Homes in BS31 sell for a median of £410,000 across 476 sales over two years (HM Land Registry), which is +4% against the Bath and North East Somerset median of £395,750. Set against the local average rent of £1,881 a month (ONS), that implies a 5.5% gross yield here versus 5.7% for Bath and North East Somerset as a whole.
Rents are published per district, not per postcode, so the yield above applies the Bath and North East Somerset average rent to BS31 prices. It's the right way to compare postcodes on entry price, but rents do vary street by street, and gross yield ignores costs, voids and mortgage interest.
BS31 averages tell you where to look, not whether one particular flat stacks up. Paste a listing and gemhome runs the actual numbers: yield, cash flow, the lender stress test, EPC work and what the public records say about that specific address.
Check a buy-to-let