Circularity Housing

By TRACE Lab

Introducing a novel approach to residential design and construction that builds on current industry practices.

The Issue

Canada faces the dual challenge of delivering affordable housing while reducing the environmental impacts of construction.

environmental

The building sector is a major contributor to greenhouse gas (GHG) emissions, particularly through demolition activities.
Continued reliance on virgin materials accelerates the rate of natural resource depletion.

economical

Due to a lack of housing supply, Canadians — primarily first-time buyers —face a critical affordability challenge.

This project offers solutions to environmental and economic challenges in the Canadian homebuilding industry.

The Solution

This project addresses current challenges by increasing housing supply through material reuse and modular design for disassembly (DfD).

These approaches improve construction efficiency while reducing resource consumption, construction waste, and GHG emissions associated with material production, demolition, and new construction.

Translating CE principles into actionable and practical strategies for Canadian housing, this project demonstrates how CE approaches can be integrated while also maintaining affordability.

Circular Tectonics

A systematic examination of circular tectonics, documenting current industry practices, assessing their potential for adaptation within Canadian contexts, and identifying key considerations for implementation.

Explore Circular Tectonics

Photograph of a modern urban three-tower complex featuring cylindrical buildings, the shorter two of which each have one straight edge. The towers have reflective glass and metal panel facades. The scene features a partly cloudy sky and includes pedestrians, cyclists, greenery, and an industrial structure in the background, showing a blend of different building types in the area.

Picture of a modern, multi-story brick building with large rectangular windows and a flat roof, situated in an open paved area with young trees and benches. The building features a clean, minimalist design with natural light reflections on windows and sparse outdoor furniture

3D cutaway diagram of a building wall section showing construction layers around a window frame. The diagram highlights materials including wood, insulation, and exterior cladding with distinct textures and colors to illustrate assembly and structural components.

Photograph of a modern two-story wooden building surrounded by landscaped greenery and a garden with various plants and bushes. A vibrant red tree stands out in front of the building under a partly cloudy sky.

Photograph of three small contemporary houses with distinct architectural styles and materials, set against a partly cloudy sky and surrounded by trees. Houses feature large windows and varied roof shapes. The house on the left has a stone facade, the middle house has a facade of brick, and the house on the right has a concrete facade.

left: A tall modern apartment tower with clear balconies and large windows rises above a grassy area filled with trees on a sunny day. The high-rise building is framed by green trees and vegetation, with a clear blue sky in the background and a patch of ground covered with paving stones in the foreground. right: A tall, multi-story apartment tower with beige and red vertical stripes on the facade. Below are trees and parked cars along a street. The building has signage on its roof, and the scene is set under a partly cloudy sky.

Photograph of the Circular Retrofit Lab: a modern two-story building with beige paneling, cement structural frame, and large windows, surrounded by grass, trees, and a paved walkway. The scene includes a large tree in the foreground and another similar building partially visible in the background, showcasing the VUB campus setting.

Photograph of Research Houses Bad Aibling: three residential buildings, each three stories with light gray exteriors, one of masonry, one of timber, and one of concrete, as well as rectangular windows with arched lintels, situated along a paved pathway and a stoned fence. Buildings are surrounded with greenery near entrances and trees in the background under a clear sky.

New CE Methodology

Building on circular tectonics, a new methodology is developed to assist stakeholders in making informed decisions about the integration of CE strategies, with emphasis on selective deconstruction, material reuse, and Design for Deconstruction.

Explore the New CE Methodology

Prototypes

The proposed CE-based design methodology is used to develop three high-density, modular multi-unit housing prototypes using light wood-frame and mass timber construction.

Three high-density housing prototypes are developed to demonstrate the integration of DfD principles and the use of secondary materials, while evaluating their potential to support affordable, adaptable, and sustainable housing.

Explore Protypes

Demonstration Model

A one-to-one-scale demonstration model was developed to address the gap in the implementation of current circular designs in construction.

This model evaluates how DfD can be practically applied to a residential wall assembly. Through iterative design development, principles of reversibility, modularity, adaptability, and material value retention were highlighted to ensure that circular thinking was part of every step of the process.

This model shows that DfD can be a practical strategy for improving adaptability and recoverability of materials, confirming that CE principles can be implemented to ensure projects are adaptable for future reuse and repair.

View the Demonstration Model

10-15 STOREY | STEP 8 - SECONDARY STRUCTURAL ELEMENTS (EXTERIOR AND PARTITION LAYERS)

Reclaimable materials: Exterior cladding, façade systems, staircases and railings.

This step is focused on processing substructure materials within the Site layer, including reinforced concrete foundations, piles, and slabs-on-grade. These elements are deeply integrated and rarely recoverable as components. Instead, material recovery is achieved through crushing concrete for aggregate and separating embedded steel for recycling.

As the most permanent layer, the Site layer offers limited adaptability, and circular outcomes depend primarily on high-volume recycling strategies rather than component reuse.

10-15 STOREY | STEP 6 - SECONDARY STRUCTURAL ELEMENTS (EXTERIOR AND PARITION LAYERS)

Reclaimable materials:Exterior cladding, façade systems, staircases and railings.

This step is focused on removing façade and enclosure systems within the Exterior layer, including curtain wall panels, cladding units, and roofing assemblies. Panelised systems may be recovered intact if disassembled carefully, while metals such as aluminium and steel are directed toward recycling. As these systems are often integrated with both Services and Structure, their removal requires careful sequencing to maintain stability.

This step establishes clear separation between the building envelope and the primary structural frame.

10-15 STOREY | STEP 5 - ARCHITECTURAL FINISHED (PARTITION LAYERS)

Reclaimable materials: Floor tiles, wall finishes, ceiling systems and non-load-bearing partitions.

