How to Renovate a Century Home in Ottawa

Renovating a century home in Ottawa presents unique challenges and rewards. Ottawa's heritage includes thousands of homes built between the 1870s and 1930s in Sandy Hill, Centretown, the Glebe, Old Ottawa South, and Westboro. These homes feature craftsmanship modern construction rarely matches, but harbour challenges including knob-and-tube wiring, lead paint, plaster-and-lath walls, rubble stone foundations, and potential heritage designations. A successful century home renovation balances preservation of architectural character with modern comfort, safety, and energy efficiency. This guide p...

Heritage Designations and Regulations

Determine heritage protections before planning any renovation.

Types of Protection

Heritage Conservation Districts protect entire neighbourhoods. Individual designations under the Ontario Heritage Act protect specific properties. The Heritage Register lists properties of interest with less protection. Check City of Ottawa Heritage Services for your property's status. Heritage Perm...

What Rules Cover

Heritage regulations primarily govern exterior alterations visible from public streets: facade materials, windows, doors, rooflines, porches, additions. Interior renovations are generally unrestricted. You can modernize kitchens, bathrooms, electrical, plumbing, and HVAC without heritage constraints...

Common Century Home Challenges

Older Ottawa homes share technical challenges experienced contractors address routinely.

Electrical: Knob-and-Tube

Many century homes retain knob-and-tube wiring, not inherently dangerous when undisturbed but hazardous when covered with insulation or overloaded. Full rewiring costs $15,000-$30,000. Panel upgrades from 60/100 to 200 amp cost $3,000-$5,000. All work requires licensed electricians and ESA inspectio...

Plaster Walls

Plaster-and-lath provides better soundproofing than drywall but requires specialized repair skills. Options: repair plaster ($30-$60/sq ft), install drywall over ($5-$12/sq ft), or replace with drywall ($8-$15/sq ft). Preserving original plaster maintains character and avoids costly removal.

Foundations

Rubble stone, brick, or early concrete foundations may show settling, cracking, or moisture after 100+ years. Assessment ($500-$1,500) should come first. Solutions: repointing ($3,000-$8,000), waterproofing ($5,000-$15,000), underpinning ($20,000-$50,000+), structural reinforcement ($3,000-$12,000).

Modernizing While Preserving Character

The art lies in upgrading systems without destroying what makes these homes special.

Heating and Cooling

Replace outdated heating with high-efficiency furnaces ($3,500-$6,000) or heat pumps ($8,000-$20,000). Ductless mini-splits ($3,000-$8,000/zone) avoid the need for ductwork that would compromise plaster walls. ERVs improve air quality in tight heritage envelopes.

Energy Efficiency

Blown-in cellulose insulation ($3,000-$8,000) installs without removing plaster via small holes between studs. Attic insulation to R-60 ($2,000-$5,000). Window options: restore originals with weatherstripping ($300-$800/window) for heritage compliance, replace with compatible units ($600-$1,500 each...

Century Home Renovation Costs

Expect 20-40% higher costs than equivalent work in modern homes due to older construction complexity.

Budget Ranges

Moderate updates: $75,000-$150,000. Comprehensive renovation: $150,000-$300,000. Major restoration with additions: $300,000-$500,000+. Build 20-25% contingency (vs 10-15% for modern homes). Common surprises: asbestos, additional structural issues, plumbing discoveries.

Finding the Right Contractor

Need contractors with 5-10+ heritage projects in portfolio, understanding of period materials and techniques, relationships with specialty trades (plasterers, heritage window specialists, masonry artisans), and familiarity with Ottawa's heritage permit process. and heritage homeowner references prov...

Kitchen and Bathroom in Century Homes

The most commonly renovated rooms present opportunities to blend period charm with modern function.

Century Kitchen Design

Honour the architectural period: maintain trim profiles, use inset cabinetry, preserve hardwood floors, incorporate period hardware. Open-concept possible but many interior walls are load-bearing — structural engineering assessment ($500-$1,500) required before any wall removal.

Heritage Bathrooms

Complement century architecture with pedestal sinks, clawfoot or freestanding tubs, hex or subway tile, and period fixtures. Plumbing updates ($3,000-$8,000) typically needed. Even modern renovations can connect to heritage character through thoughtful fixture and material choices.

Frequently Asked Questions

How much to renovate a century home in Ottawa?

Moderate: $75,000-$150,000. Comprehensive: $150,000-$300,000. Major restoration: $300,000-$500,000+. Budget 20-25% contingency for hidden issues.

Need a heritage permit?

If in a Heritage Conservation District or individually designated, exterior alterations require heritage permits (4-8 weeks processing). Interior work generally unrestricted.

Should I rewire?

Full rewiring ($15,000-$30,000) recommended during major renovations, especially with knob-and-tube. Improves safety, supports modern loads, satisfies insurance requirements.

Can I insulate without removing plaster?

Yes, blown-in cellulose ($3,000-$8,000) installs through small holes between studs, preserving original plaster.

How to find a heritage contractor?

Look for 5-10+ heritage projects in portfolio, experience with plaster, heritage windows, masonry. Check and century home owner references.

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