm between the basin and any other fitting.
A key consideration is to choose a tap with a spout appropriate to the design of the basin. For instance, a short spout on a flat-bottomed, large basin, as opposed to one with a slanted base, may lead to the basin-bed not being cleared properly after each use. This can lead to a build-up of scum and grime.
Choosing a tap with a longer spout that will be closer to the basin bottom can solve this, as the water will be able to clear the waste better.
More: How To Choose The Right Taps for Your Basin
2. Double basin or vanity unit
If space allows, a double basin or double basin vanity unit is a great addition to a busy bathroom. Depending on the design, you’ll need to allow 150cm-180cm for two basins side by side.
Whichever basin you choose, you should allow at least 60cm between the front and the wall or any other fitting opposite for passage.
If space allows, a double basin or double basin vanity unit is a great addition to a busy bathroom. Depending on the design, you’ll need to allow 150cm-180cm for two basins side by side.
Whichever basin you choose, you should allow at least 60cm between the front and the wall or any other fitting opposite for passage.
3. Wall-mounted toilet
A toilet hung from the wall, and with a concealed cistern, brings a sense of space to any bathroom. Cleaning the floor is so much easier, too.
You can vary the height of the pan to suit your personal taste, with around 50cm above the floor a good average. Leave at least 15cm between the bottom of the pan and the floor for easy mopping. The toilet pan will typically average about 52cm in depth, in front of which you will need to leave at least 60cm clear for passage.
Concealed cisterns typically measure 15cm-25cm in depth, allowing for a handy shelf or even storage cupboards on top.
Find a local bathroom designer and read reviews from previous clients.
A toilet hung from the wall, and with a concealed cistern, brings a sense of space to any bathroom. Cleaning the floor is so much easier, too.
You can vary the height of the pan to suit your personal taste, with around 50cm above the floor a good average. Leave at least 15cm between the bottom of the pan and the floor for easy mopping. The toilet pan will typically average about 52cm in depth, in front of which you will need to leave at least 60cm clear for passage.
Concealed cisterns typically measure 15cm-25cm in depth, allowing for a handy shelf or even storage cupboards on top.
Find a local bathroom designer and read reviews from previous clients.
4. Floor-mounted toilet
Traditional toilets continue to improve in terms of design, with a large range of styles and sizes available.
Compact versions as small as 36cm wide x 62cm deep are now available – great where space is at a premium. You’ll need to allow at least 20cm each side of the toilet for ease of fitting and access.
Some floor-mounted toilets come with concealed cisterns, as seen here. Contemporary concealed cisterns are accessed via the flush plate, eliminating the need to provide removable shelves or to dismantle the housing if ever there’s a problem with the cistern.
Traditional toilets continue to improve in terms of design, with a large range of styles and sizes available.
Compact versions as small as 36cm wide x 62cm deep are now available – great where space is at a premium. You’ll need to allow at least 20cm each side of the toilet for ease of fitting and access.
Some floor-mounted toilets come with concealed cisterns, as seen here. Contemporary concealed cisterns are accessed via the flush plate, eliminating the need to provide removable shelves or to dismantle the housing if ever there’s a problem with the cistern.
5. Bath
The average bath measures 170cm long x 70cm wide, but you’ll find there are designs to suit most bathroom shapes and sizes.
A bath 130cm long x 70cm wide is no larger than a generous shower tray, but will allow the most die-hard bath fan a good soak in a compact bathroom.
Make sure you climb in and test how a bath suits you before you commit to purchase. Too deep or too short a tub can be annoying and completely spoil the bathing experience. A doubled-ended bath with the tap in the middle, as seen here, can be great for bathing small children – or for sharing!
The average bath measures 170cm long x 70cm wide, but you’ll find there are designs to suit most bathroom shapes and sizes.
A bath 130cm long x 70cm wide is no larger than a generous shower tray, but will allow the most die-hard bath fan a good soak in a compact bathroom.
Make sure you climb in and test how a bath suits you before you commit to purchase. Too deep or too short a tub can be annoying and completely spoil the bathing experience. A doubled-ended bath with the tap in the middle, as seen here, can be great for bathing small children – or for sharing!
