Renovating Resources

A glossary to guide you through the terminology associated with building or renovating a sustainable home. Let us know through our Ask The Expert section if we’ve missed anything and we’ll add it.

Finding Your Way Through Terminology

Centre for Liveability Real Estate

Sustainability/Liveability Terms

If you’re passionate about your renovation or new home build delivering on health, efficiency and comfort then you’re likely to encounter a fair bit of terminology that you may not be familiar with. So, we’ve compiled a glossary to help you through the journey. If there are any words we’ve missed then let us know through our Ask the Expert section and we’ll add it to the list.

ABCB – NCCThe Australian Building Codes Board (ABCB) develops and administers the National Construction Code (NCC) through the Building Code of Australia (BCA).
abatementActivity that leads to a reduction in the level of greenhouse gas emissions.
AccuRateA house energy software (HERS) program used to simulate heating and cooling energy use in a home and produce a star rating acceptable under NatHERS. AccuRate is the national benchmark software tool developed by CSIRO based on decades of scientific research about the way buildings operate in Australian conditions.
air tightnessThe level of uncontrolled movement of air in to and out of a building
angle of incidenceThe angle that solar radiation strikes glass or walls. As the angle increases, the effective area of exposure to solar radiation reduces, more solar radiation is reflected, and less is transmitted
BASIX (Building Sustainability Index)Applies to all residential dwelling types in New South Wales and is part of the development application process.
BERS ProA house energy software (HERS) program similar to AccuRate used to simulate heating and cooling energy use in a home and produce a star rating acceptable under NatHERS.
biodiversityThe variety of all life, the different plants, animals and microorganisms, the genes they contain, and the ecosystems of which they form a part.
blackwaterWater that has been mixed with waste from the toilet.
Building Code of Australia (BCA)contains technical provisions for the design and construction of buildings in Australia. The BCA is Volumes One and Two of the National Construction Code (NCC). The BCA is produced and maintained by the Australian Building Codes Board (ABCB) on behalf of the Australian Government and state and territory governments.
building envelopeThe parts of a building’s walls, roof, ceilings and floors that separate artificially heated or cooled spaces from the exterior of the building or other spaces within the building that are not artificially heated or cooled.
carbon dioxide equivalent (CO2-e)A standard measure that takes account of the different global warming potentials of each greenhouse gas in a common unit.
carbon intensityA term used to indicate the amount of carbon released in the generation or use of energy. Up to three times more carbon is released in generating coal-fired electricity and transmitting it by using natural gas. We don’t generate natural gas but we release carbon when we use it. Renewable energy has no carbon emissions but some are emitted during manufacture of the generating equipment. This is usually paid back within a few years.
carbon neutral or carbon zeroBuildings that generate enough renewable energy on site to meet all their needs so that over a year the net amount of energy generated on site equals the net amount of energy required.
carbon positiveBuildings that generate more renewable energy than they consume so as to be net exporters. Carbon positive ratings can include only operational energy use, or can include both operational and embodied energy.
carbon offsettingA process that removes greenhouse gases or averts their emission into the atmosphere and destroys, stores or “sequesters” them for periods of varying duration. Carbon offsets are usually purchased by individuals or companies and used to cancel out or “offset” the emissions they generate during their normal course of business or day-to-day life.
carbon positiveBuildings that make a positive contribution by producing more renewable energy on site than the building requires and feeding it back into the grid.
carbon priceA financial cost imposed on individuals or organisations for causing the emission of greenhouse gases into the atmosphere. It could be a tax imposed by government, the outcome of an emissions trading market or a hybrid of taxes and permit prices.
climate changeA change to the climate that is attributed directly or indirectly to human activity that alters the composition of the global atmosphere and is additional to natural climate variability over comparable time periods
COP (coefficient of performance)A measure of appliance energy efficiency derived from dividing the energy output of an appliance by the energy input required to extract heating or cooling from external air, water or earth. The higher the COP, the more efficient the appliance.
conductionThe transfer of heat from one substance to another by direct contact.
conductive loss or gainLoss or gain of heat directly through contact with a person, object or building element.
construction systemsThe combination of materials used to build the main elements of a house – roof, floor and walls.
convectionHeat transfer in a gas or liquid by the circulation of currents driven by temperature differences.