This stage is focused on separating high-volume materials within the Partition layer, such as suspended ceilings, gypsum board, and floor finishes. While reuse potential is generally limited, certain modular or demountable systems may be recovered.

Material separation is critical to prevent contamination and enable recycling pathways, particularly
for metals and gypsum. Removing these enclosing layers exposes the structural frame and service routes, allowing the transition from short- to long-lifespan layers within the deconstruction sequence.

10-15 STOREY | STEP 4 = SERVICES AND BUILDING SYSTEMS (SYSTEM LAYER)

Reclaimable materials: Electrical wiring and panels, plumbing lines and mechanical systems.

This step is focused on removing extensive Services layer networks, including vertical risers, ductwork, piping, and centralised mechanical equipment. Materials such as copper, steel, and aluminium are prioritised for recycling, while larger equipment units may be recoverable for reuse. Given their integration with multiple layers, including Structure and Exterior, services must be removed in a sequenced manner to avoid damaging adjacent materials.

This step reduces system interdependencies and enables the exposure of structural and enclosure layers.

10-15 STOREY | STEP 3 - LOOSE AND NON-LOAD BEARING INTERIOR ELEMENTS (THING LAYER)

Reclaimable Materials: Doors, hardware, cabinetry, and fixtures.

This stage is focused on extracting Stuff-layer materials at scale, including furniture, fixtures, and modular interior elements.

Standardised components such as doors, ceiling tiles, and demountable partitions are often present in large quantities and can support bulk recovery. As these materials are weakly connected to other shearing layers, they can be removed without compromising overall stability. However, variability across tenant spaces may affect reuse pathways, requiring careful sorting to maintain material quality and value.

10-15 STOREY | STEP 2 - HAZARDOUS MATERIALS ASSESSMENT

Reclaimable Materials: None

This step is focused on isolating hazardous materials distributed across several shearing layers, particularly within Services, Partition, and Exterior systems.

Asbestos-containing fireproofing, PCB sealants, and contaminated insulation are commonly embedded within structural protection layers and façade assemblies. These materials constrain the recovery of adjacent steel, aluminium, and concrete elements. Controlled abatement therefore enables the decoupling of contaminated layers, ensuring that structural and enclosure materials can be recovered without cross-contamination, which is critical given the scale and integration of these systems.

TRIPLEX | STEP 6 - SECONDARY STRUCTURAL ELEMENTS (EXTERIOR AND PARTITION LAYERS)

Reclaimable Materials: Exterior cladding, façade systems, staircases and railings.

This step involves dismantling materials located at the interface of the Exterior and Partition layers, including roof assemblies, brick veneer, balconies, and light timber framing.

Timber elements may be salvaged where connections can be reversed, while brick recovery depends on mortar condition. These components contribute locally to load distribution but are not part of the primary structural system. Their removal separates enclosure systems from the structural core, enabling access to higher-value materials within the Structure layer.

TRIPLEX | STEP 5 - ARCHITECTURAL FINISHED (PARITION LAYERS)

Reclaimable Materials: Floor tiles, wall finishes, ceiling systems and non-load-bearing partitions.

This stage involves removing materials associated with the Partition layer, including plaster, gypsum board, hardwood flooring, and interior finishes.

Selective dismantling allows the recovery of durable materials such as flooring and trim, while gypsum-based products are typically directed to recycling. As the Partition layer mediates between Services and Structure, its removal exposes concealed timber elements and mechanical systems, improving access for
further disassembly and enhancing the visibility of recoverable materials embedded in longer-lifespan layers.

TRIPLEX | STEP 4 - SERVICES AND BUILDING SYSTEMS (SYSTEM LAYER)

Reclaimable Materials: Electrical wiring and panels, plumbing lines, and mechanical systems

This step involves dismantling materials within the Services layer, including copper wiring, plumbing lines, compact HVAC units, and radiators. These systems are typically interwoven with the Partition layer but remain accessible within walls and floors.

Recovery focuses on high-value metals such as copper and steel, while certain components may be directly reused. Removing services decouples intermediate-lifespan systems from longer-lifespan structural elements, facilitating safer and more effective subsequent material recovery.

TRIPLEX | STEP 2 - HAZARDOUS MATERIAL ASSESSMENT

Reclaimable Materials: None

This step involves the removal of hazardous materials embedded within the exterior, partition, and services layers. Materials such as asbestos insulation, lead-based finishes, and mold-contaminated assemblies are isolated to prevent the contamination of recoverable materials. In Quebec, building materials from before 1990 are presumed to contain asbestos unless tested otherwise [1]. These hazards often affect interior finishes and service zones, and their removal enables the safe recovery of uncontaminated elements located in the Structure and Partition layers. This step separates contaminated from recoverable layers, allowing subsequent disassembly to proceed under safe and controlled conditions.

References

Gouvernement du Québec, “Preventing Health Problems Associated with Asbestos,” Gouvernement Du Québec, January 12, 2021, https://www.quebec.ca/en/health/advice-and-prevention/health-and-environment/preventing-health-problems-associated-with-asbestos.

TRIPLEX | STEP 3 - LOOSE AND NON-LOAD BEARING INTERIOR ELEMENTS (THING LAYER)

Reclaimable Materials: Doors, hardware, cabinetry and fixtures.

This stage involves the removal of materials associated with the Stuff layer, which comprises short-lifespan and loosely attached elements with high reuse potential.

Components such as furniture, appliances, lighting fixtures, doors, cabinetry, and radiators are extracted intact to preserve their functional value. These elements are minimally integrated with other layers, allowing efficient recovery.

Early removal reduces the risk of damage during subsequent operations and prevents contamination of these high-value components by materials from longer-lifespan layers.