Does anyone know of a simple, reliable, easy-to-understand list of
building regs requirements applicable to an old house converted into
two flats? I'm hoping I can avoid reading hundreds of pages of
Building Regulations.

The original conversion was done somewhere around 1991-3, but
I need to bring one of the flats up to scratch in order to sell it
easily. I'm mostly concerned about bringing up to a standard that a
first-time-buyer's lender will deem acceptable. But in case I have to
apply for retrospective building regs approval, I'll need it to meet
the relevant standard for that too.

Thank you,

Hank