convective air movementWarmer air rises because it is thinner and lighter while cooler air falls because it is denser and heavier. See stack ventilation.
coolthThe absence of warmth in thermal mass – dense materials that are good conductors. This ability is due to their ability to absorb a lot of warmth before heating up. Summer coolth storage is desirable in climates with low overnight summer temperatures to cool the mass.
cradle to cradleThe elimination of waste by recycling a material or product into a new or similar product at the end of its intended life, rather than disposing of it.
cradle to gateAn assessment of part of a products life cycle from resource extraction or manufacture (“cradle”) to the factory gate, i.e. before it is transported to the user or consumer. The use and disposal phases of the product are usually omitted.
cradle to graveThe lifecycle of a material or product that is not recycled or reused at the end of its life. See life cycle assessment.
dew pointThe temperature at which dew or condensation forms. This varies with humidity.
differential pricingA pricing method in which electricity has different prices based on the time of use. Also called “time of use”, “time-variant” or “flexible” pricing.
double-glazingSee insulating glass units (IGU).
earth couplingBuilding on or in the earth with conductive materials (e.g. concrete) that are not insulated from the earth. This couples the building to the thermal mass of the earth, which typically remains a constant temperature at a certain depth below grade, depending on the climate. Also known as “ground coupling” and “thermal coupling”.
EcospecifierAn international database ( developed in Australia detailing certified and verified sustainable products
embodied carbon or emissionsThe greenhouse gas emissions caused directly or indirectly from the production of embodied energy.
embodied energyThe energy used to extract, transport, manufacture and install a building material (see also cradle to cradle and cradle, gate or grave).
energy efficiencyThe ratio of the level of services or functions provided (e.g. heating, cooling or hot water) to the energy used to provide that output. Sometimes also used to describe the ability of the building envelope to reduce summer heat gain and winter heat loss.
energy management system (EMS)A computer system used in buildings to monitor, control and optimise their use of electricity.
Energy Rating LabelAn Australian scheme which assigns star ratings to a range of appliances. The star rating gives a comparative assessment of the appliance’s energy efficiency and the comparative energy consumption (usually kilowatt hours/year) estimates the annual energy consumption of the appliance. See Minimum Energy Performance Standard (MEPS).
evacuated tubeA glass tube which has had all air removed, often used in solar hot water systems.
expanded polystyrene (EPS)A rigid plastic foam insulation that provides high insulation values in addition to having strong structural integrity and having a closed cell structure that limits excessive moisture.
extenderA substance added to cement either to reduce cost or carbon emissions, or to some extent modify its properties.
FirstRateSoftware tool developed by the Victorian Government and used in rating the thermal performance of homes in Australia. FirstRate is accredited for use in NatHERS.
fixed appliances and equipmentAppliances, equipment and associated systems that are fixed in place within or on a building, have dedicated connections to the building’s energy or water supply and would normally not be moved from building to building on change of ownership or lease.
fly ashFine grey powder consisting mostly of spherical glassy particles that are produced as a by-product in coal-fired power stations or blast furnaces and used as extenders in concrete products.
Green StarA rating system developed by the Green Building Council of Australia to define best practice benchmarks in sustainability. Mostly applied to larger, commercial projects due to cost.
Green Tick®A symbol used to identify a product or service that has been independently certified as environmentally sustainable.
greenhouse gasesThe atmospheric gases responsible for causing global warming and climate change. The major greenhouse gases are carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs) and sulphur hexafluoride (SF6).
greenhouse intensityThe quantity of emissions produced directly or indirectly per unit of output.
GreenPowerA national accreditation program that sets environmental and reporting standards for renewable electricity products offered by energy suppliers to households.
greywaterWastewater from non-toilet plumbing fixtures such as showers, basins and taps.
grid (electricity)The network of wires, substations, transformers and switches that carry electricity from the generator to the consumer. The grid is designed to meet both normal “base load” demand and seasonal peak demand for residential, commercial and industrial purposes.
gross energy requirement (GER)A measure of the true embodied energy of materials, including extractions, transport, manufacturing and infrastructure.
heat exchangerOften referred to as a heat pump, these devices transfer heat from fluid or air on one side of a barrier to fluid or air on the other side without bringing them into direct contact, e.g. refrigerator, air-conditioner or heat pump HWS.
