Mawson Lakes Residential Development

Objective:

To ensure that residential homes built at Mawson Lakes demonstrate world's best practice in construction material lifecycle analysis, energy conservation and quality of environment; and

To assist in the development of an Australian export industry in modular housing, technologies and components.

Strategic fit:

This project is in accord with MFP Development Corporation's broad objectives, which include:

• To demonstrate conservation of resources and new energy saving technologies.
• To achieve business development in resource conservation and environmental technology.
• To engender and monitor community, industry and regulatory support for the Mawson Lakes development.

Discussion:

Previous demonstration housing developments undertaken with the support or sponsorship of MFP Development Corporation (e.g. New Haven) have focused on energy conservation issues rather than life-cycle analysis of the built form. For example, previous homes have utilised conventional concrete footings and frequently double clay brick construction, despite the very high energy consumption required to produce these two significant inputs to the construction industry. The reason for this is the known market acceptance of these products and the reluctance to invest in alternative construction technologies, despite their obvious savings in energy consumption. This project aims to redress this balance - by presenting alternative construction materials with a view to popularising their adoption for the Mawson Lakes Development.

The following outcomes are expected:

• encouraging innovation and the development of new technology in building and construction;
• establishing benchmarks against which goals for the achievement of sustainable development for the built environment can be measured;
• developing an internationally competitive advantage for the Australian building and construction industry.

Introduction

Many of the building and construction materials and techniques used today remain unchanged from the methods used for house construction in the 17th century. Burnt clayware for example has been found dating from 15,000 BC. Clay bricks evolved from the traditional mud and straw through mud brick to sun dried clay and, as energy forms such as wood became more widely used in Egyptian times, kiln fired bricks. Similarly the Portland cement used in footing construction has evolved from the burnt lime originally developed for protecting mud structures from the weather. By mixing with clay and shale, the burnt material demonstrated properties which went on to become the Portland cement industry.

Ironically, the development of these two materials, was more by accident than by design, since both materials demonstrate remarkable refractory characteristics.

Their development also defies natural laws of thermodynamics since they are generally impervious to heat and require massive inputs of thermal energy to create. The US cement industry in 1980 to produce 61.75 million tons of cement required 11 million tons of coal, 500,000 m3 of oil and 1.78 million m3 of natural gas, but required the mining and transport of a further 97 million tons of limestone, 9.6 million tons of clay or shale and 7.7 million tons of other products (Austin 1984). US clay and clay products statistics for the same year indicate 43.35 million tons of domestic clay use, and 2.9 million tons of exports for total values, including the combusted fuel component of $US1.061 X 109. Just as inefficiently, clay bricks are typically fired to temperatures between 875oC and 1200oC using predominantly fuel oil and natural gas. These two examples of gross energy inefficiency are mirrored and amplified throughout the construction industry as a result of inherited inefficiencies in the design and construction of the built environment, largely as a result of adherence to old or traditional designs, but also because excessive inputs (of steel, concrete, timber etc) are encouraged by the perceived risk of so-called under-sizing failure. .

Although traditionally designed homes appear to be favoured by the buying public, the architects in turn perpetuate the trend, by maintaining a suite of tried and tested designs. Whenever innovation is necessary in order to overcome a technical obstacle, the same architects overcome the obvious departure from tradition by adding, as necessary, facades by way of columns, quoins, decorative features to roof structures or walls, or in the extreme, return to a veneer of traditional stone.

Energy inefficiencies are amplified by virtue of:

• the weight of the materials customarily used for construction (sand, gravel, cement, bricks, steel mesh, roof tiles, timber); and hence
• fuel for freighting the several components to their ultimate destination;

but also in other ways:

• fuel used for travel to the site by the myriad of trades involved; and
• repetitive travel caused by lengthy and time consuming construction methods.

MFP Development Corporation propose to break the cycle of adherence to the old and energy inefficient by developing an example of world's best practice in innovative housing. Previous projects have tended to focus on post construction energy consumption (energy conservation issues) rather than the total of all energy inputs to construction per se.

Accordingly the on-going purpose of this project is to identify where major savings in energy can be found, with less emphasis on perceived market acceptability of design and to introduce to possibly reluctant builders, architects and other industry personnel, means to achieve energy savings in both the construction elements of the built form, and also the energy and time inefficient (and capital ineffective) methods of construction which have so permeated the industry. This latter aspect, once demonstrated, is likely to significantly influence the future direction of the urban development industry.

