I want to buy a tortoise. i live in the u.k. need some info please x?

i would like to buy a tortoise to keep as a pet. i have looked on the internet and looked at what seem like good sites, lots of info about what they eat etc. marginated tortoises seem to be the type i would go for. there just doesnt seem much about whether you need an outside hutch for them aswell as an inside one? can you let them wander around your house or garden for excersise (obviously supervised)? thankyou x