You can't just make a copy, see for car detail you might have created a database which includes fields like carname, car make, model, price, etc etc, and teh design also you might have given ID's to controls like txtCarName etc
You can make little modifications and use it, its better to maintain a new database for house clean with new tables,
Even the Business Logic would be different for both the projects
You have to make slight changes like creating new database, designing forms, changing store procedures, functional logic etc..