Buildings and Other Structures

Design and construction of buildings to conform with environmental principles is becoming more widespread. Already a number of local Councils throughout Australian have adopted the Nationwide House Energy Rating Scheme (NatHERS) which involves a computer simulation of the energy-efficiency of buildings. Development applications that fail to meet a specified efficiency level may be rejected. In the future this process will become more common.

Building, renovating or extending structures anywhere can be carried out so that environmentally-friendly features are implemented. However, areas near bushland present a number of challenges not faced by those living in totally urbanized areas.

Development in the Mountains

Control of most aspects of development is controlled by Blue Mountains City Council through the Development Application system. When considering a proposed new development or an extension to an existing development, Council will consider the ways in which the proposal will affect vegetation, animals, water pollution through effluent disposal. In sensitive areas a Flora and Fauna Study may be required prior to approval.

Energy Efficiency

Creating and maintaining an energy efficient building is probably the most effective way that the average person can contribute to environmental protection. Of course, there is also the added advantage that improved energy efficiency often results in a lower overall power cost despite the "up front" costs that might be involved. Some of the most important points to consider are:

Correct orientation of new buildings to make efficient use of sunlight for lighting and heating.

Ceiling insulation to reduce heat loss in winter and heat entry in summer.

Skylights to allow natural light to reach dark areas.

Solar heating when upgrading water heating facilities.

Minimizing the use of air conditioners and considering roof cavity fans as an alternative (these use low-power fans to extract and expel hot air to the atmosphere).

Maintaining effective seals on refrigerators, freezers and ovens.

Minimizing hot water usage which accounts for about 35% of home energy usage.

Minimizing the use of room heaters (which account for about 24% of home energy usage) and wearing warmer clothing as an alternative, if practical.

Choosing energy efficient appliances - take note of the "Energy Rating" labels (the more stars the better!).

Well located clerestory windows are superior to skylights for energy efficiency and light.

Consulting the Architect

If you are keen to build an energy-efficient building and intend using an architect, it’s important that your architect understands and is sympathetic to what you are trying to achieve. It may be worthwhile developing a written list of environmental design principles that you expect the architect to apply. These could include:

Siting of the building to minimize excavation and to avoid future runoff problems that might direct garden drainage into bushland.

Orientation of the building to make best use of natural light internally and to maximize the efficiency of solar heating collectors.

Selection of building materials which are environment-friendly.

Retaining as much as possible of existing native vegetation.

Using physical barriers for termite protection rather than chemicals ...see Chemicals and Pest Control.

Home Energy Efficiency

Integral Energy - Customer Services

Cnr Henry & Station Sts, Penrith, 2749

02-9833-6753

www.integral.com.au/

Advice available includes a free Home Energy Management Scheme (HEMS) which aims to identify where energy is being used in the home and to suggest ways of reducing energy use.

Environment-friendly Building Materials

All building construction has some environmental impacts. These include the impacts of extraction of raw materials, impacts in processing and manufacture (energy use and emissions), transportation impacts and construction techniques. When choosing building materials it is desirable to consider the overall impacts of particular products and of the proposed construction methods and select those with the best overall environmental benefit.

One method of comparing materials is on the basis of the Process Energy Requirement (PER) which is a measure of the energy used in manufacture (megajoules per kilogram). The PER for some common building materials is shown in the table on below. However, other factors need to be considered as well....these include environmental impact, reusability and recyclability of the chosen materials (also shown in the table).

Environment-friendly Building Materials

EcoDesign Foundation

PO Box 369, Rozelle, 2039

Fax: 02-9555-9564

www.edf.edu.au

Process Energy Requirements (PER) for some common building materials

Impacts of Construction

Soil erosion from building sites can release large quantities of sediment to waterways. The NSW Environmental Protection Authority estimates that up to four truckloads of soil can be lost from a single building site during one storm.

