The amount the bank is willing to loan on a residential property depends on many different aspects such as the credit score of the buyer, value of the property and the loan program available to the buyer. Where the condition of the property comes into play is when considering the value. The bank will require an independent appraisal of the property in which the appraiser will view the property and compare it to other comparable properties recently sold. They will also note any issues that may be required by the loan program (FHA and VA financing have specific requirements for the property).
This is a great question and unfortunately does not have a specific answer. In today's lending industry, there are many variables that effect a homes marketability. If you have a specific property in mind, I would be more then happy to look it over, answer any questions you may have and give you my best recommendation as how to proceed.
I hope my answer gives you a little more clarity to your question and wish you the best of luck with your purchase or sale.