Why did my contractor's estimate change after starting work?

Contractor estimates commonly change during construction in Ottawa due to unforeseen conditions discovered once work begins, but legitimate changes should be documented and approved before proceeding.

When contractors open up walls, floors, or structural elements, they often discover issues that weren't visible during the initial assessment. In Ottawa's older neighborhoods like the Glebe, Westboro, or Sandy Hill, homes built in the early-to-mid 1900s frequently reveal outdated electrical systems that don't meet current Ontario Electrical Safety Code requirements, plumbing that needs updating to meet Ontario Building Code standards, or structural issues like inadequate support beams.

However, there's a crucial difference between legitimate change orders and contractor manipulation. A reputable contractor should immediately stop work when they discover an issue, document it with photos, explain why the change is necessary (often referencing specific Ontario Building Code sections), provide a written change order with costs, and wait for your written approval before proceeding.

Red flags that suggest problematic practices include:

• Starting additional work without your approval


• Verbal-only change orders with no documentation


• Discovering "problems" that seem convenient for the contractor


• Dramatic cost increases (50%+ over original estimate)


• Pressure to approve changes immediately


• Claims that work "must be done today" for safety when it's not an emergency

Protecting yourself in Ottawa involves several steps:
Contact City of Ottawa Building Code Services at 613-580-2424 if you're unsure whether discovered issues actually require remediation under current codes. For electrical issues, verify requirements through ESA (Electrical Safety Authority) at esasafe.com, and for gas or HVAC issues, check with TSSA at tssa.org.

Always demand written change orders that specify exactly what additional work will be performed, why it's necessary (including code references), the additional cost, and timeline impact. Take your own photos of the discovered conditions. If the contractor claims electrical or structural work is required for safety, get a second opinion from a licensed professional.

Your rights under Ontario's Consumer Protection Act include:
The right to receive written estimates and change orders, reasonable time to consider changes over $50, and protection against unfair business practices. If a contractor begins work without approval or misrepresents the scope of necessary work, contact Consumer Protection Ontario at ontario.ca/consumer.

For significant disputes, consider involving the Tarion Warranty Corporation if it's new home construction, or consult with a construction lawyer familiar with Ontario's Construction Act (formerly Construction Lien Act). Remember that you have the right to hold back 10% of payments for 60 days after substantial completion under Ontario law.

The key is establishing clear communication protocols upfront and ensuring your contractor follows proper procedures when changes arise. Legitimate contractors welcome transparency and documentation - those who resist these practices should raise immediate concerns.