Construction waste: Low hanging fruit

New laws in Portland, Oregon that mandate the deconstruction of historical buildings will not only reduce waste in the construction, but will generate new sources of salvaged and recycled building materials.

Portland City Council passed a law in February that requires developers to fully deconstruct, rather than demolish, homes designated ‘historical’ or built before 1916. Deconstruction involves the methodical disassembly of a house to maximise salvage of materials such as door frames, windows, bathroom tiles and inlaid wooden floors for reuse. The City of Portland even offers deconstruction grants to encourage alternatives to the wrecking ball and to increase material salvaging.

Here at Sanctuary the news of the deconstruction laws in Portland piqued our interest in the salvaging situation closer to home. During 2009-10, there were 21.6 million tonnes of waste received at landfills across Australia and it is estimated that about 30% of this was construction and demolition waste.

Lara Knight publishes The Junk Map, an Australian website with a building demolition resources section. Lara says, “Deconstruction incentives are something I’d love to see applied in Australia. The waste of good quality, reusable materials in standard demolitions is phenomenal. Yet salvage specialists are struggling to keep up with demand for recycled hardwoods and heritage bricks.”

Recycling and upcycling is on the rise in Australia. Recycled timber is popular for furniture, flooring, and design features like cladding and landscaping. Vintage industrial furniture and storage is being repurposed for commercial fit outs and home decor. There are few deconstruction businesses operating in Australia, but Lara says demand is growing.

“People are starting to question machine demolition. Readers often ask me who can strip out timber floors, doors, windows and quality fittings because they’re concerned about waste.”

Donna Luckman, CEO at the Alternative Technology Association (publisher of Sanctuary and ReNew) says, “Not only does the deconstruction of a home cut down on waste going to landfill it fills a demand for recycled building materials.” She said the ATA frequently received queries from homeowners who were looking to purchase second-hand building materials for their home or garden. “It is often difficult for homeowners to decide whether to demolish and rebuild or to renovate. Knowing that a home can be pulled down with as many resources reused as possible can help home owners reduce their environmental footprint. It also makes a nice connection between the old and the new.”

Over to you: Open source housing

Marcela and Rob eye the neatly stacked piles of timber on the bare earth and ponder the detailed instruction manual. The collections of uniformly sized shapes wait idle for the exact configuration which will bring them to life. These beams and hooks will not become a bed, or even a kitchen, but their new house.

The above scenario, while fictional, might not be as unlikely as it sounds, if a global scheme to bring high quality design to the people takes off. WikiHouse is an open-source building platform that promises a fully constructed house in as little as a week, without the use of skilled labour or anything more than basic tools. The freely available architectural plans can be applied digitally to a computer controlled material cutter (CNC machine) to create precisely measured materials from locally sourced, standard products such as ply.

New Zealand WikiHouse chapter co-founder, British expat Martin Luff, was motivated by disaster. Living in Christchurch when the city was struck by a series of catastrophic earthquakes in 2010 and 2011 – and which continue to hold parts of the small city in varying states of limbo – he decided to contribute to the rebuild effort. He would turn his product and digital design expertise to houses, with the idea of creating a blueprint for a better kind of building.

“A lot of the houses that were being built pre-earthquake were poor quality, unaffordable and just substandard, and I thought they shouldn’t be,” Martin says. “I had the skills and therefore in a way I felt obliged – we are in the top one per cent in terms of education and opportunities compared to those less fortunate – and I thought, no one else is having a go, so I should.”

Martin teamed up with fellow designer Danny Squires and together they formed Space Craft Systems, the New Zealand arm of the UK-based and now global WikiHouse movement. The start-up is now working to take its small proof of concept structure through to a fully finished demonstration house.

The demonstration house aspires to Passive House standards; with carefully controlled ventilation, high levels of insulation and low-embodied-energy materials, but the commitment to sustainability is broader than the design itself, Martin explains.“We wanted to go beyond sustainability and to think about restorative systems – looking at all aspects,” he says. “So in terms of economics, for it to be self-sustaining, for it to happen on a sustainable scale, and of course environmental sustainability.” In the long term they plan to adopt a comprehensive framework such as the Living Building Challenge to measure their success, with a set of monitoring systems to be built into the design and post-occupancy evaluations to help refine the process.