6. Shower tray
The bigger the better nowadays when it comes to shower trays, but the reality is that anything smaller than 80cm x 80cm will feel very cramped.
A quadrant tray, where one corner is rounded, can reduce the impact of the shower enclosure in a small room without compromising on the comfort in use.
A rectangular shower tray will provide the optimal showering experience and, depending on the location of the shower head, may even eliminate the need for a shower door. A tray at least 150cm long will be needed to achieve this. A fixed glass panel along the length of the tray, with at least a 60cm gap for access to the shower, can protect the room from splashes.
More: How to Choose a Shower Tray
The bigger the better nowadays when it comes to shower trays, but the reality is that anything smaller than 80cm x 80cm will feel very cramped.
A quadrant tray, where one corner is rounded, can reduce the impact of the shower enclosure in a small room without compromising on the comfort in use.
A rectangular shower tray will provide the optimal showering experience and, depending on the location of the shower head, may even eliminate the need for a shower door. A tray at least 150cm long will be needed to achieve this. A fixed glass panel along the length of the tray, with at least a 60cm gap for access to the shower, can protect the room from splashes.
More: How to Choose a Shower Tray
7. Wetroom
Advances in wetroom technology have liberated us from the need for shower trays in many situations, with level-access shower solutions more and more achievable.
You’ll need to allow for a space at least 80cm wide for showering, with any enclosure optimally 190cm high.
Unless you have a very large space with the shower in a distinct zone, it’s generally preferable to allow for glass, as here, or other panels to contain the shower water.
More: 7 Common Wetroom Mistakes and How to Avoid Them
Advances in wetroom technology have liberated us from the need for shower trays in many situations, with level-access shower solutions more and more achievable.
You’ll need to allow for a space at least 80cm wide for showering, with any enclosure optimally 190cm high.
Unless you have a very large space with the shower in a distinct zone, it’s generally preferable to allow for glass, as here, or other panels to contain the shower water.
More: 7 Common Wetroom Mistakes and How to Avoid Them
8. Storage
As with any room, plan your storage as part of your space layout from the start. Wall cabinets or vanity units with shallow shelves are always useful in a bathroom: shelves 12cm deep will accommodate toilet rolls as well as most other bathroom supplies.
A shelf depth of 45cm is ideal for storing towels and other items of bathroom linen. Shelves shallower than this will work, too – you’ll just need to fold your towels accordingly.
Adjustable shelves will be handy for housing a variety of contents, from short medicine bottles to super-tall cleaning bottles. Under-basin drawers provide handy storage, too. With the flotsam and jetsam stored beautifully out of sight, your only task now is to set about enjoying your very own oasis of calm.
Tell us…
What is your number one want when it comes to bathroom design perfection? Share your thoughts in the Comments.
As with any room, plan your storage as part of your space layout from the start. Wall cabinets or vanity units with shallow shelves are always useful in a bathroom: shelves 12cm deep will accommodate toilet rolls as well as most other bathroom supplies.
A shelf depth of 45cm is ideal for storing towels and other items of bathroom linen. Shelves shallower than this will work, too – you’ll just need to fold your towels accordingly.
Adjustable shelves will be handy for housing a variety of contents, from short medicine bottles to super-tall cleaning bottles. Under-basin drawers provide handy storage, too. With the flotsam and jetsam stored beautifully out of sight, your only task now is to set about enjoying your very own oasis of calm.
Tell us…
What is your number one want when it comes to bathroom design perfection? Share your thoughts in the Comments.
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Hello Isla! Comforting to see a familiar name! Gosh, I didn’t know you were a structural designer. How lucky you were able to help out the plumber!
@chemistrykaren I am also the person who teamed a waterfall tap with a large arcing fall of water together with a small cloakroom basin so that everyone who subsequently washed their hands got soaked. The tap when fully open deposited the water neatly past the basin. My previous plumber kept quiet about the obvious design flaw of course.
Sink….basin…Potato, potahto