Denise Bester: Too much waste in building industry

Construction, maintenance and renovation of buildings account for around 40 per cent of the world's material flows, so it's always sad to see an old building reduced to a pile of rubble

We know our resources are finite, so to continue to demolish buildings is not particularly smart when all those materials end up in a hole in the ground.

While the Ministry for the Environment says that at least 26 per cent of the waste in our landfills is from buildings, the Organisation for Resource Efficiency in the Building and Related Industries says that up to half of all landfill waste is from construction and demolition. This both uses up landfill space and contributes to pollution.

To counter this problem, disassembly is becoming more common, with various building-waste exchange systems already active.

The practice has many environmental and social benefits but often much of the salvaged material is unusable, damaged by techniques used during construction.

This is why some designers are aiming to construct buildings with disassembly in mind. They're adopting the "cradle to cradle" philosophy, where the whole lifecycle, or more aptly, series of lifecycles, is considered in the design phase.

Designers incorporate planning for future renovations and eventual disassembly, which cuts down on waste and prolongs the life of the building.

An example of such a design is the Design-for-Disassembly House in Atlanta in the US. This house, made from standard building materials and conventional building methods, is constructed in a way that will make it easy eventually to take it apart and reuse it.

To encourage such thinking here, the Green Building Council has a green star rating system which rewards developers for using resources as efficiently as possible and includes rating categories in materials and energy.

* Denise Bester is from sustainable living website www.ecobob.co.nz