Construction, Renovation and Demolition Waste (CRD)
What is it?
Construction, renovation and demolition (CRD) sites typically involve large quantities of similar materials that can be easily separated. The main components are: wood, inert materials (concrete, brick or block), metals, building materials, and miscellaneous (plastics, glass, roofing, insulation) which is shown in the pie chart below. Many communities in Saskatchewan accept concrete and asphalt for crushing and reuse at their landfills. Several additional province-wide and community-based companies accept other materials such as shingles and brick for crushing or reuse.
(Source: March 2001 WasteWatch)
What is the issue?
It is estimated that anywhere from 25 - 40 percent of the national solid waste stream is building-related waste. (American Institute of Architects) The cycle of construction, renovation and demolition (CRD), generates enormous amounts of leftover materials with a huge potential for reduction, reuse and recycling. An average demolished house can create up to 42 tonnes of waste. Although demolition generates the bulk of CRD waste, potential exists for waste reduction in the construction sector as well. Construction of a typical (U.S.) 2,000 sq ft home generates about 3,636 kg of wastes:
Solid sawn wood - 727 kg (20%)
Engineered wood - 636 kg (17.5%)
Drywall - 909 kg (25%)
Cardboard (OCC) - 273 kg (7.5%)
Metals - 68 kg (1.9%)
Vinyl (PVC) - 68 kg (1.9%)
Masonry - 455 kg (12.5%)
Hazardous materials - 23 kg (0.6%)
Other - 477 kg (13.1%)
Cardboard makes up a huge portion of construction waste because it is used as packaging.
Many of these materials are recyclable and could, with some planning, be reduced, saving both material and disposal costs. Deconstruction, an alternative to traditional demolition, involves manually disassembling buildings to maximize the salvage. Deconstruction goes beyond cherry-picking (removal of decorative components such as antique doorknobs, fireplace mantles, and banisters) and includes the recovery of structural timbers, wood framing, sheathing, and even bricks. Deconstruction is labour intensive. It relies mainly on hand tools and people power to take buildings apart. Even though it takes longer than traditional demolition, the trade-off is job creation, business development and waste diversion. Habitat for Humanity deconstructs rooms and houses to generate materials for sale in their ReStores.
Where can it go?
CRD waste is bulky, heavy and generated in large amounts but much of it can be reused or recycled. The challenge for all of us is to find ways to take advantage of all that potential, and to do what we would like to do for everything—turn a waste into a resource. Habitat for Humanity accepts materials such as drywall, toilets and window frames for resale at their store. Please visit our Waste Reduction Hub to find a location near you that can help you with your recycling needs.
What happens after?
The materials are salvaged and reused for other projects or are recycled into new resources. Crushed concrete and masonry can be recycled and used in road construction. Shingles can be ground up and used in asphalt. Recycled lumber is ground up as well and used in landscaping and other outdoor projects. Drywall, depending on the size, can either be reused in a different project or separated into its various components and recycled. Metal and vinyl siding can be recycled and used in new products. All of the cardboard used in packaging can be diverted from the landfill by recycling it.
How can I reduce?
- Design building dimensions to correspond with standard material sizes, especially lumber. This has the potential to reduce the amount of materials wasted by about one third.
- Order materials to optimally fit your needs; try to avoid having excess materials delivered to the project site. This will reduce the amount of waste produced and the cost of the project.
- Work together with your suppliers to reduce unnecessary packaging on materials, or ask if they can provide reusable/returnable packaging.
- You can also work with suppliers to buy back any unused supplies. This can be beneficial to you, your supplier and the landfill.
- Consider deconstruction techniques that can be used to prepare your site for renovation or construction. In some communities, deconstruction auctions are being used effectively to move building materials into the reuse market.
- Consider purchasing products from local salvagers before looking for new ones. You may be surprised to find that many of them offer cabinets, doors, windows, and flooring that are in good condition for great prices.