high mass constructionBuilding construction using masonry or other dense building materials that can absorb warmth or coolth to lessen the extremes of daily temperature fluctuations.
hydronic systemA system that circulates hot water or coolant through radiator panels in rooms, supplying a mix of convective and radiant heat; usually gas fired but can be heated by a wood fired heater, solar system or heat pump.
indigenous (plants)Original flora that occur naturally in an area; are adapted to the climate and form part of the local ecosystem.
indirect emissionsGreenhouse gas emissions generated elsewhere as a consequence of energy use in a building, e.g. emissions at electric power stations.
insulated glass unit (IGU) or double-glazingCombination of two or more glazing layers sealed with a gap between the layers.
inverterAn apparatus that converts direct current (DC) into alternating current (AC), e.g. used to convert photovoltaic array DC output to grid or standard appliance compatible AC current.
latent energy or heatThe energy absorbed by or released from a substance during a phase change from a gas to a liquid or a solid or vice versa.
life cycle assessment (LCA)The total environmental impact of a material or product through every step of its life from obtaining raw materials to manufacture, transport, storage, use, and disposal or recycling. Conducted to international standards using specialised software.
life cycle costing (LCC)A method of economic analysis that takes into account expected costs over the useful life of an asset.
Livable Cities IndexThis is international index produced by the Economist Intelligence Unit which judges the world most livable cities
Livable HousingThis refers to homes that have been designed to be accessible for ALL generations. The properties comply with the Silver, Gold or Platinum performance levels outlined in the Livable Housing Design Guidelines.
Liveability"Find or create your best home: healthy, efficient, comfortable and connected to your local community"
Liveability Property Features™These are property marketing features which offer the potential for reduced running costs and increased comfort if used correctly by the occupant.
Liveability Real Estate SpecialistThis is a new specialist real estate agent that are trained to identify sell and rent home with Liveability Property Features
LED (light emitting diode)A highly efficient form of lighting that illuminates through the movement of electrons in a semiconductor material instead of an incandescent filament.
low emissivity (low e) glassLow thermal emissivity (applied to glazing), i.e. transmits less heat.
low mass constructionSee lightweight construction.
low-emission energyEnergy that has been generated with significantly fewer emissions than average grid-supplied energy.
Minimum Energy Performance Standard (MEPS)A minimum efficiency standard that must be achieved by all appliances belonging to a particular group, e.g. refrigerators.
NatHERSThe Nationwide House Energy Rating Scheme, a framework that allows accredited computer software tools (Accurate, BERS and First Rate) to simulate and rate the thermal performance of the building envelope in 69 different climate zones
NatHERS starsThe rating system used to score the thermal comfort of a home, ranging from 0 to 10 stars where 0 stars gives practically no protection from hot or cold weather; 5 stars indicates a moderate level of thermal performance but still requires artificial heating and cooling and a 10 star home shouldn’t require any artificial heating or cooling.
north – true (solar) or magnetic (compass)True north is a fixed point of the earth’s surface that shows the sun’s true path in the sky. Magnetic north varies in position due to the movement of molten metal below the earth’s crust.
off-peak tariffA cheaper tariff offered by electricity providers to consumers who consent to having limits placed on when their water heaters or other devices can operate.
operational energyEnergy consumed to operate the building during its life.
orientationPositioning of a building in relation to seasonal variations in the sun’s path or to prevailing wind patterns
passive coolingDesign features that cool buildings without power consumption, e.g. cool breezes or cool nights.
passive designDesign that takes advantage of the climate to maintain a comfortable temperature range in the home. Passive heating and cooling is free.
passive heatingFeatures incorporated into a building’s design to use and maximise the effects of the sun’s natural heating capability.
peak demandThe maximum electricity demand in a given location over a given time, e.g. per day or over a season, often driven by cooling or heating loads due to temperature extremes.
photovoltaics (PV)Generate electricity by converting solar radiation into direct current electricity.
positive developmentDevelopment that has a net positive ecological and social impact.
process energy requirementThe energy used in the manufacture of a material.
radiationTransfer of heat to cooler object or person through contact, as contrasted with that transferred by conduction or convection.
renewable energyEnergy that is derived from sources that are renewed by natural processes or for all practical purposes cannot be depleted, e.g. solar energy, hydropower, wind, tide, geothermal and biomass.
R-valueA measure of resistance to the flow of heat through a given thickness of a material (as insulation) with higher numbers indicating better insulating properties.
