Introduction
Located in one of Toronto’s most dynamic residential areas, the 81 Massey Street project showcases how intelligent engineering can breathe new life into an existing structure. What began as a single-storey bungalow is being transformed into a four-unit multiplex (quadriplex) — a modern, efficient, and structurally independent residential building designed to maximize space, comfort, and long-term value.
This project highlights Q Engineering’s expertise in structural design, architectural coordination, and foundation reinforcement, all while meeting the City of Toronto’s strict residential building standards.
Project Overview
Type: Residential Multiplex (Conversion & Addition)
Location: 81 Massey Street, Toronto, ON
Scope: Structural and architectural design, underpinning, addition of second and third floors, and rooftop terrace
Client Goal: To convert an aging bungalow into a modern four-unit residence while preserving as much of the existing structure as possible.
The client, Mr. Nadjib Aouchiche, envisioned a multi-unit home that combines functionality, durability, and future flexibility. With limited lot space in Toronto’s downtown core, the project required a smart structural approach — one that could accommodate multiple residential units while reinforcing the original foundation.
Engineering Challenges
Redeveloping an older bungalow into a three-storey multiplex posed several complex structural challenges:
-
Preserving the existing structure: The original bungalow’s framing and foundation couldn’t carry additional loads from the new upper floors.
-
Minimizing disruption: The design needed to limit demolition and excavation to preserve the basement and existing main floor.
-
Creating a new independent frame: A modern structure had to be introduced without overloading the old one.
-
Designing for future adaptability: The client requested that the new foundation and framing support a potential half-floor and rooftop terrace in the future.
-
Logistical coordination: The property’s tight downtown footprint required careful planning for site access, underpinning, and excavation.
Q Engineering’s Solutions
Q Engineering redesigned the project from the ground up — literally. Our team replaced the initial conventional framing concept with a steel-and-concrete hybrid structural system, ensuring strength, flexibility, and longevity.
Independent Structural Framing
-
Introduced HSS steel columns (6”x6” and 5½”x5½”) anchored to reinforced concrete footings in the basement.
-
Created a self-supporting steel skeleton that passes through the entire height of the building — from the basement to the rooftop — allowing the new second and third floors to sit independently of the original structure.
-
Used W8x15–W8x35 beams and LVL joists to distribute loads evenly while maintaining interior openness.
Foundation & Underpinning
-
Underpinned and reinforced the existing basement to achieve a legal 8-foot ceiling height and improve load-bearing capacity.
-
Added new footings (4’–5′ wide) designed to support potential future vertical expansion.
-
Installed a sump pump and drainage system to manage groundwater and prevent moisture intrusion.
Efficient Multi-Unit Layout
Each of the four levels — basement, main, second, and third floors — was designed with mirrored layouts for construction efficiency and cost reduction.
-
Unit 1 (Basement): Two bedrooms, open-concept living space, large egress windows, and independent mechanical systems.
-
Units 2–4: Open-concept living/dining/kitchen areas, multiple bedrooms, and private access to the rooftop terrace.
-
Rooftop: Reinforced structure capable of supporting a hot tub, outdoor kitchen, and garden area.
Architectural Coordination
Working closely with the architectural designer, Q Engineering ensured that all new framing, egress routes, and privacy walls met Ontario Building Code (OBC 2012) standards.
Every connection, beam, and post was verified for constructability — balancing safety, aesthetics, and cost efficiency.
Outcome & Expected Impact
The redesigned structure is currently in the advanced design and permit phase, representing a modern reimagination of downtown residential infill.
The project demonstrates:
-
A scalable and durable design that supports future expansions.
-
A reduced construction timeline through prefabricated steel framing.
-
Compliance with OBC and City of Toronto permit requirements.
-
Enhanced property value through conversion from a single dwelling to a four-unit income property.
Beyond its technical achievement, 81 Massey Street embodies what Q Engineering stands for — innovation, precision, and a commitment to helping homeowners unlock the full potential of their properties.
Conclusion
The 81 Massey Street multiplex project is a testament to how strategic structural engineering can transform outdated properties into modern, high-performance residences.
Whether it’s an addition, renovation, or a complete redevelopment, Q Engineering provides the expertise, design accuracy, and technical oversight to make every residential project a success — from concept to construction.