Ottawa is full of character homes - the brick century homes of the Glebe, Old Ottawa South and Sandy Hill, the post-war houses of Westboro and Alta Vista, and older stock across the core. They have charm that new builds can't replicate. They also hide surprises behind their walls. If you're renovating an older Ottawa home, here's what's genuinely different and how to plan for it so the surprises don't derail your budget.
Knob-and-tube and outdated wiring
Many pre-1950s Ottawa homes still have some original knob-and-tube wiring, or a patchwork of upgrades done over the decades. It's often ungrounded, can't safely handle modern loads, and insurers increasingly won't cover homes that still have it active.
What it means for your renovation: when walls are open for a kitchen or bathroom project, it's the ideal - and cheapest - time to replace old wiring in that area. Electrical work must be done by an ESA-licensed contractor and inspected. Budget for the possibility of finding more than expected once the walls are open.
Plaster and lath walls
Older Ottawa homes have plaster-and-lath walls rather than drywall. Plaster is heavier, more brittle, and doesn't patch the way drywall does. Cutting into it for new plumbing or wiring takes more care and can cause cracking beyond the work area, and matching profiles and finishes takes skill. A contractor experienced with older homes plans for this rather than being surprised by it.
Old plumbing
Galvanized steel supply lines and cast-iron or undersized drains are common in older Ottawa homes. Galvanized pipe corrodes from the inside and restricts flow; old drains may not meet current code. A bathroom or kitchen renovation is the right moment to replace aging supply and drain lines in the work area - if you don't, you risk redoing finished work later when an old pipe fails.
Un-level floors and out-of-square rooms
A century of settling means floors slope and walls aren't plumb. Cabinets, tile and countertops all have to be installed to accommodate this, which takes more shimming and scribing to look right. It's normal for older homes - it just requires a crew that expects it and prices for it.
Permits and (sometimes) heritage rules
Renovations that move walls or alter plumbing and electrical need City of Ottawa permits, the same as any home. If your property is in a heritage conservation district or is a designated heritage property, exterior changes can face additional review - though most interior kitchen and bathroom work is unaffected. Confirm early whether your home carries any heritage designation, and work with a contractor who pulls the permits and manages inspections for you.
Insulation and comfort
Older Ottawa homes are often under-insulated, and a renovation with open walls is a rare chance to improve it - worth doing given our winters.
Why experience with older homes matters most
The theme running through all of this: older homes reward a contractor who expects the unexpected. The right approach is to plan for hidden conditions up front, document anything found behind the walls with photos, price it as a written change order, and keep moving - so a surprise becomes a decision, not a crisis.
At Ottawa Property Experts, every project runs on a fixed-price written contract. If we open a wall in your century home and find old wiring, rot or undersized plumbing, you get photos and a written change-order price, and you decide - the original price never moves on its own. And every renovation is backed by our 5-year workmanship warranty.
- Do I have to remove knob-and-tube wiring when I renovate an old Ottawa home?
- When walls are already open for a kitchen or bathroom renovation, it's the ideal and cheapest time to replace knob-and-tube wiring in that area. Many insurers won't cover homes with active knob-and-tube, and the work must be done by an ESA-licensed contractor and inspected.
- What surprises are common when renovating a century home in Ottawa?
- Knob-and-tube or patchwork wiring, brittle plaster-and-lath walls, corroded galvanized supply lines, undersized cast-iron drains, and floors and walls thrown out of square by a century of settling. A good contractor plans and prices for these up front.
- Do heritage rules affect my kitchen or bathroom renovation?
- Usually not. Most interior kitchen and bathroom work is unaffected by heritage designation. Heritage conservation districts and designated properties mainly add review for exterior changes - but confirm your home's status early.
Aus Q.
Co-Owner, Ottawa Property Experts
Aus Q. co-founded Ottawa Property Experts with Emad H. He's on every project the company takes on, and writes about kitchens and bathrooms the same way he runs jobs: practical, specific, and with the numbers shown.