Sediment Control

Sediment pollution can be minimized in several ways:

Divert clean runoff around disturbed construction areas so that it doesn’t "pick-up" sediment.

Minimize the disturbance of vegetated areas and other site disturbance.

Restrict vehicles to a single entry and exit.

Ensure stockpiled material (e.g. sand, soil and gravel) cannot be washed into drainage channels by rain.

Provide sediment filters (special "silt fences" or hay bales).

Protecting Existing Vegetation

Having designed a house so that specific trees and shrubs are to be retained, ensure that the builder is not only aware of these but that they are clearly roped off. Many different sub-contractors can be involved in a construction project and they may not all be aware of your discussions with the builder.

Water Supply

Reticulated water is available to most developed areas in the Blue Mountains. Even so, the installation of rainwater tanks may be worth considering to reduce the dependence on the reticulated supply (and its cost!). Blue Mountains Council will normally approve a water tank subject to an appropriate size being chosen which is consistent with the proposed location, adequacy of overflow provision, and relationship to neighbours..

The cost of rainwater tanks varies from about $250 for 500 litre capacity to about $2000 for 22,500 litre capacity. For use as a back-up supply to a reticulated water system, the capacity of the tank required is not critical but the larger the better. Selection will depend on factors such as the roof area available to collect water, the planned usage of the water and the space available to install the tank.

Grey Water

The use of "grey water" for lawn and garden watering is also worth considering. Grey water is the waste from laundries, kitchens and showers, but not toilets. The volume of grey water produced from a household can be over 200,000 litres per year. To ensure that such use is environmentally acceptable it is necessary to obtain prior approval from Blue Mountains City Council.

Irrigation of grey water from washing machines is probably the easiest to implement and can be done relatively easily by fitting a diversion valve to the laundry tub outlet. This can then be connected to a hose to redirect water to the garden area.

Grey water may have a high concentration of nutrients (particularly phosphorus) so it’s important that it not be allowed to overflow to bushland areas. High phosphorus levels can also kill certain garden plants such as proteas, banksias and grevilleas.

Wastewater

Most urban areas of the Blue Mountains are connected to a reticulated sewerage system or are to be connected in the near future. In unsewered areas, the disposal method must be approved by Blue Mountains City Council and will depend on specific site conditions. Some options include:

• Septic tank - feasible only where soils are porous enough to absorb the tank outflow or where "pump out" facilities are available
• Composting toilet - waterless systems which store wastes in a composting container and promote decomposition by circulating air. They can be either "continuous" or "batch" processes. The former uses a single composting tank while, in the latter, a full tank is replaced by a spare tank. Well designed composting toilets are a far cry from the "bush loo"! They also save a considerable volume of water....as much as 15-20,000 litres per year for a family of three. Their environmental benefit depends on disposal of the compost in a way that does not cause pollution.
• Biological Aerated Systems - mini sewage treatment systems which irrigate the treated waste on the grass and garden of the property. They can be very effective but maintenance requirements are high and urban lots are usually not large enough to absorb the outflow. Council requires a minimum irrigable area of 4,000 sq.m for these units.

Note: Blue Mountains City Council should be contacted for current information by householders seeking to make any decisions concerning ‘Septic Tanks’, ‘Composting Toilets’ or biological Aerated Systems.

Water and Sewage Leaks

Leaking domestic water supplies can prove to be expensive if ignored but leaking water mains or street hydrants and valves can waste large amounts of water in a surprisingly short time. A plumber must be called to attend to water leaks on private property and please notify Sydney Water if you notice leaks elsewhere.

The effluent from septic tanks is highly polluting and is a health hazard, particularly to children. Leaking or faulty septic systems can also cause serious damage to waterways or to bushland. Please advise Council if any leaks or illegal discharges are noticed (e.g. septic effluent being diverted to street gutters or stormwater drains).

Regulations were introduced in 1998 which will require on-site sewage management systems to be licensed by June 1999. The Regulation provides for a licence fee and system inspections.