High Performing Buildings - Fall 2010 - (Page 64)

NABERS (the National Australian Built Environment Rating System) is a performance-based rating system for existing buildings. NABERS rates a commercial office, hotel or retail building on the basis of its measured operational impacts on the environment. the rating accounts for 12 continuous months of electricity and gas bills, plus any other energy sources consumed (for example, diesel fuel used by standby generators). As the primary purpose of NABERS Energy is to reduce GHG emissions related to office building operation, each energy source is converted to GHG emissions using common conversion factors. Electricity in Australia is predominantly coal based, resulting in a high carbon intensity of about 1 kg CO2/kWh (2.2 lb CO2/kWh). The method of carbon accounting that has evolved in Australia relies on state-based averages of carbon intensity in electricity. These averages vary each year, depending on the primary fuel mix. To eliminate this annual variance and to allow comparison of benchmarks across the market and through the years, carbon intensity factors have been fixed in NABERS. This also reflects that the primary source of energy is somewhat outside the control of the building owners or occupants. in this application, GHG intensity acts as a proxy for primary energy. While on-site gas generation likely results in a higher energy use intensity, the application of GHG factors credits the lower emissions of gas generation, particularly when used in a cogeneration or trigeneration system, in contrast to grid electricity. in practice, other energy forms can enter a building, such as hot or chilled water from an adjacent facility. Each of these forms of energy must be accounted for in the rating and measured with similar accuracy as electricity and gas. A building may use energy in a way that is outside the scope of a typical office building (for example, gas that is consumed in a commercial kitchen for a public cafeteria within the building). This non-office energy can be deducted from the total energy only if it is metered effectively, and if reliable meter readings are available for the same annual period being measured. renewable Energy On-site renewable energy generation is automatically taken into account by measuring only energy imported into the site. Building owners can choose to purchase Greenpower, a zero carbon source of electricity delivered under a national accreditation program (www.greenpower.gov.au). P E r c E N ta G E O f a u s t r a l i a N O f f i c E M a r k E t N a B E r s r at E d N a B E r s r at i N G s PEr calENdar yEar source: new south Wales department of environment, Climate Change and Water 64 HigH Performing Buildings fa l l 2 0 1 0 http://www.greenpower.gov.au

Table of Contents for the Digital Edition of High Performing Buildings - Fall 2010

High Performing Buildings - Fall 2010
Table of Contents
IDeAs Z2 Design Facility
Lighting Design Alliance
Manassas Park Elementary School and Prekindergarten
FC Gulf Freeway Office Building
Capturing Condensate
National Australian Built Environment Rating System
Tyson Living Learning Center

High Performing Buildings - Fall 2010