How do you describe a person who can afford a house. Can he be called 'affordable' person?

A person who can afford to buy a house would be referred to as a person who considers the house 'affordable', meaning he has sufficient money to buy the house.

If the house is particularly expensive, he might be referred to as an 'affluent' person, meaning a person who could be considered wealthy.

If the home-buyer needs and is able to borrow finance to buy the house, he'd be described as a 'good financial risk' who will find the repayments affordable.