A builder works on the frame for the Farmhouse in the UK Midlands – the first two-storey WikiHouse to be lived in, designed by Architecture 00. The components of the WikiHouse system are created to exact measurements with the use of CNC machining to fit together without nails and the use of more than basic tools.

While sustainable design experts are generally in favour of anything that normalises green building, some have concerns about the open- source movement. Melbourne University ESD expert Dr Dominique Hes sees a danger in passing on the building of houses to non professionals. “Many of the crucial elements of sustainable design could be lost,” she says.

Dominique sees more potential in the prefabricated housing model, which has been in practice in Japan for many years and is now gaining traction locally. In such projects, “there is a database of 50,000 home components, tied to a manufacturing base, the designer sits down with the client and designs their home with them using these components and the site,” she says. “The result is an efficient, prefabricated, customised home that is quick to build.”

She also cites the work of Castlemaine-based architect Geoff Crosby who is developing an apartment complex, also to the stringent Living Building Challenge standards, as a good model for replication (see more on the Living Building Challenge and prefab housing in Sanctuary 31). Dominique is acting as an advisor to his projects, and says they led what will be the first ecological survey of a pre- developed site with the aim of “healing and contributing to local ecology” during the build.

Geoff suggests that while open-source design could work well in some contexts, he is wary of a stock standard approach. While some aspects such as the right orientation could be easily controlled, he says it is hard to standardise character and site-appropriate attention to a building’s environmental impact. “Architecture isn’t like product design, it is integral to place – architects should act as mediators between people and their location to get the best outcome.”

He agrees there is a need to make comfortable and well designed homes accessible to more people, but suggests that rather than offering off-the-shelf solutions, experts in the field should think more about knowledge sharing.


A render of the ‘microhouse’ one of the available open-source designs by WikiHouse. New Zealand chapter co-founder Martin Luff says the WikiHouse concept aims to create adaptable designs that can suit changing needs throughout their lifetimes. “Building only what you need when you need it with the ability to easily change it when you want has huge benefits for lowering price to entry and ongoing financing costs.”

One of the most significant boosts to open-source housing design in Australia has come courtesy of the federal government. Your Home, part of the Department of Industry, Innovation and Science, released the first of its free high-performing house plans in September 2015, and report they have attracted a “huge amount of interest.”

The one-storey design is available as three or four bedrooms, as part of its Design for Place initiative. Spokesperson Bronwyn Pollock says that the plans need to be adapted by a draughtsperson to meet the needs of the local council, allowing the application of understanding of local conditions. The plans come with modifiable specifications for each capital city and seven design principles including orientation, shading, ventilation and natural light. Bronwyn says the program aims to make sustainable design accessible to those who don’t have access to an architect or designer, and to demonstrate that a comfortable, energy-efficient house needn’t cost more.

“The tendency in current building is to maximise size over functionality. The designs are intended to show how a well-planned design can be adaptable and serve the different needs of your household over time, while still being energy-efficient.”

She says a number of owners have made Your Home aware of their intended use of the scheme, with several revised plans currently sitting with various councils for approval.

Prefab NZ also sees promise in the open-source future and is running a design competition to produce an open-source ‘bathroom pod’, which could be added in a variety of contexts anywhere in the world.

While open-source house plans may not have caused the revolution some have anticipated, it’s hard to deny a shift in the accessibility of architecture. The potential for shelter to be created to a guaranteed standard without project-length expertise means that we could be closer to (at least one version of) the project home of the future.


Paper Houses is an open-source architecture platform which offers professionally designed energy-efficient house plans for free. Plans available include the Bolt House, the creation of Panorama – a Chilean design duo made up of Nicolás Valdés and Constanza Hagemann. It is designed for sloping land, which is often more affordable.


Australian earth builder and thermal assessor Luke Mahony has made some of his house designs open-source and freely available. For Luke it is about spreading the knowledge and benefits of a material he is passionate about and allowing it to be produced with local labour and materials.


In the zone: Zoning your garden

Water zoning – the practice of grouping plants based on their watering needs – is one of the most effective design strategies for the sustainable garden.

