Kopman Build builds home additions on the 1950s and 1960s homes that define Humber Valley — postwar bungalows and split-levels on deep ravine lots and golf course edges where thoughtful additions deliver exceptional returns. We have managed the full scope from permit to occupancy on some of Etobicoke's most complex sites since 1999.
Humber Valley's postwar housing stock offers genuine opportunity: well-built mid-century homes on generous lots in one of Etobicoke's most desirable enclaves. A well-executed addition here — rear, second-storey, or a combination — can double livable space without surrendering the neighbourhood or the land value that comes with ravine and golf course proximity.
These projects require more than standard construction competence. Ravine-adjacent lots trigger Toronto and Region Conservation Authority (TRCA) review alongside the City of Toronto building permit process. The heritage character of the streetscape means the architectural integration has to be deliberate. And the premium market expects premium execution throughout — materials, trades, and project management included.
Dustin Kopman founded the company in 1999 after growing up working in construction through his family's firm, G&G Enterprise. That background means every Humber Valley project is managed by someone who understands the structural, regulatory, and craft demands of adding onto an existing mid-century home — not just the sales pitch.
Single-storey and multi-storey rear additions extending into Humber Valley's characteristically deep lots, with full structural integration and ravine setback compliance.
Full second-storey additions on Humber Valley bungalows — doubling living space while respecting the established street character and mid-century architecture.
Full-scope additions that expand both floors simultaneously — the most efficient way to maximize space on a single permit and construction cycle.
Garden suites on eligible Humber Valley rear yards under Toronto's expanded as-of-right zoning — subject to ravine and TRCA conditions on applicable lots.
Converting attached or detached garages into living space, home office, or income-generating units — common on Humber Valley's wider lots.
Smaller additions — mudrooms, sunrooms, bump-outs — designed to integrate cleanly with existing mid-century architecture and finish standards.
We visit your Humber Valley property, assess ravine and TRCA conditions, and document the project in writing — scope, budget, and timeline.
A detailed line-item estimate with allowances and contingencies, so you know the number before committing.
We manage all permit applications, TRCA review where required, engineering consultants, and approvals — nothing falls through the cracks.
Full-time site supervision, weekly updates, and open-book cost tracking throughout the project.
Structured handover with all documentation, warranties, and a 12-month attendance window post-completion.
Rear additions and second-storey additions are the most common in Humber Valley. The postwar bungalows and split-levels throughout the neighbourhood lend themselves well to full second-storey additions that double living space while preserving street character. Rear additions are also popular on the deep lots backing onto the Humber River corridor, where setbacks and ravine regulations govern what can be built.
Yes. Many Humber Valley properties fall within or adjacent to Toronto's Ravine and Natural Feature Protection (RNFP) area. This imposes setbacks from the ravine edge, may require a ravine permit, and can trigger Toronto and Region Conservation Authority (TRCA) review. Kopman Build has experience navigating these overlapping approvals and will assess your lot's constraints before any design work begins.
Humber Valley is a premium renovation market. A single-storey rear addition typically runs $220,000–$420,000+ depending on size and finish level. A full second-storey addition on a Humber Valley bungalow runs $340,000–$650,000+. Ravine lot conditions, heritage character considerations, and premium material selections common in this neighbourhood can influence cost. Kopman Build provides detailed pre-construction estimates before any commitment.
A typical rear addition takes 6–10 months from permit approval to completion. A second-storey addition takes 8–14 months. For Humber Valley properties with ravine or TRCA involvement, permitting can add time to the front end — sometimes 6–10 months before construction begins. We give you a full, realistic timeline from the first consultation.
Kopman Build builds home additions across Humber Valley and Etobicoke. No-obligation consultation — we come to your property.
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