The US will often have guarantees on a construction loan, and sometimes the bank will even inspect the property as it is being built and only release funds when certain points are hit - 30% to start, 20% when foundation is poured, 20% on framing, 30% on completion. And then the loan will be refinanced to a traditional mortgage (construction loans are usually short-term and higher rate).

Many builders will therefor "self-finance" and sell the customer a "built home" direct into a normal mortgage.