Accredited energy assessor – a person registered with an accredited energy assessment scheme provider. The scheme provider will be licensed by the relevant government department to accredit competent persons in the energy assessment of buildings for the purpose of showing compliance with Building Regulations.

Approved software – Software approved by Communities and Local Government to produce EPCs and check compliance with Building Regulations.

BREEAM (British Research Establishment’s Environmental Assessment Method) – a method of assessing the sustainability of non domestic buildings.

BER (Building Emission Rate) – the estimated CO2 per m2 per year (kgCO2/m2/year. This is calculated in accordance with the NCM (National Calculation Method) and the SBEM.

CO2 index – the energy performance of a building is shown on the EPC as a Carbon Dioxide based index.

CSH (Code for Sustainable Homes) – an environmental assessment method for rating and certifying the performance of new homes. It aims to encourage continuous improvement in sustainable home building.

DER (Dwelling Emission Rate) – the estimated CO2 per m2 per year (kgCO2/m2/year) for the dwelling. It accounts for energy used in heating, fixed cooling, hot water and lighting.

DSM (Dynamic Simulation Model) – A software tool that models energy inputs and outputs for different types of building over time.

EPC (Energy performance certificate) – a certificate that confirms the energy rating of the building from A to G, where A is the most efficient and G is the least efficient, the better the rating the more energy efficient the building is.

FEE – Fabric energy efficiency – Energy demand for space heating and cooling expressed in kilowatt hours of energy demand per square meter per year (kWh/m2/year)

ISO 14001 – refers to a family of voluntary standards and guidance documents to help organizations address environmental issues. Included in the family are standards for Environmental Management Systems, environmental and EMS auditing, environmental labeling, performance evaluation and life-cycle assessment.

LCC (life cycle cost) analysis – A procurement evaluation technique which determines the total cost of acquisition, operation, maintenance and disposal of the building.

LZC (low or zero carbon) technology – A low or zero carbon source of energy generation.

MCS (Micro generation Certification Scheme) – an independent scheme that certifies microgeneration products and installers in accordance with consistent standards.

NCM – (National Calculation Methodology) – the methodology used for demonstrating compliance with the Energy Performance of Buildings Directive.

QA checking – once a BREEAM or CSH assessment is submitted by an assessor the BRE check them before issuing certificates.

RIBA stages – the definitive plan of work framework for the UK building design and construction process

SAP (Standard Assessment Procedure) – The approved methodology for rating the energy performance of dwellings.

SBEM (simplified Building Energy Model) – is a computer program that provides an analysis of a building’s energy consumption.

SQA (Suitably qualified acoustician) – organisations or individuals having UKAS accreditation. The SQA can be used to provide advice and testing to achieve a umber of BREEAM/CSH credits.

SQE (Suitably qualified ecologist) – an ecologist who holds a degree in a relevant subject, is a practising ecologist (with a minimum of 3 out of the last 5 years relevant experience) and is covered by a professional code of conduct and is subject to a peer review. The ecologist cabn be used to report and provide advice that will allow a number of BREEAM/CSH credits to be awarded.

TER (Target Emission Rate) – is the maximum allowable CO2 per m2 per year (kgCO2/m2/year) arising from energy used in heating, cooling, hot water and lighting which would demonstrate compliance with Part L.

Decibel (dB) – The dB (decibel) is the logarithmic unit used to describe sound (or noise) levels. The human ear can detect a wide range of pressure variations; a logarithmic scale is therefore necessary to convert the values into manageable numbers.

Frequency (Hz) – Frequency (described as ‘pitch’ in a musical context) is a measure of the rate of fluctuation of a sound wave. The unit used is cycles per second, or hertz (Hz). Sometimes large frequency values are written as kilohertz (kHz), where 1 kHz = 1000 Hz. Young people with normal hearing can hear frequencies in the range 20 Hz to 20,000 Hz. However, the upper frequency limit gradually reduces as a person gets older. The spectral content of sound is generally analysed by grouping frequencies in bands, either octave or 1/3 octave bands.

A-Weighting – The human ear is less sensitive to the low and very high ends of the frequency spectrum. An ‘A-weighted’ measurement has a spectral correction term applied to take into account the sensitivity of the human ear at different frequencies. A-weighted sound levels are normally written dB(A) or dBA.

Leq – This is the ‘equivalent continuous noise level’. It is an average of the total sound energy measured over a specified time period. In other words, Leq is the level of a continuous noise which has the same total energy as the real fluctuating noise, measured over the same time period. It is increasingly being used as the preferred parameter for all forms of environmental noise.

LAeq – This is the A-weighted ‘equivalent continuous noise level’.

LA90 – Typically used as an indication of background noise levels, LA90 is the A-weighted sound level which is exceeded for 90% of the measurement period.

Indoor Ambient Noise Level – This typically refers to the ambient noise within a space as a result of intrusion of external noise sources, e.g. traffic, and internally generated building services noise. Noise from occupants and equipment, e.g. computers, printers etc. is normally excluded.

