I expect to be asking several more questions about this project; but I'm starting with a general one, and will get more refined as things develop.

We are working on finishing our basement, which includes a bathroom. In the original plans, the bathroom was 5' x 8'; which is very tiny. This matches the size and planned layout of a bathroom upstairs, so we've an idea how cramped it will be. We would like to enlarge it a bit, and move some things around to make it more... usable.

The uncertainty I'm running into is dimensions. For example, toilets are typically about 22-24" wide; but most people would be more comfortable with some clearance on either side. I'm uncertain how to estimate the space needed for a toilet. Similarly, counters are usually 24-30" deep; but putting in a sink typically defines a minimum cabinet depth. Finally, while the original plans called for a tub/shower (side entry), we're planning to change that to a corner shower. Tubs seem to be 30" wide; but I expect a corner shower to be wider (perhaps 36" x 36"). And if the shower has a corner entry, should I allow more space to enter/leave the shower?

  • You should really check your local code as it will contain things like minimum clearance from toilet to other fixtures, etc.
    – Steven
    Oct 2, 2012 at 16:25
  • In NYC, 5 x 8 is the standard size bathroom in most apartments.
    – bib
    Oct 2, 2012 at 17:54
  • 5 x 8 is, to my mind, a minimal functional size. I could imagine a bath as small as 5 x 5 with a shower, not a tub. But even at 5 x 8, there's barely any counter space, and minimal storage. We're hoping that, if we push a wall or two out 6" to 1', we can rearrange things and give the room more storage, while possibly feeling less cramped.
    – Scivitri
    Oct 2, 2012 at 18:43
  • Using a pedestal sink or a "eurostyle" vanity (~14" deep cabinet, with the sink basin extending off the top) makes the room more spacious. I had a 5x5 bathroom with just a sink and a toilet and it felt fairly spacious (sorry hard to get a good picture of a small room). Of course you lose some counter space, but you can compensate for that with shelves and/or wall/medicine cabinets.
    – gregmac
    Oct 3, 2012 at 16:41
  • @Scivitri I think 5x5 with a shower is definitely pushing it; you're going to have a hard time getting a layout that works. Unless you either build a wet room, or you don't mind having to sit on the toilet to use the sink, anyway. :)
    – gregmac
    Oct 3, 2012 at 16:44

2 Answers 2


Some of those minimum clearances are defined in building codes and will vary from place to place. In Ohio we use the International Plumbing Code (IPC) and it does define some of these minimums and local municipalities might add additional regulations. But it sounds like you may not be as concerned with the minimum specifications, what you really want to know is what "feels comfortable" and looks/feels good. Unfortunately a question like that is tough to answer.

Luckily people have been dealing with small bathrooms for ages so there are a number of strategies you can employ and there are some specialty fixtures that can help, like narrower bathtubs (28” instead of the standard 30”), shallower vanities/sinks, shallower toilets (10” rough-in instead of the standard 12”), etc.

If you can find a copy of the codes your area uses that can be a good resources if you have the patience to read it. I would recommend an electronic version so you can search for terms.

In the IPC the relevant sections I found are here:

Section 417.4 Shower compartments

All shower compartments shall have a minimum of 900 square inches of interior cross-sectional area. Shower compartments shall not be less than 30 inches in minimum dimension measured from the finished interior dimension of the compartment, exclusive of fixture valves, showerheads, soap dishes, and.safety grab bars or rails.

417.4.2 Access. The shower compartment access and egress opening shall have a minimum clear and unobstructed finished width of 22 inches.

Section 405.3 Setting

405.3.1 Water closets, urinals, lavatories and bidets. A water closet, urinal, lavatory or bidet shall not be set closer than 15 inches from its center to any side wall, partition, vanity or other obstruction, or closer than 30 inches center-to-center between adjacent fixtures. There shall be at least a 21-inch clearance in front of the water closet, urinal, lavatory or bidet to any wall, fixture or door. Water closet compartments shall not be less than 30 inches wide and 60 inches deep.



The standard side clearance for a toilet is 15" as measured from the centre of the floor flange to the side wall and or cabinet. This measurement is increased to 18" for ADA compliance. I wouldn't go much more then that as you will start to feel like the toilet is floating in the room. The standard distance from the back wall to the centre of the floor flange is 12" for a tank type (10" for flush valve type).

Cabinet Depth

I'm not sure what the standard vanity counter depth is but it would be determined by what is available and what size the sink is.

Corner Shower

Showers come in a variety of sizes. While 36" x 36" is common you can also get 34" x 34" and 38" x 38".

You seem to have a good idea on the spaces needed. Your best bet would be to select the fixtures you want to buy (ones that meet you budget and taste). Then confirm that they will fit in the space. If they do not, adjust accordantly (pick different fixtures or increase the bathroom size if an option).

  • Could you please cite sources for these "standards". Not all users are from the same town, city, or even country. Standards vary from place to place, so it's always nice to know what area these standards apply to.
    – Tester101
    Oct 2, 2012 at 16:55
  • @Tester101, the side clearances are as per Canadian building code. The back of wall dimension is an industry (manufacture) standard.
    – pdd
    Oct 2, 2012 at 17:44

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