Initial impressions were very promising, easy to arrange the survey where a friendly & knowledgeable sales engineer came to look at the property and put together a proposal. For what it is, it's costly but I thought that it was worth it for peace of mind. Installation arranged easily and work carried out professionally - or so I thought - unfortunately it added more issues. First one is that it’s not been a complete cure, there’s definitely less mould now but it’s now in different places. Secondly, in the winter the house was definitely colder, but I guess you can’t have everything and colder is better than mould. Finally though, and most frustrating, is that I ended up with a major issue with dampness to the joists & contents in the loft, as during wet/damp weather water was being drawn in from various routes (apparently under tiles etc) due to the property having no/minimal natural ventilation into the loft space from outside. I have to say frustrating as this was identified by the EnviroVent sales engineer during the survey, but as I found out later wasn't addressed as part of the work. The lack of response EnviroVent to my numerous calls/email demonstrated that once paid, they were not interested in returning to resolve this. I sought advice (not from EnviroVent) and was advised that as it had been identified as an issue, they should have also fitted Soffit vents. I'm happy to say I've since had this done and seems to have cured the loft problem, however after paying such a large cost to EnviroVent for the main install, this was an issue I shouldn't have had, and additional cost that I shouldn't have had to bear. In summary, It cost a lot and the mould issue we had is much better but not fully fixed. Make sure that you know what they are down to do and make sure it's done. Probably best not to pay the last payment until you're fully happy otherwise you might be in the same position as me and at risk of not getting any snags etc resolved. I guess it's silly really that if EnviroVent had spent 30min fitting the vents initially, or if they’d re-visited to fix this, they’d have got a significantly better review. I'd have given 4/5 if it had all be done as it should (have to knock one off for cost). But with the headache/stress/cost of sorting out remedial work myself, I'm only going for 2/5