It is proper that an organisation such as MFP Development Corporation take a lead role in the development of such a paradigm shift in the provision of housing.

Categories for energy savings

1. Energy conservation

Reducing the energy consumption of the housing development by the following indicative measures:

• reducing energy demand
• using sustainable/renewable energy;
• optimising energy saving measures.
• These principally post construction issues have been addressed to varying extents elsewhere and it is not intended to provide detailed information here. Information on recommended energy conservation measures for the Mawson Lakes residential component are provided in a separate section.

2. Integral life cycle management

Examples include:

a. Reducing the energy capital of construction (also known as the embodied energy) by addressing the consumption of energy in the construction process . This category includes :

• finite elements such as clay bricks, which by their refractory nature require large amounts of energy to produce;
• cement used in concrete footings - cement requires very high inputs of energy to produce, again because the principal components display refractory characteristics (ie are insulators rather than conductors of heat);
• additional cement needed for concrete footings on expansive soils to compensate for the unnecessarily heavy conventional building structure;
• extra fuel used for repetitive vehicular access to the construction site as a result of lengthy or protracted building processes (compared to for example, the fuel required to deliver a modular home pre-assembled in a factory);
• fuel used in transport of raw material inputs to building materials such as bricks and concrete and including costs associated with freight of finished products to construction sites.

In general, the embodied energy includes the energy required in winning the raw material, manufacturing the product and transporting it to the site.

b. A closed circuit in materials use in order to prevent the exhaustion of natural resources and reduce environmental impact. This could include identifying end-uses for the recycling of construction materials, such as :

• recycled plastics for air ducts, service corridors, damp coursing etc.;
• crushed concrete to replace aggregate in specification tolerant aspects of the overall construction;
• possible use of steel & aluminium frames for roofs, windows and doors which whilst initially energy intensive construction elements, have very high participation rates in recycling programmes;
• use of service ducts for power cable etc in order to increase the recovery of copper and similar metals during demolition or renovation.

3. Quality improvement

Improving the quality, the surroundings, the construction materials and the indoor environment, and increasing the useful life of buildings. There is some inevitable overlap with energy conservation and life cycle issues in this category. These identified improvements can be achieved through a variety of innovations, such as:

• utilisation of passive solar energy through extra glass surface area in winter, spring and autumn;
• elimination of plastic and other materials which out-gas (eg PVC) - which has been linked to so-called `sick-building syndrome'.
• low energy content construction materials;
• solar hot water on north facing roofs coupled with geothermal heating and cooling systems for living areas;
• high efficiency insulation materials in roof and walling to preserve heat during winter and prevent heat entry during summer;
• west facing living areas adjacent to ventilated conservatory structure, with connecting sliding glass windows to act as buffer zone to external sun and hot air during hot summer and provide interface with nature;
• attention to sound insulation by location of sleeping areas away from roadways, utility rooms such as laundries and garages acting as buffers to minimise noise from external roads and double glazing of windows to sleeping areas where exposed to external noise.

Obstacles to progress

1. It is important to recognise that there will be difficulties associated with maintaining the emphasis on environmental innovation during the Mawson Lakes construction phase. The main dangers are:
2. the unsustainable levels of resource and energy exploitation which have characterised urban development in the past; and
3. the inefficiencies in construction of housing on a site-by-site basis;

   have now become regarded as normal.

   This mirrors similar concerns as the developing world struggles to achieve the same level of perceived quality of life, through exploitation of resources , but as a result of different economic pressures, needs to disregard environmental impact .

   The other challenges presented by Mawson Lakes reflect the difficulties in developing any new project, and include:

   • fear of losing the security of habit;
   • fear of criticism;
   • fear of disturbing tradition and making changes.

   Potential for export of Australian technologies

   1. One thing is clear - if we continue to adopt building methods and systems which we have come to accept as normal - and regard anything which strives to correct the imbalance of resource (including energy use) as too innovative (ie adopt a business as usual approach.); then the Australian home construction industry will fail to capitalise on the enormous growth potential for the housing markets in the developing world, and in particular our near northern neighbours such as Indonesia, Malaysia, Thailand and China.