Water zoning considers a plant’s specific needs and its suitability to a particular climate. For me, it’s that last part which is the key to successful sustainable garden design. For a well-zoned garden, you  need to understand your local climate and the nuances of your site, especially rainfall patterns.

Plant nurseries, designers and garden books can help you to select the right plants for each water zone in your garden. Terms like ’drought tolerant’, ’hardy’, ’great for wet areas’, and ’perfect rockery plant’ are used to describe how plants perform in different growing conditions. Botanical descriptions can also highlight the unique characteristics of individual plants, helping you to understand their suitability for a particular garden style.


Well matched species such as sedum ‘autumn joy’, silver grass and euphorbias make for great perennial borders in areas with full sun and well drained soils.

To get started, research where your garden sits in the spectrum of Australian climate types. Knowing the macro- and micro- climate of your garden will help you to understand your site’s monthly rainfall, average temperatures, the likelihood of frost and the prevailing seasonal winds and storm conditions.

Almost all of the information you need to get an understanding of the long-term climate conditions in your region is readily available on the Bureau of Meteorology website. State government websites for natural resources, primary industries or land and water can also help you to identify the natural soil conditions for your region, sometimes down to your local area. For most sites, you’ll also need to take a walk to get a handle on the specific conditions you might experience in your suburb or street.

Take note of the various areas of sun and shade in your garden, and look for overly dry or wet spots. These might indicate problems with drainage and are potential zones for plants suited to drought conditions with periods of inundation, such as river red gums, swamp banksias, callistemon little John or knobby club rush.

Also take note of the dry shade areas – these are ideally suited to plants like clivea, plectranthus, Matapouri Bay or rock lily and the oyster plant.

Areas with naturally good drainage, a mix of sun and shade and good soil moisture are perfect for a broader range of plants, like herbs, vegetables, fruiting shrubs and trees and ornamentals. Plants like blueberries, lemons, oranges, mixed greens, roses, gardenias and turf grasses all perform with well-drained moist soils in full sun to semi shade.


Species such as gymea lily, lomandra, prostrate and shrub form grevillea and banksias work well on higher ground such as walls, rockeries and dryer slopes.

Explore your neighbourhood on a range of days in different seasons to get a sense of the extremes that your garden will need to cope with.

Successful local gardens, including parks and botanic gardens, can offer invaluable inspiration for your own backyard. Pay attention to the plants that appear naturally resilient to the local climate. I find gardeners are often more than willing to share their successes; by observing and asking, you’ll glean local knowledge on what grows well where. Sometimes you might even come away with a bucketful of locally conditioned plants perfectly suited to your micro-climate.


Mass planted, low water users like tolerant groundcovers are well suited to the zoned garden. Lambs’ ears have slightly furry silvery leaves that reflect the sun’s heat, and also form a slight microclimate the slows the wind speed over the leaf, limiting water loss.

Armed with local and regional knowledge, group your selection of plants according to their preferred growing conditions (sun/shade, frost); soil type; use (edible/ ornamental), and maintenance (high/low). You can then further group these plants into their need for water: high water users such as leafy greens; moderate users like fruit trees and low water users, including native shrubs and groundcovers.

Take the information you’ve gathered and create a map or plan of the natural water and exposure areas of your garden. Place the plants you’ve grouped by water need into the corresponding areas of your garden.

One of the most effective ways to zone plants is by mass planting two or three species in large drifts or groups. This keeps plants with the same water needs and growing conditions together, allowing you to efficiently water those areas that broadly need it, while avoiding those areas that don’t. In essence you’ll create a planted garden that matches the micro-climate of your site.


Grow what where, Natalie Peate, Gwenda Macdonald & Alice Talbot

500 Plants: Great Australian favourites for your garden, Angus Stewart

Dry Gardening Australia: Sustainable drought-proof gardening from the soil up, Jonathan Garder & Sarah Baker

The new shade garden: Creating a lush oasis in the age of climate change, Ken Druse

Michael Tanner is a designer and horticulturist with a lifelong passion for making sustainable, beautiful and liveable gardens.

DirtSong Michael Tanner Sustainable Landscape Designs