In reply to Mr Pinchy:
Yes, and it's the best thing ever. Our water is very hard and without the softener the bath water is scum city. With it, it's silk heaven. We use less soap products too.
Ours is in the garage, but they fit under the sink fine. Its our second one. My Father installed the first one when he built our house in 1989. Can't remember the make of that. But our current model is a Harvey Mini max. It softens the whole cold water system apart from the Kitchen and Bathroom sinks.
http://www.softaquasystems.co.uk/
We used this guy, he's a bit full on, but pretty good.
One thing to consider. We were about to re-new our boiler last year (Got it fixed in the end) But when British Gas gave us the quote they did say that we would need a certain type of boiler because of the softener. Not sure why, he did say, but didn't take much notice of him TBH.
HTH. We wouldn't be without ours.