Sharing Transparency for a More Efficient Future

Glossary of Building Rating Terms

Click a term to see its definition.

A | B | C | D | E | F | G | H | I | K | L | M | N | O | P | R | S | T | U | V | W | Z
G konstant

The constant in Newton’s law of gravitation relating gravity to the masses and separation of particles, equal to 6.67 × 10−11 N m2 kg−2. [Source: Oxford Dictionary]

Gain Utilization Factor

Factor reducing the total monthly or seasonal heat gains in the monthly or seasonal calculation method, to obtain the resulting reduction of the building energy need for heating. [Source: International ISO Standard 13790- Energy performance of buildings — Calculation of energy use for space heating and cooling (2008)]


The Global Buildings Performance Network (GBPN) is a globally organised and regionally focused network whose mission is to advance best practice policies that can significantly reduce energy consumption and associated CO2 emissions from buildings.


The sum of gross value added, at purchasers’ prices, by all resident and non-resident producers in the economy, plus any taxes and minus any subsidies not included in the value of the products in a country or a geographic region for a given period, normally one year. It is calculated without deducting for depreciation of fabricated assets or depletion and degradation of natural resources. [Source: IPCC - Annex I Glossary]


Giga Joule is a unit to measure energy use. [Source: ASHRAE]


GNP is a measure of national income. It measures value added from domestic and foreign sources claimed by residents. GNP comprises Gross Domestic Product plus net receipts of primary income from non-resident income.[Source: IPCC - Annex 1 Glossary]

Goal and Scope

The goal of an LCA study shall unambiguuously state the intended application, the reasons for carrying out the study and the intended audience, i.e. to whom the results of the study are intended to be communicated [ISO 40]. Goal definition is sometimes referred to as initiation (SPOLD, CAN). The scope of an LCA study shall consider and clearly describe [ISO 40]: 1) the functions of the product system, or, in the case of comparative studies, the systems; 2) the functional unit; 3) the product system to be studied; 4) the product system boundaries; 5) allocation procedures; 6) types of impact and methodology of impact assessment, and subsequent interpolation to be used; 7) data requirements; 8) assumptions; 9) limitations; 10) initial data quality requirements; 11) type of critical review, if any; and 12) type and format of the report required for the study. The scope should be sufficiently well defined to ensure that the breadth, the depth and the detail of the study are compatible and sufficient to address the stated goal. Because LCA is an iterative technique, the scope of the study may need to be modified while the study is being conducted, as additional information is collected. [Source: IEA Annex 31 Glossary]

Green Buildings

Green Buildings are those with increased energy efficiency, but at the same time reductions are made on water consumption, materials and assessment of the general impact on health and environment. Green buildings can include a long list of requirements including resources, indoor air quality and requirements that all products for the building must come from a local region. [Source: IEA (Laustsen J.) (2008) Energy Efficiency Requirements in Building Codes, Energy Efficiency Policies for New Buildings.]

Green Mark

Voluntary scheme which was launched in January 2005 by Singapore’s Building and Construction Authority as an initiative to drive Singapore’s construction industry towards more environmentally-friendly buildings. [Source: WGBC]

Green Star

A voluntary environmental rating system for buildings in Australia, launched in 2003 by the Green Building Council of Australia. [Source: WGBC]

Green Value

The net additional value obtainable by a green building in the market compared to conventional or non-green properties. [Source: Immovalue]

Greenhouse Effect

Greenhouse gases effectively absorb thermal infrared radiation, emitted by the Earth’s surface, by the atmosphere itself due to the same gases, and by clouds. Atmospheric radiation is emitted to all sides, including downward to the Earth’s surface. Thus, greenhouse gases trap heat within the surface-troposphere system. This is called the greenhouse effect. Thermal infrared radiation in the troposphere is strongly coupled to the temperature of the atmosphere at the altitude at which it is emitted. In the troposphere, the temperature generally decreases with height. Effectively, infrared radiation emitted to space originates from an altitude with a temperature of, on average, -19°C, in balance with the net incoming solar radiation, whereas the Earth’s surface is kept at a much higher temperature of, on average, 14°C. An increase in the concentration of greenhouse gases leads to an increased infrared opacity of the atmosphere and therefore to an effective radiation into space from a higher altitude at a lower temperature. This causes a radiative forcing that leads to an enhancement of the greenhouse effect, the so-called enhanced greenhouse effect. [Source: IPCC - Annex II Glossary Terms]

Greenhouse Gases

Greenhouse gases are those gaseous constituents of the atmosphere, both natural and anthropogenic, which absorb and emit radiation at specific wavelengths within the spectrum of thermal infrared radiation emitted by the Earth’s surface, by the atmosphere itself, and by clouds. This property causes the greenhouse effect. Water vapor (H2O), carbon dioxide (CO2), nitrous oxide (N2O), methane (CH4), and ozone (O3) are the primary greenhouse gases in the Earth’s atmosphere. Moreover, there are a number of entirely human-made greenhouse gases in the atmosphere, such as the halocarbons and other chlorine- and bromine-containing substances, dealt with under the Montreal Protocol. Besides CO2, N2O, and CH4, the Kyoto Protocol deals with the greenhouse gases sulfur hexafluoride (SF6), hydrofluorocarbons (HFCs), and perfluorocarbons(PFCs).

Gross Calorific Value

Quantity of heat released by a unit quantity of fuel, when it is burned completely with oxygen at a constant pressure equal to 101 320 Pa, and when the products of combustion are returned to ambient temperature. NOTE 1 This quantity includes the latent heat of condensation of any water vapour contained in the fuel and of the water vapour formed by the combustion of any hydrogen contained in the fuel. NOTE 2 According to ISO 13602-2, the gross calorific value is preferred to the net calorific value. NOTE 3 The net calorific value does not take account of the latent heat. [Source: EN 15603 Energy performance of buildings - Overall energy use and definition of energy ratings]

Gross Floor Area