Material Use

By taking a few simple steps to minimise waste during construction, a designer and a builder may be able to reduce costs, save time, and make the construction process go more smoothly.

Before you start

Designers should make waste minimisation a condition of the building contract. Before construction is started, have the builder develop a simple waste minimisation plan. This should assign responsibilities for waste minimisation, estimate the types and amounts of waste that will be produced, identify what will happen to each type of waste (including what types of waste can be  re-used or recycled), set targets, and state where materials will be stored.

The REBRI website has a simple waste management plan template (PDF, 21kb).

Ensure everyone on site is aware of the importance of waste minimisation and understands how it will be managed – site staff buy-in is essential. Put a list of materials that will be re-used/recycled up on a site noticeboard and make sure all workers/contractors know about it. As well as explaining your waste minimisation plans before you start, builders can encourage buy-in by praising staff for a job well done.

Ordering/obtaining materials

To minimise waste:

• order the right amount of material – over-ordering wastes materials and money
• plan for ‘just in time’ delivery to reduce the risk of damage while the material is being stored on site
• plan carefully before you visit a supplier – getting everything you need in one trip, instead of making lots of small trips, will save you time and money
• where possible, use prefabricated materials and components, and ask suppliers to make components to the right size to minimise on-site cutting.

Storing and using materials

To minimise waste:

• store materials properly, so they are protected from the weather and from other sources of potential damage
• provide bins for waste that will be re-used or recycled, and make sure the bins: are clearly labelled on each side; are in suitable locations (easily accessible for workers and collectors, but out of traffic areas); are picked up only when full
• centralise timber cutting and provide a place for off-cuts – these can be re-used
• provide a place for left-over concrete – this can be re-used, for example in footpaths or for fill
• keep the site tidy – this will keep it safe, as well as making it easier to find offcuts or other materials that can be re-used.

NB: the Recycling Organisation of NZ website has downloadable standard labels for recycling bins.

Record the amounts of material salvaged and monitor costs/savings in a site diary. The REBRI website has a downloadable waste management record template (PDF, 624 kb).

Preventing rework

Rework or repair of damage that has occurred before a building is completed is a significant cost to the New Zealand building industry – the cost of any work that has to be redone, repaired or replaced is money out the door. Rework can be reduced by:

• having an active quality control system in place to monitor quality as work proceeds
• sequencing work effectively
• ensuring trades have respect for the work and finishing done by others
• protecting finished work where other trades will be working in the vicinity or above the completed work
• checking on-site measurements before commencing fabrication.

For your clients

To help your clients understand the benefits of reducing construction waste, refer them to www.smarterhomes.org.nz/construction.