Noise Rating (NR) curves – Noise Rating curves are commonly used to define building services noise. They are a series of curves, each curve having a defined value at each octave band.

Free-field level – Sound pressure level measured outside, far away from reflecting surfaces and free from obstructions.

Façade level – Sound pressure level measured 1 m to 2 m in front of a façade. Façade measurements are usually 2-3dB higher than corresponding free-field measurements.

Sound Insulation Testing – Sound insulation testing refers to the method of measuring and quantifying the level of sound insulation achieved between two spaces (i.e. the wall/floor structures that separate dwellings).

Airborne Sound Insulation testing – An airborne sound insulation test measures the ability of a wall or floor partition to resist airborne sound. The process involves generating noise via a loudspeaker in the ‘source’ room and taking measurements in the both the ‘source’ and ‘receive’ room to determine the difference in sound level between the two rooms. Airborne sound insulation is typically measured using the parameter ‘Dnt,w’ or ‘Dnt,w + Ctr’.

Impact Test – An impact sound insulation test measures a floor structure’s ability to resist structure-borne sound (e.g. people walking on the floor). The process involves positioning a calibrated tapping machine on the source room floor and measuring sound levels in the receive room below. Impact sound insulation is typically measured using the parameter L’nT,w.

Reverberation time (T or RT) – The time required for the sound level in a room to decrease by 60dB after the sound source has stopped. Since the reverberation time in a space usually varies with frequency, T can be expressed in terms of the average value across a frequency range.

Mid-frequency reverberation time (Tmf) – Tmf typically refers to the arithmetic average of the reverberation time in the 500 Hz, 1 kHz, and 2 kHz octave bands.

Flanking Sound Transmission – This refers to any sound transmission which occurs via indirect paths i.e. any path other than directly through the separating wall/floor under test.

D (level difference) – The difference in sound levels in dB between the source and receiving room.

DnT (standardised level difference) – The difference in sound levels in dB between the source and receiving room, standardised to a reference reverberation time.

Dw (weighted level difference) – The level difference is typically measured in 1/3 octave bands between 100 Hz and 3.15 kHz, and reduced to a single number quantity, known as the weighted level difference.

DnT,w (weighted standardised level difference) – The standardised level difference is typically measured in 1/3 octave bands between 100 Hz and 3.15 kHz, and reduced to a single number quantity, known as the weighted standardised level difference.

DnTw + Ctr (standardized level difference + spectral adaptation term) – Similar to DnT,w but with a spectral adaptation term ‘Ctr’ applied. The Ctr correction gives more importance to low frequency sounds.

Rw (weighted sound reduction index) – Rw is a single number quantity that describes the sound reduction properties of a specific material component, measured under controlled laboratory conditions.

L’nT,w (weighted standardized impact sound pressure level) – The single number quantity used to characterize the impact sound insulation of floors over a range of frequencies, standardised to a reference reverberation time.

LAr,Tr (rating level) – Commonly used for rating industrial noise, this is the equivalent continuous A-weighted sound pressure level for a given time period, plus any adjustment to take account of the impulsive or tonal characteristics of the noise.

Sound Absorption Class – Designated A-E, where materials rated at sound absorption Class A provide the highest levels of sound absorption, gives a general indication of the absorption characteristics of a material.

Building Regulations Approved Document E – This deals primarily with the sound insulation properties of residential developments. Section E1 sets out minimum airborne and impact sound insulation standards between dwellings and rooms for residential purposes. Section E2 covers internal walls and floors within dwellings. Section E3 deals with the control of reverberation within common internal parts of buildings containing flats or rooms for residential purposes and section E4 relates to acoustics within new school buildings.

Building Bulletin 93 (BB93) – This sets out the acoustic design criteria for new schools, covering indoor ambient noise levels in unoccupied spaces, sound insulation between spaces and control of reverberation. BB93 has now been superseded by the document ‘Acoustic Performance Standards for the Priority Schools Building Programme’ for schools falling under this scheme.

NHS Technical Design Manual 4032 v 0.6: England – This is the most recent guidance concerning acoustics within healthcare premises, superseding HTM 08-01. As with BB93, the document covers indoor ambient noise levels in unoccupied spaces, sound insulation between spaces and control of reverberation.

BS4142:1997 – This document describes the method for assessing the potential impact of industrial noise sources on nearby existing noise sensitive premises.

BS8233:1999 – This gives recommendations for the control of noise in and around buildings, and suggests appropriate criteria and limits for different situations.

PPG24 – Planning Policy Guidance 24 (PPG24) guides local authorities in England on the use of their planning powers to minimise the adverse impact of noise. This guidance has recently been cancelled following the publication of the National Planning Policy Framework (2012), however, due to a lack of updated technical guidance, PPG24 is still often used as the basis for noise assessments.

