Bridging Loans are no different to long-term mortgages in that they are secured by a first charge or the second charge against your property. Because they are secured, the same steps of valuation and preparation of a legal charge deed have to be taken as with a normal term mortgage.
However, bridging loans are designed to be arranged quickly, and to run for a 1-36 month duration. Interest is taken from the loan balance at the start of the term, with the option to pay back the balance at any time, usually with no exit penalties. As loan durations increase past 18 months most lenders look for the loan to be serviced with monthly interest payments. Because interest payments are already taken from the loan balance, there are usually no affordability checks.