City officials say contractors were "underpinning the basement" when neighbours reported hearing a loud crack. Firefighters showed up shortly afterward.
The shift in the structure was so severe that the homeowners were not allowed to enter the house to retrieve their belongings because officials said it was too dangerous.
Planning a renovation?
The Canadian Home Builders' Association, whose website proclaims to be "the voice of Canada's residential construction industry," representing some 8,000 firms across the country, provides resources and tips for homeowners looking to renovate.
CBC News spoke with Joe Vaccaro, the head of the Ontario branch of the CHBA, and he laid out the top four steps his organization says homeowners should take before starting any big renovation. The Insurance Bureau of Canada adds a fifth: contact your insurance provider, particularly if you are going DIY.
The five steps:
Hire a professional. Contractors in Alberta, B.C., Manitoba, New Brunswick, Ontario and Saskatchewan who meet the criteria laid out by the CHBA can carry a Renomark certification.
To be certified members are held to a code of ethics, which includes requiring "contractors to carry a two-year warranty and $2-million liability insurance," says Vaccaro.
The CHBA offers a Reno Guide as well as a list of certified contractors on its website.
Get a contract. "Get it in writing," says Vaccaro. "Consumers should always be looking for a contract. That's your first line of protection" when hiring contractors.
The contract should include the scope of work to be done, price, schedule of payment and a timeline for completing everything.
Vaccaro also says its important to note that homeowners are liable when it comes to subcontractors hired by a principal contractor.
The Construction Lien Act in Ontario, along with similar hold-back requirements available in other provinces, allows homeowners to withhold 10 per cent of the total cost of a contract for up to 45 days following its completion.
The purpose is to provide homeowners a means to ensure a contractor finishes all the outstanding parts of the agreement.
Communicate with your contractor and discuss concerns. A change order, basically a written amendment to the contract specifying any additional work that may have come up during the course of a job, is another step the CHBA recommends.
Get permits. Ensuring that a contractor has all the necessary civic permits is one more step that Vaccaro says is necessary when undertaking a home renovation.
Obtaining a permit from the city not only makes your work legal, but "pays for a third party, usually a city inspector, to come make sure the work is being done to code and safely."
Contact your insurance company. The Insurance Bureau of Canada, which represents private home, car and business insurance sellers, also recommends hiring a licensed contractor for structural renovations.
"A homeowner needs to ask for some sort of evidence of liability coverage," says Steve Kee, a spokesperson for the IBC.
As well, for those looking to do the project themselves, Kee stresses that it's important to contact your insurance provider in advance.
"If you do work on your own and don't tell your insurance provider, coverage may be impacted." A builder's risk policy can be added to a homeowner's insurance policy, usually as a one-time fee, says Kee.
"When in doubt, ask your insurance provider."
The IBC also recommends re-evaluating home insurance coverage every year or two, regardless of structural improvements, to ensure one's policy is up to date with market prices.
"Check the value of your home against your coverage," says Kee. "It's just sound practice. In today's world, you want to be covered."Suggest a correction