smart applianceA product that uses electricity for its main power source which has the capability to receive, interpret and act on a signal received from a utility, third party energy service provider or home energy management device, and automatically adjust its operation depending on both the signal’s contents and settings from the consumer.
smart gridAn electrical grid that uses information and communications technology to gather and act on information, such as information about the behaviours of suppliers and consumers, in an automated fashion to improve the efficiency, reliability, economics and sustainability of the production and distribution of electricity.
smart homeAutomation of the home to provide improved convenience, comfort, energy efficiency and security; may include centralised control of lighting, heating, ventilation, air conditioning, appliances, security locks of gates and doors, and other systems.
smart meterAn electricity meter that records consumption in intervals of an hour or less and communicates that information at least daily back to the utility for monitoring and billing purposes. Smart meters enable two-way communication between the meter and the supplier.
solar accessThe amount of useful sunshine striking glass in the living spaces of a home.
solar cellAny device that directly converts the energy in light into electrical energy through the process of photovoltaics.
solar heat gain coefficient (SHGC)That fraction of incident solar radiation that actually enters a building through the entire window assembly (frame and glass) as heat gain.
split incentivesDescribe the situation in which the cost of implementing a sustainable measure is borne by the builder or developer whereas the benefits go to the consumer, e.g. where developers have little incentive to meet any additional cost of improving the energy efficiency of their buildings because the occupants gain the benefit of reduced energy bills with no gain for the developer.
stack ventilationThe upward movement of lighter, warmer air through high openings. Also known as convective air movement. Increased by negative pressure generated by the wind over the roof.
sustainable materialDoes not impact negatively on non-renewable resources, the natural environmental or human health.
temperature differential (ΔT)Heat flow through any building element (e.g. wall, floor, ceiling, window) is directly proportional to the temperature difference on either side of that element. This is called delta T (ΔT) or temperature differential. The greater the temperature differential, the greater the heat flow through the element.
thermal bridgingOccurs when a more conductive (or poorly insulating) material allows heat flow across a thermal barrier, e.g. steel frames.
thermal comfortA person’s subjective feeling of how comfortable the surrounding temperature is.
thermal lagThe amount of time taken for a material to absorb and then re-release heat, or for heat to be conducted through the material.
thermal massDense material able to absorb and store warmth and “coolth”; the “battery system” of passive design.
thermal performanceThe effectiveness of a building envelope in maintaining acceptable levels of thermal comfort in the building relative to the outside weather conditions by, minimising the need for artificial heating or cooling. In relation to a particular building material or element, the extent to which the material or element reduces or promotes heat loss or heat gain.
U-valueA measure of heat loss in a building element such as a wall, floor, roof or window, which demonstrates how well parts of a building transfer heat. The lower the U-value, the better the insulating ability. Expressed as Uw in windows. The inverse of R values, i.e. U=1/R, R =1/U
visible transmittanceIn window glass, the amount of visible light that is transmitted.
volatile organic compounds (VOC)Carbon containing chemicals that evaporate into the atmosphere at room temperature; identified as a potential health hazard.
WELS (Water Efficiency Labelling Scheme)Australia’s water efficiency labelling scheme, which requires certain products to be registered and labelled with their water efficiency in accordance with the standard set under the Commonwealth Water Efficiency Labelling and Standards Act 2005.
Window Energy Rating Scheme (WERS)A scheme that enables windows to be rated and labelled for their annual energy impact on a whole house, in any climate of Australia. To participate window makers must obtain energy ratings for their products from a rating organisation that is accredited by the Australian Fenestration Rating Council. WERS is managed by the Australian Window Association.
xeriscapeLandscaping designed to require minimal or no irrigation to maintain plants.
zero emissionApplies to buildings that use renewable energy sources on site to generate energy for their operation, so that over a year the net amount of energy generated on site equals the net amount of energy required by the building.


Centre for Liveability Real Estate

Centre for Liveability Real Estate

In addition to their expertise in residential real estate, The Centre for Liveability Real Estate also works collaboratively with the sustainable design, construction, manufacturing and assessment and industries in the development of information on this site.

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