HOUSTON -

Houston's real estate market is on fire right now. Homes are getting multiple offers within days of going on the market. So, we're revealing the hottest zip codes for home sales.

"It's been very challenging," said realtor Rick Dittemore. "In the 26 years I've been doing this, I've never seen it like this, ever."

Dittemore carries two cell phone these days to keep up with all the business.

He talked with us about Cinco Ranch in zip code 77494. It flanks the Katy-Southeast neighborhood. It's on the Houston Association of Realtors' (HAR) list of the 25 hottest selling zip codes.

"A lot of people want to live here because of the quality of life, the master planned communities, and the schools," said Dittemore. He added, "Plus with the Energy Corridor just down the street we have lots of people relocating either back to Katy or from other parts of the world."

The Energy Corridor zip code -- 77082 -- is another area getting a lot of attention.

Deidra Hubenak is in the market for investment properties. In the past few months the competition to buy a home has increased. "We put several offers out and not only do we not win the bidding but there are multiple offers," said Hubenak. She added, "There are six, eight, ten offers on these houses. It's crazy."

That madness is spreading.

Sugar Land west -- zip code 77479 -- is also on the "hot" list.

In Humble -- 77346 made the cut too.

HAR has an easy equation for coming up with its hotness factor. It's the ratio of pending sales to active listings.

"The average days on market are slipping," said Danny Frank with HAR. "The inventory is going down every month. We in Houston have a desire for new homes. We just don't have enough to sell right now."

As for the hottest zip code right now it's Timbergrove Manor's 77008. Right now there are three times as many homes under contract than there are for sale.

"It's generally if you look at a map, it's in the upper northwestern area around the heights, the 290, 610 area is some of the hottest areas in Houston right now," said Frank.

So what is a buyer to do?

"I would definitely get with an agent that's familiar with the neighborhood and with the area," said Dittemore. He added, "One that's been here a while and has connections with other agents and also has a lot of listings that are coming on the market."

As for anyone thinking of selling, Frank said, "Sell your house today, we need your help."