Properties liable for unknown future costs
Leasehold properties, in particular, often include obligations to contribute to repair and maintenance of common parts, and such costs are not always predictable or guaranteed. If future costs are substantial, they could create financial difficulty and might also make the property less attractive to sell. So a lender will need as much information as possible about future cost liabilities when making a lending decision.
More information about new build leasehold properties can be found here.
Other obscure costs - such as chancel repair - might be identified as a risk for certain properties as part of the conveyancing searches. Lenders will usually require the borrower to take out an indemnity (insurance) against the risk of being liable for such costs, if a risk is identified.