Hi
Where to practise from, has to be one of the most important decisions any new therapist, or for any therapist that moves geographical location.
I concur that it comes down to the resources (money, space, etc) that you have available and how you use these.
If you don't have the luxury of a spare room then making another room, like the living room, double up as your treatment room may be the only option particularly if you are unable to rent a room.
I have found that as long as everything is tidy, uncluttered, and most importantly, that you are comfortable in your own space, then using your home can be successful.
Be aware of the disability access issues though for those of you who have rooms upstairs. To ease your mind (if you haven't thought of this) offer a mobile service for anyone who has a disabilty that prevents them climbing stairs or have a "one off" or have an occasional arrangement with another local therapist (hire their room for an hour) who has disability access.
Lastly, if you don't want to work from home and hiring a room every week is too much of an expense (or worry) and you don't fancy the idea of being a mobile therapist here is another option. Contact other local therapists who you know have hired their own room and ask if you can have an arrangement to hire it for a few hours when you need to. This can be a way of getting your practice going without having to commit to hiring a roompermanently which may remain empty because you haven't built up your client base yet.
Best wishes