Specifying efficient use of materials and considering their impact from manufacture to disposal.
Implementing waste management
A simple way of understanding the different processes involved in waste management is through the 5 Rs.
There are many variations of this around, but the key elements can be summed up with the words:
- Reject – refuse to use wasteful products or materials at all, such as products that cannot be repaired, reused or recycled, when there are other options available. This also applies to excessive packaging.
- Reduce – ensure that a building is no larger than it need be. Reduce offcuts by designing to match standard product sizes, or locating a bathroom next to a laundry so hot water pipe length can be reduced.
- Reuse – keep hold of offcuts above a certain size and use them when a small piece of material is required. Relocate a building where possible rather than demolishing/deconstructing it.
- Repair – fix a product or material whenever possible rather than throwing it away at the first sign of a fault and buying a new replacement. When buying new products, choose products that can be repaired.
- Recycle – arrange for materials to be collected by a salvage company or taken back by a manufacturer to be reprocessed into new product.
Where none of the 5 Rs are possible, disposal at a landfill or waste facility is the last resort.
Applying the 5 Rs will lower the amount of waste that goes to landfills and reduce the demand for new building materials to be produced.
- design stage
- construction stage
- deconstruction/demolition stage.
Design must incorporate the principles of minimising waste by:
- allowing for a logical sequence of construction
- keeping the range of materials to a minimum
- using modular sheet sizes
- identifying and sourcing suitable recycled materials
- arranging services to be compact with minimum runs
- using excavated material to form landscape where possible
- selecting locally manufactured materials
- planning for end use and deconstruction.
Plan for end use and deconstruction by:
- specifying reversible jointing methods, e.g. bolted or screwed connections rather than welded joints in steel
- minimising use of composite materials such as coated materials and laminates as they are generally more difficult to recycle
- specifying materials that are easy to reuse or recycle even if they have a higher initial embodied energy.
Prepare a waste management plan: Prepare a waste management plan before beginning construction. From BRANZ REBRI you can download a waste management plan template.
Before construction starts:
- Plan locations for depositing and stacking materials.
- Ensure all subcontractors are aware of the recycling policies.
Ordering and obtaining materials:
- Order the correct amount of material – do not over-order.
- Plan for delivery as required to minimise storage time on site.
- Confirm dimensions before ordering materials/components.
- Minimise the number of trips to a supplier by getting everything needed in one trip.
- Use prefabricated materials and components where possible.
Storage and use of materials:
- Store materials so they are protected from the weather and potential damage.
- Centralise timber cutting and collect off-cuts.
- Confirm measurements before cutting or fabrication.
- Use recycled aggregate for concrete where possible.
- Use recycled steel for reinforcement where possible.
- Return surplus materials to the supplier to be recycled where possible.
Avoid repair work:
- Sequence work effectively.
- Set up an effective quality control system to monitor the quality of the work as it proceeds.
- Prevent damage to completed work by providing adequate protection, sequencing work effectively and using tradespeople who respect the work and finish by others.
Demolition produces more waste than at any other stage of a building’s life, and significant waste is generated when a building is renovated. The most effective way to minimise waste is to extend the building’s life by relocation or renovation.
When relocation and renovation is not an option, with careful planning, a significant amount of waste may be able to be reused or recycled during the deconstruction/demolition process.
Planning steps during the deconstruction/demolition should include:
- site and building survey
- make an inventory of materials
- prepare a deconstruction plan
Site and building survey: Review building plans, working drawings, and engineers’ reports to determine the materials and construction techniques used and to locate the existing services. Information can be obtained from the local council or the building owner.
Buildings suitable for deconstruction include:
- timber-framed buildings with large timbers and beams
- buildings containing native timbers
- buildings with architectural features such as multi-paned windows, architectural mouldings and panelled doors
- buildings constructed from high-quality brick laid with low-strength mortar, which allows relatively easy break-up and cleaning
- buildings incorporating high-quality reusable items such as steel beams or steel cladding.
To carry out the building survey, employ:
- a builder, carpenter or architect with expertise in the methods and materials of construction
- tradespeople experienced in repair/restoration work
- a structural engineer/materials inspector who can advise on the structural integrity of building components and/or the existence of hazardous materials that require special handling
- someone with knowledge of the salvage value of building materials on the local market.
When carrying out a building survey, use:
- inspection forms to ensure that you have collected all the information you need
- a camera – photographs are helpful in recalling important characteristics of the building and the site
- hand/power tools to look behind walls or beneath flooring to verify the size and condition of structural components or the existence of hazardous materials
- respirators or dust masks when any cutting, drilling or removal of materials is done.
Make an inventory of materials: Quantify each material type and evaluating to determine whether the material should be reused, recycled or disposed of.
Calculate the costs and savings associated with reuse, recycling and disposal. Include:
- payment for recyclable and reusable materials
- reduced landfill/cleanfill disposal costs
- reduced transport costs
- cost of time required for sorting or preparing materials for reuse or recycling.
Prepare a deconstruction plan: Prepare a deconstruction plan that includes:
- a list of building materials and components to be removed for reuse or for recycling
- a specification for the refurbishment work
- instructions regarding deconstructing methodology and sequencing.
The deconstruction plan can be used to tender, to provide information to the people involved in the project and in the application for a consent for demolition.
The plan should describe the:
- location of materials to be salvaged for reuse or recycling
- quantities of materials to be salvaged for reuse or recycling
- destination and/or intended end use of the building’s components, including appropriate disposal of residual waste
- deconstruction methodology and sequencing
- schedule for deconstruction
- location of storage areas (if materials are to be stored on site)
- security and protection measures for storage areas
- handling and removal procedures for materials and components.
Deconstruction/demolition process: The implementation of the deconstruction/demolition process should include:
- enough time within contract periods for dismantling
- clear identification of storage areas on site for each type of material
- designated storage areas that are convenient for workers
- protection of salvaged materials from the weather and potential damage
- dismantling components in reverse order to construction
- stripping interiors manually to reduce damage
- ensuring that all latches, hinges, framing and so on are kept with the component
- ensuring that all salvaged items are removed carefully from the site to reduce damage and contamination.
Updated: 28 February 2022