Weighing up the cost

With landfill costs going through the roof and significant building material inflation in recent years, astute builders are starting to review how they approach rebuilds and major renovation projects.

The traditional approach of demolishing existing structures and carting the waste to the dump doesn’t stack up like it used to. In many cases, deconstruction is a much better option whereby valuable materials and fittings can be salvaged to be re-used, re-purposed or on-sold.

A new approach
While there is no doubt that deconstruction is a better option environmentally, there has always been debate about the economic benefits, with demolition generally considered the cheapest option. But that’s changing.

In 2020, Kāinga Ora carried out a public housing deconstruction project at a Mount Albert development in Auckland known as Martin Leone.

As part of a pilot programme, 8 of the 10 existing houses were removed using deconstruction, and two homes were lifted offsite for resale—the project resulted in an 85% diversion from landfill. Crucially, the analysis showed the cost and duration of the deconstruction were similar to conventional demolition.

Nowadays, a better choice is to relocate the house or deconstruct it to recover valuable components.

High-value components
As the land value in established residential areas increases, it often makes sense to demolish the existing house on the site and build a new one, or where regulations allow, build two or more homes.

Nowadays, a better choice is to relocate the house or deconstruct it to recover valuable components that cannot easily be sourced. Some examples include native timber framing, joists, trusses, weatherboards, flooring, multi-paned windows, doors, architectural mouldings, unique plumbing and electrical fixtures.

Kitchens and bathrooms
With kitchen or bathroom renovations, the same principle applies. Cabinetry, appliances, plumbing  and light fittings can all be re-used. Before you start a project, talk to your customer about the benefits of deconstruction and make a plan together.

There will be charity groups within your community that will be happy to help. Another option is your local recycling centre; most centres have shops that sell usable household items and building materials.

Other options include Trade Me, Facebook Marketplace, or exchanging materials through sites such as Freecycle nz.freecycle.org, Waste Exchange nothrow.co.nz or by using the Civilshare app civilshare.co.nz.

>> To find out more about managing your construction waste, visit the construction waste section at makethemostofwaste.co.nz <<