Want to build a tiny home in your backyard? Here's how you can finance it.

• Backyard tiny homes, called ADUs, are becoming increasingly popular.
• Despite the interest, it can be hard to finance one.
• Here are some ways you can make it happen.

Backyard tiny homes, called accessory dwelling units or ADUs, are becoming more popular as some state and local governments roll back zoning restrictions.

But financing ADUs is still a struggle as mortgage guidelines have not caught up.

That's because government-backed mortgage providers Fannie Mae and Freddie Mac set the strict standard for all other mortgage lenders.

"Until Fannie and Freddie says 'We can take a property with an ADU on it,' then a lot of lenders are going to be scared of doing that, scared of repackaging that loan for Fannie or Freddie in the future," said Ryan O'Connell, founder of How To ADU, an ADU advocacy organization in California.