BuildingRating

Sharing Transparency for a More Efficient Future

Glossary of Building Rating Terms

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R-Value

The reciprocal of the time rate of heat flow through a unit area induced by a unit temperature difference between two defined surfaces of material or construction under steady-state conditions. Units of thermal resistance are h·ft[sup]2[/sup]·°F/Btu (m[sup]2[/sup]·°K/W.) Thermal resistance is the reciprocal of the thermal conductance. [Source: ASHRAE]

Rating

Rating refers to an energy performance assessment structure (rating system), the associated evaluation methodology (rating tool), its use (as a verb), and the final result (rating score). [Source: Perez-Lombard].

Rating and Disclosure

Rating and disclosure refers to the practice of evaluating the relative energy efficiency of a home or building and making this information known to consumers. The mechanism aims to raise consumer awareness about energy performance of and encourage building energy improvements through greater market transparency. [Source: Institute for Market Transformation]

Rebound Effect

The concept that some or all of the expected energy savings from energy efficiency improvements do not occur because of increasing demand for energy and other services. [Source: IEA Report - Spreading the Net, 2012.]

Recoverable System Thermal Loss

Part of a system thermal loss which can be recovered to lower either the energy need for heating or cooling or the energy use of the heating or cooling system. NOTE This depends on the calculation approach chosen to calculate the recovered gains and losses (holistic or simplified approach). [Source: International ISO Standard 13790- Energy performance of buildings — Calculation of energy use for space heating and cooling (2008).]

Recovered System Thermal Loss

Part of the recoverable system thermal loss which has been recovered to lower either the energy need for heating or cooling or the energy use of the heating or cooling system NOTE This depends on the calculation approach chosen to calculate the recovered gains and losses (holistic or simplified approach). [Source: International ISO Standard 13790- Energy performance of buildings — Calculation of energy use for space heating and cooling (2008).]

Reference Building

A hypothetical building design often used in asset rating calculations as a baseline for comparison. Reference buildings share the general location and dimensional aspects with the actual building being rated, as well as calculation methods, but use default values for certain key inputs.

Regulatory and Institutional Risks

Regulatory and institutional risks refer to uncertainty on the reliability of policies in place or unpredictable, sudden changes in regulation. [Source: IEA (2010) Money Matters]

Relative Energy Saving Target

This target is set based on a percentage reduction of the total energy used. The energy consumption after renovation as well as savings will therefore depend on the consumption of the building before the renovation. Targets should be given in percent. [Source: GBPN, 2012]

Residential Buildings

A building should be regarded as a residential building when more than hald of the floor area is used for dwelling purposes. Other buildings should be regarded as non-residential. Two types of residential buildings can be distinguished: 1.) Houses (ground-oriented residential buildings): comprising all types of houses (detached, semi-detached, terraced houses, houses built in a row, etc.) each dwelling of which has its own entrance directly from the ground surface; 2.) other residential buildings: comprising all residential buildings other than ground-oriented residential buildings as defined above. [Source: OECD Glossary of Statistical Terms]

Retail Energy Sales Company

Retail energy sales company means a natural or legal person who sells energy to final customers. [Source: EU Directive 2012/27/EU on Energy Efficiency]

Retrocommissioning

Retrocommissioning is a systematic process for identifying and implementing operational and maintenance improvements in a building and ensuring continued performance over time. Retrocommissioning intends to optimize the operation and maintenance of building subsystems as well as how the systems function together. The RCx process focuses on O&M improvements and diagnostic testing rather than capital improvements (although some needed capital improvements may be recommended as a result). [Source: ACEEE Glossary]