Hi, As your post title suggests, you need urgent legal advice rather than anything else, from a solicitor experienced in construction disputes. I work in this area (although on high-value disputes rather than domestic ones), and can recommend this person https://www.greenwoods.co.uk/our-people/lorna-carter/ for domestic disputes. If you call she should be able to give you some immediate, and free, initial advice. Going forward, you'll have to pay for her advice, but it will be money well spent in the long run I imagine. Good luck.