Accredited energy assessor – a person registered with an accredited energy assessment scheme provider. The scheme provider will be licensed by the relevant government department to accredit competent persons in the energy assessment of buildings for the purpose of showing compliance with Building Regulations.

Approved software – Software approved by Communities and Local Government to produce EPCs and check compliance with Building Regulations.

BREEAM (British Research Establishment’s Environmental Assessment Method) – a method of assessing the sustainability of non domestic buildings.

BER (Building Emission Rate) – the estimated CO2 per m2 per year (kgCO2/m2/year. This is calculated in accordance with the NCM (National Calculation Method) and the SBEM.

CO2 index – the energy performance of a building is shown on the EPC as a Carbon Dioxide based index.

CSH (Code for Sustainable Homes) – an environmental assessment method for rating and certifying the performance of new homes. It aims to encourage continuous improvement in sustainable home building.

DER (Dwelling Emission Rate) – the estimated CO2 per m2 per year (kgCO2/m2/year) for the dwelling. It accounts for energy used in heating, fixed cooling, hot water and lighting.

DSM (Dynamic Simulation Model) – A software tool that models energy inputs and outputs for different types of building over time.

EPC (Energy performance certificate) – a certificate that confirms the energy rating of the building from A to G, where A is the most efficient and G is the least efficient, the better the rating the more energy efficient the building is.

FEE – Fabric energy efficiency – Energy demand for space heating and cooling expressed in kilowatt hours of energy demand per square meter per year (kWh/m2/year)

ISO 14001 – refers to a family of voluntary standards and guidance documents to help organizations address environmental issues. Included in the family are standards for Environmental Management Systems, environmental and EMS auditing, environmental labeling, performance evaluation and life-cycle assessment.

LCC (life cycle cost) analysis – A procurement evaluation technique which determines the total cost of acquisition, operation, maintenance and disposal of the building.

LZC (low or zero carbon) technology – A low or zero carbon source of energy generation.

MCS (Micro generation Certification Scheme) – an independent scheme that certifies microgeneration products and installers in accordance with consistent standards.

NCM – (National Calculation Methodology) – the methodology used for demonstrating compliance with the Energy Performance of Buildings Directive.

QA checking – once a BREEAM or CSH assessment is submitted by an assessor the BRE check them before issuing certificates.

RIBA stages – the definitive plan of work framework for the UK building design and construction process

SAP (Standard Assessment Procedure) – The approved methodology for rating the energy performance of dwellings.

SBEM (simplified Building Energy Model) – is a computer program that provides an analysis of a building’s energy consumption.

SQA (Suitably qualified acoustician) – organisations or individuals having UKAS accreditation. The SQA can be used to provide advice and testing to achieve a umber of BREEAM/CSH credits.

SQE (Suitably qualified ecologist) – an ecologist who holds a degree in a relevant subject, is a practising ecologist (with a minimum of 3 out of the last 5 years relevant experience) and is covered by a professional code of conduct and is subject to a peer review. The ecologist cabn be used to report and provide advice that will allow a number of BREEAM/CSH credits to be awarded.

TER (Target Emission Rate) – is the maximum allowable CO2 per m2 per year (kgCO2/m2/year) arising from energy used in heating, cooling, hot water and lighting which would demonstrate compliance with Part L.

Air tightness / air permeability / air leakage – defined as the resistance of the building envelope to inward or outward air permeation. Air leakage is driven by pressure differentials between inside and outside a building caused by the wind, stack effect and mechanical ventilation systems.

Air barrier or air seal line – the physical components that make up the airtight envelope of the building. The air barrier needs to be continuous around the whole envelope – roof, walls and ground floors – and needs to be durable and maintainable in the long term. The air seal line can be drawn on construction drawings.

Air test or air leakage pressure test – the building is pressure tested by connecting a fan and measuring the airflow rates required to keep the building at various positive pressures.

Air permeability – expressed as the amount of air leakage in cubic metres, per hour, per square metre of envelope at a nominal pressure differential of 50 Pascals, between inside and outside the building envelope.

Q50 – air flow rate required to pressurise the building envelope to 50 Pascals, the measured unit of which is cubic metres per second.

Air tightness / air permeability / air leakage – defined as the resistance of the building envelope to inward or outward air permeation. Air leakage is driven by pressure differentials between inside and outside a building caused by the wind, stack effect and mechanical ventilation systems.

Air barrier or air seal line – the physical components that make up the airtight envelope of the building. The air barrier needs to be continuous around the whole envelope – roof, walls and ground floors – and needs to be durable and maintainable in the long term. The air seal line can be drawn on construction drawings.

Air test or air leakage pressure test – the building is pressure tested by connecting a fan and measuring the airflow rates required to keep the building at various positive pressures.

Air permeability – expressed as the amount of air leakage in cubic metres, per hour, per square metre of envelope at a nominal pressure differential of 50 Pascals, between inside and outside the building envelope.

Q50 – air flow rate required to pressurise the building envelope to 50 Pascals, the measured unit of which is cubic metres per second.