One of the most regrettable do-it-yourself renovation projects Bryan Baeumler has ever seen was a three-storey townhome with all of its load-bearing walls knocked out.

“It was pretty close to collapse,” said the host of HGTV’s Disaster DIY.

The woman who owned the early 1900s-built home had no idea what she was doing, he said.

So how can homeowners avoid disaster DIYs?

Common sense, says Baeumler who owns Baeumler Quality Construction in addition to hosting the popular reno show.

“Common sense is worth its weight in gold,” he added. “It’s a dying art.”

And avoiding these common mistakes: Underestimating cost; overestimating your own skill level; and underestimating how long the project will take.

Before doing anything, Baeumler said, sit down and come up with a realistic budget, adding a 15 to 20 per cent contingency fund to keep in your back pocket in case of emergencies.

Do-it-yourselfers should also nail down a realistic schedule, taking into account children, jobs, friends, family and things like Christmas, Mother’s Day, and so on.

And finally, don’t get in over your head, he said.

“The three jobs I always tell people to hire someone in for are electrical, plumbing, and structural work,” he said.

Jobs people can do themselves fairly easily include painting and things like putting in a new tile backsplash in the kitchen.

The key is to start slowly, he said.

“I’ve seen guys try and build additions and they can’t put a nail in with a hammer,” he said.

As for where to learn how to do a job right, Baeumler said there are plenty of books and website forums out there on how to renovate.

His own company’s website, Baeumler.ca, has a forum for giving and getting tips, but be wary of the information that’s offered on any site, he said. “There are a lot of ‘anonymous experts’ that aren’t necessarily experts,” he said.

In addition, big box stores have how-to seminars on different projects throughout the year, he said.

Last but not least, Baeumler said, know when to throw in the towel and call a professional.

If you’re mentally anguished at the thought of continuing the project; if you’re dreading continuing with it; if you’re way over budget; if you have no idea which way to go; or if you’re feeling overwhelmed, it’s time to quit.

“If you’re at that point, it’s time to end the suffering and just call someone in,” he said.

Want to see more of Bryan Baeumler?

• Disaster DIY airs on HGTV, Thursdays at 9 p.m. EST.

• Baeumler is currently taping his new show, House of Bryan, which gives viewers a behind-the-scenes look at his own home renos while he juggles life with his wife, two children and managing his construction company.