In today's market people sometimes wondered if renting might be an alternative to selling their existing house, especially when there is any kind of relocation need, like having found a new job in a far away city. 

Before you start looking for a tenant for your existing house or looking for for a new home to buy at the new location however, you need to check first with your mortgage company to make sure that will work. 

With a mortgage already in place for your existing house, your income to debt ratio may be way off, not qualifying you for an additional new mortgage. 

So check with your mortgage company first and if that is not satifying, ask different mortgage companies. Requirements may differ from company to company.