Circular UrbanismInterventions for Urban Circular Ecosystems 
In Collaboration with Amber Peiying Han


Advisor: Keller Easterling
Location: New York; Austin; Vancouver
Yale School of Architecture, Thesis


Introduction

Circular Urbanism explores the existing networks and ecosystems within critical reuse infrastructure and how building materials move through them.

The adaptive reuse of buildings and the salvage of their components have continually evolved through innovations in design and technology, yet the broader network of recycled materials and infrastructure is equally important but less explored. As more cities focus on densification with the goal of creating a more sustainable and circular model of material consumption, the built environment is being utilized as a material bank with the potential to support future development and to minimize carbon footprint.
Global C&D Debris Percentage
US C&D Debris Percentage
The project begins with comparative urban analysis* and leads to site-specific interventions. Three North American cities—Vancouver, Austin, and New York—serve as experimental grounds, each at different stages of their transition toward “circular city”, and requiring distinct approaches. In Vancouver, a sustainable housing densification model was developed to address the city’s housing crisis and account for the material lifecycle. In Austin, material storage facilities have been reimagined as market destinations that reflect the city’s ebb and flow of construction activities. In New York City, three temporary installations were designed as educational platforms, strategically located in pocket spaces to maximize exposure to circular materials and reuse strategies. By applying hierarchical strategies (S⊆M⊆L) across different scales, this research proposes improved material flows based on each city’s context, reuse policies, and established infrastructure.

RotorDC, Brussels 
* Comparative Urban Analysis

The three maps highlight key infrastructure locations that are essential to the building material recycling process in three selected cities. The critical steps in material circulation include transport, storage, processing, marketplace activities, reuse practices, and salvage from deconstruction.


Left:Material Circulation Cycle; Right:Hierarchical Interventions

Existing Infrastructure in Three Cities


Methodology
Precedents Catalog

Phase 1: Precedents Study
The research begins by examining city-wide initiatives and circular material practices in architecture, including visits to cities in Belgium and the Netherlands, which are known for successful examples of circular design. The identified precedents are categorized by their role across the construction value chain.


Phase 2: Urban Analysis
Three North American cities—New York, Austin, and Vancouver—were selected for further analysis using a framework derived from previous research. Each city was examined in five key aspects: the state of deconstruction and salvage practices, the network of waste transportation, the number and types of processing facilities, examples of material reuse, and the market environment for salvaged materials.


Phase 3: Intervention Designs
Three proposals have been developed based on the current state of each city, with the intention of facilitating a shift toward circular construction practices.


New York City

S: Temporary Material Showroom
As of 2018, New York City recycles about 64% of its construction and demolition waste, while a significant portion of debris is still shipped outside the city to processing facilities or landfills. The city has a well-established network for outward waste movement, yet its internal waste circulation remains relatively weak, despite the huge potential market for reclaimed materials. In response to the city’s unbalanced waste network, the project presents three types of temporary material showrooms, advocating for more internal recycle and reuse awareness. These installations take shape using rental materials from deconstruction sites and salvaged material retailers. Situated within underutilized small lots, public parks, or near deconstruction sites, the structures are designed to exemplify reuse practices while also providing platforms for exchange and education. By utilizing a rental material model, these interventions create a new education stop within the existing waste stream, maximizing the potential impact of reclaimed materials.
Marine Transfer Station© Dattner Architects
Big Reuse NYC

Urban Analysis

Map of C&D Debris Infrastructure
Existing Infrastructure
Existing Circulation


NYC Existing C&D Debris Circulation

Design Intervention
Temporary Material Showroom

Proposed C&D Debris Circulation
New Material Flow



Temporary Showroom

Temporary Display Shelf


Small Lot Intervention


Urban Section-Circular Interventions


Austin
M: Material Marketplace & Storage
Austin ordinances require general contractors to reuse or recycle at least 50% of construction and demolition debris, fostering collaboration between deconstruction and recycling facilities. Additionally, the city has established online networks and physical marketplaces for reusing small objects, materials, and furniture.

Building on this strong foundation, Austin’s circular network can be further strengthened with dedicated material storage and marketplaces for building components. These spaces can be built near existing reuse stores and recycling facilities, reducing material transportation distances and creating a centralized reuse destination. Architecturally, the building is designed to adapt to typical warehouse steel structures, incorporating recycled items as partitions or enclosures while displaying them for sale. The material inventory itself shapes the building, serving as a dynamic representation of the city’s ongoing reuse efforts.
Austin Circular Economy Stody Map 
Center for Maximum Potential

Urban Analysis
Map of C&D Debris Infrastructure
Existing Infrastructure


Existing Circulation

Austin Existing C&D Debris Circulation

Design Intervention
Material Marketplace & Storage

Proposed C&D Debris Circulation
New Material Flow


Storage of Renew Fabric & Lumber (1/2)
Storage of Renew Fabric & Lumber (2/2)

Brick Wall (1/2)
Brick Wall (2/2)

Storage of Reclaimed Window (1/2)
Storage of Reclaimed Window (2/2)

Section-Material Marketplace & Storage


Vancouver

L: Community Land Trust Development Model
Of the three selected sites, Vancouver stands out for its proactive reuse of construction materials, driven by its abundant wood resources, mature lumber reuse market, and policies that equalize the costs of demolition and deconstruction. The city exemplifies those with advanced urban recycling infrastructure and strong circular policies. However, Vancouver faces a severe housing shortage due to limited land availability, rising housing costs, and gentrification. As the city revises zoning and explores strategies to densify single-family neighborhoods, we propose a housing development model based on collaborative ownership through community land trusts*.

This model empowers residents to decide how to develop the land and benefit from densification, while enabling planned deconstruction and reuse of building components on-site under community oversight. Temporary material storage facilities are established during construction, facilitating material exchange between communities. After development, these spaces can transition into material marketplaces or other community amenities, ensuring the continued circulation of recycled materials across different land trust communities.
Unbuilders
Salvage Vancouver

* Community Land Trust System




Community
: Single-family house owners who live within a specific geographic area agree to develop collaborative ownership of the land and decide what to build on top.

Land: The CLT retains the land, taking it off the real estate market and planing it under community control through nonprofit organization. Lot size and function can be planned  and determine by the community members.

Buildings: Apartment buildings and townhouses are constructed, with each community member owning two or more properties. Members can move into the new apartments and lease their other properties for rental income or development.

Materials: The CLT plans and control the deconstruction and construction process of the buildings, materials can be sorted, recycled, stored, and reuse on site. 


Urban Analysis

Map of C&D Debris Infrastructure
Existing Infrastructure
Existing Circulation

Austin Existing C&D Debris Circulation

Design Intervention
Circular Neighborhood Development Model

Proposed C&D Debris Circulation
New Material Flow

Pre-Development
Construction & Deconstruction
Post-Construction

© 2024.Weiqiao Lin