Lecture 12: Circularity - Notes

General Announcements

  • Master's student project presentations: June 13, 9 AM - 4 PM in J2 Studios. Exhibition opening at 4 PM.
  • Materials library potentially moving to J2 Studios and J214. Announcement to be made on Canvas.
  • Acknowledgment of traditional owners: Turrbal and Yugara people.
  • Designing on country framework by Kevin O'Brien. Concept of caring for country.
  • Trial exam next week; check timetable for final exam.

Review of Semester Content

  • Exam will cover lecture content and essential readings.

Earth and Soils

  • Major horizon layers.
  • Key components of each layer and their importance for the built environment.
  • Different types of rocks and their formation.
  • Examples and diagrams of healthy vs. urban soils.

Air and Water

  • Qualities of air and water.
  • Use of water in design and its effects on health and environments.
  • Case studies.

Concrete vs. Cement

  • Mixtures, ingredients, and recipes.
  • Standard concrete = Portland concrete.
  • Concrete good in compression.
  • Steel reinforcement needed for tension.

Structural Types

  • Anatomy of different structural systems.
  • Example: Maisons Domino by Le Corbusier.

Timbers and Walls

  • Difference between hardwood and softwood.
  • Australian species in both categories.
  • Timber's cellular structure and reaction to moisture (shrinkage).
  • Difference between spanning and supporting elements.
  • Rule of thumb: Spanning element (beam) is taller than it is wide due to bending; supporting element (column) has a symmetric cross-section.
  • Wall structures: Top and bottom plates, studs (jack stud, jamb stud), lintels, and nogging.
  • Stiffness achieved through bracing (triangles).

Plants and Corridors

  • Ecosystem services provided by plants.
  • Key features for protecting trees during construction.
  • Tree planting diagrams and case studies.

Metals and Roofs

  • Beams and trusses.
  • Anatomy of a truss: Top chord, bottom chord, and web (zigzagging triangles).
  • Truss elements primarily take axial forces.
  • Roof structures: Ceiling joists, rafters, top plates.
  • Stiffness achieved through bracing.

Plastics

  • Regular plastics and bioplastics.
  • Properties, pros, and cons.

Stairs

  • Importance of knowing stair formulas.
  • Calculating number of risers and treads.
  • Understanding DDA (Disability Discrimination Act).

Glass, Windows, and Doors

  • Properties of glass.
  • Types of glass.
  • Reasons for glass failure.
  • Methods for strengthening glass.

Sound and Acoustics

  • Importance and measurement.

Circularity

  • Building sector contributes ~10% of Australia's GDP but also produces 87 tons of waste per million dollars of economic value.
  • Construction demolition waste has surged to 61%.
  • Approximately 17m317 m^3 of waste is generated in the construction of a house, costing about $10,000 to send to landfill.
  • Climate change requires a fundamental shift in the building and construction sector.
  • Current linear economic model: Take, make, waste.
  • Need three Earths' worth of resources to accommodate global population growth but we only have one.

Embodied Energy vs. Operational Energy

  • Both contribute to a project's overall carbon footprint.
  • Importance varies depending on building type, materials, and operational practices.
Embodied Energy:
  • Also known as upfront carbon.
  • Energy required for all processes associated with a product's life cycle, including raw material extraction, manufacturing, transport, construction, maintenance, renovation, and end-of-life disposal.
  • It is a onetime energy input.
  • Life cycle assessment considers product stage, construction stage, use stage, and end-of-life stage.
  • Global Warming Potential (GWP) varies for different materials.
Operational Energy:

  • Energy needed to operate a building during its use phase, including heating, cooling, lighting, and appliances.

  • Balance between embodied carbon and operational carbon emissions has shifted in some countries due to renewable energy.

  • Example: New fish market in Sydney with timber imported from Europe; carbon footprint was lower due to Australia's coal-based power grid.

Circular Economy

  • System where materials never become waste and nature is regenerated.

  • Products and materials are kept in circulation through maintenance, reuse, refurbishment, remanufacture, recycling, and composting.

  • Tackles climate change, biodiversity loss, waste, and pollution by decoupling economic activity from the consumption of finite resources.

  • Butterfly Diagram illustrates biological and technical cycles.

  • Design for disassembly and material stewardship are important practices.

  • Handbook to Building a Circular Economy by David M. Cheshire is a key resource.

  • Principles: Keeping materials and resources in use and retaining their value.

  • Strategies: Design for adaptability, design for deconstruction, using circular materials, and resource efficiency.

  • Australia has a circular economy framework that identifies the build environment as a key industry.

Nine R's Framework

  • Hierarchical order for circular economy strategies:
    1. Refuse: Make product redundant.
    2. Rethink: Make product use more intensive.
    3. Reduce: Increase efficiency in products and consumption.
    4. Reuse: Reused by another consumer.
    5. Repair: Repair and maintain.
    6. Refurbish: Restore an old product.
    7. Remanufacture: Use parts of discarded products into new product with the same function
    8. Repurpose: Use the discarded product or its parts in a new product with a different function
    9. Recycle: Shred the stuff
    10. Recover: Incineration of material with energy recovery.

Key strategies include designing out waste, designing for disassembly, designing for adaptability, material selection, and shifting towards waste as a resource.

Planetary Boundaries and Carbon Budget

  • Stay within planetary boundaries; six of nine have been transgressed.
  • Global carbon budget: Need to stay under 1.5 degrees of warming.
  • Australia needs to reduce carbon emissions from 574 million tons to 8.23 million tons.
  • Typical houses produce 4.61 tons of carbon; need to get to 0.63 per square meter of a new build.

Project Examples

People's Pavilion (Arab):
  • Designed for disassembly and reuse with no waste.
  • Cladding made of recycled plastics.
  • No permanent connections.
  • Recycled glass partition walls.
  • Pine wood load-bearing structure.
  • Fits in a few trucks for transport.
Upcycle Studios (Lendager Architects, Denmark):
  • Made out of reclaimed building materials.
  • Cut existing brick walls from buildings doomed to be demolished.
  • Saved 40-45% of CO2 emissions; 1,000 tons of waste turned into building materials.
  • Created jobs.
Quay Quarter Tower (BVN Architects and 3XN):
  • Adapted an existing tower rather than demolishing it.
  • Extended floor plates and reused existing structure.
  • Won the World Tall Building Award.
Shoalhaven Shire Resource Recovery and Learning Center (Terroir Architects):
  • Uses local resources; resource recovery and learning center.
  • Gabion walls with concrete waste.
  • Material strategy based on local resources.
    • Glass aggregate building product (repurposing).
    • Lifting straps for shading structure.
Terroir Architects' Hobart Studio Refurbishment:
  • Reused timber instead of soft stripping.
  • Refurbished materials.
  • Considered the aesthetic and history of materials.