In halls most of the bathrooms are shared.
See this thread for information about finding a flat to live in:
"Accommodation in St.Andrews seems to be harder to find each year, Many students are awaiting their exam results or trying for a place via clearing, it was the intention that all first year students go in the halls but this is not the case. Many would rather live in a flat or house. So that leaves lots of students looking for the few flats that are available.
Where can you find flats, First off try here there may be students graduating who have a space in a flat so advertise on here. but ensure that you let them know that you are flexible in your demands, for example that you don't mind if you share or not or if you smoke or not, or if you are likely to party too much. Try to make it as easy as possible for them to fit you in somewhere.
Next try the letting agents.
The websites of letting agencies are:
www.evebrown.co.uk
www.rollos.co.uk
www.md-c.co.uk
another source is the local classified section of the local paper.
the St Andrews Citizen or for a little further afield try the Courier & Advertiser.
Other people will be in the same position as you so you might be able to find flatmates on message boards like this one -
a few websites that have message boards similar to this one are
www.saint-andrews.co.uk
www.cityofstandrews.co.uk
the website owners are quite approachable for advice as their sites don't charge for advertising or posting requests etc. So it seems they are not there to make money,
the first link is run by Ken who lives in the USA but visits St.Andrews regulary and the other is run by Kevin who lives in the town.
I wish i could offer more help in your time of need, but there are places available
good luck "
hope this helps un peu