Score Requirements in a Nutshell. If you want to use a conventional mortgage loan to buy a house, you will probably need a credit score of 620 or higher. In 2015, we've been seeing some lenders set the bar even higher, at 640.When using a government-backed loan (such as an FHA or VA loan), you might get approved with a score below that range.f you asked me what credit score you needed to buy a house back in 2005, I'd say it didn't really matter. Back then, you didn't need much more than a job and a Social Security Number to get a loan. Those were the days of housing bubbles and easy credit..