1. Nationalise building inspections. A cause of Grenfell and others is that the inspectors being private companies are unlikely to fail a company because then they would not get any more work from that company. It is the same as the failure of audit companies which gave us Enron.
2, Crack down on developers evading the requirement to build social housing and increase the percentage of social housing they have to build before they can build for profit.
3. Make council compulsory purchase of land easier and quicker so that developers can't just sit on the land. Land that receives permission to build must be built upon within a set (but reasonable) timeframe, say 2 years, after which it should be compulsorily sold to the council at approx 80% of its value at the time permission to build was given.
4. Only residents or companies who pay tax in the UK should be allowed to buy property here. Any properties already owned by non-residents or companies must be sold within an announced timeframe, say 5 years.
5. Build lots of council houses/flats obviously, and to high environmental standards.
6. Any domestic residence that has been left empty for more than 2 years can be purchased by the council for a trivial sum (say equivalent to the cost of the land registry fees)
7. Land Registry data should be available free on-line. We need to know who owns what.