Homeowners at a new development in Stittsville are patrolling their neighbourhood after two new homes in the development went up in flames in three days.

So far, investigators have determined that the first fire, which was reported on Friday night, was deliberately set. The cause of the second blaze is unknown. However, arson investigators have ruled that fire suspicious.

Tim Larocque owns the house that went up in flames on Monday night. He was supposed to move in with his wife and two kids in just two weeks.

He says his new home was vandalized a few weeks ago: the windows were smashed and smeared with tar.

"About a month ago, I saw three teenagers walk into my house and called it into the police," Larocque said.

Now, the house is a complete write-off and his family is trying to figure out exactly what they're going to do.

Firefighters say damage in the basement was so extensive that crews were forced to evacuate because of the risk that the floor could collapse. Once outside, firefighters carried out a defensive attack on the blaze.

Three days earlier, a fire at a model home on Loreka Court caused $250,000 in damage. A family of four was scheduled to move into that home in a couple of weeks.

So far, police say their investigation doesn't link the two fires, but investigators are looking into that possibility.

The development, which houses 22 homes, is owned by Tartan and Tamarack. The fires, though, have new homeowners worried about their safety and security.

"I'm very concerned about the home and I'm concerned once we're in the home, there's nobody there, so once we're asleep, what's going to happen?" asked homeowner Dan Gariepy.

The homeowners have now taken it upon themselves to patrol the area in the evenings. As a precaution, Tartan and Tamarack have hired a private security firm to guard the area.

The firm will patrol the development from 7 p.m. to 4 a.m. every night -- beginning Tuesday.

With a report from CTV Ottawa's Joanne Schnurr