Thanks everyone - that's pretty reassuring. A few pieces of information, like this, had frustratingly been withheld until the last minute so we were really wanting to check that they weren't trying to hide unfair costs - which it sounds like they're not. We'd expected to pay maintenance costs but had assumed the ground rent would be lower. Our solicitor is great, but not London based, so wanted to check local info. Some useful advice too - especially about checking upcoming work and taking over the management, cheers. Fingers crossed this will be the last surprise before we exchange...