Building compliance glossary
Plain definitions of the terms used across this site.
Reading the building compliance glossary
Project drawings and assessment reports often use short technical terms with quite specific meanings. This glossary explains the language used across our services in England. Follow each linked entry to the service or guide that owns the subject, particularly where similar terms describe different types of evidence.
Use these definitions when preparing a brief or comparing requested documents. They describe concepts rather than deciding which assessment your building needs. A useful enquiry includes the original request, the building use and the design stage, so an assessor can distinguish a calculation input from a site measurement or a completed report.
Building compliance glossary terms
A
- Acoustic design
- The development of building details and specifications to manage sound. It can address separating constructions, internal conditions and noise from services.
- Air permeability
- A measure of air leakage through a building envelope under a stated test pressure. Results need interpreting against the project's agreed assessment basis.
- Air tightness test
- A site test that uses pressure differences to measure leakage through the building envelope. Preparation includes checking openings, penetrations and the agreed test boundary.
- Airborne sound
- Sound travelling through air before reaching another space through a separating construction or another path. Speech and music are common examples.
- As-built assessment
- An assessment reflecting the building as completed rather than only its original design. Substitutions and installation evidence help establish accurate inputs.
- Asbestos register
- A record of identified or presumed asbestos-containing materials and their locations. Survey findings help inform the information recorded for building management.
- Asbestos survey
- An investigation scoped to identify asbestos-containing materials within specified areas. The purpose and access arrangements determine the type of survey commissioned.
- Automatic opening vent
- An opening device used as part of a smoke ventilation arrangement. Its controls and operation need considering alongside the wider system.
B
- Background noise
- The underlying sound environment against which a particular source may be considered. Representative conditions matter more than an isolated convenient observation.
- Background ventilation
- Ventilation provided through purpose-made openings to support air exchange within rooms. Opening size and product performance inform the design assessment.
- Borescope inspection
- A visual investigation using a small camera to examine otherwise concealed spaces. Findings relate to accessible views rather than every hidden surface.
- BRUKL report
- An output from a non-domestic energy compliance model showing assessment inputs and results. Its revision should correspond with the building specification being assessed.
- Building envelope
- The parts of a building separating its internal environment from outside or other relevant spaces. The assessment boundary should be agreed before testing.
C
- Cold bridge
- An everyday term for a thermal bridge where local heat flow differs from surrounding construction. Junction geometry and material changes influence its effect.
- Commissioning
- The process of setting up and checking an installed system against its intended operation. Recorded settings help explain the condition in which it was assessed.
- Condensation risk
- The possibility of moisture condensing on surfaces or within a construction. Assessment considers the proposed layers and relevant environmental assumptions.
D
- DEC
- Short for Display Energy Certificate, which describes operational energy performance using consumption information. Its evidence base differs from a calculated asset rating.
- Design-stage assessment
- An assessment based on proposed drawings and specifications before construction is complete. It helps teams compare options while changes remain practical.
- Dwelling emission rate
- A modelled carbon emissions indicator for a dwelling's assessed energy uses. Its value depends on the specification and assumptions entered into the calculation.
E
- Energy statement
- A project document explaining the proposed approach to energy performance. Planning requirements differ by council, so the scope should follow the local brief.
- Environmental noise
- Sound in the external environment affecting a site or surrounding receivers. A survey brief identifies relevant sources, operating conditions and assessment locations.
- EPC
- Short for Energy Performance Certificate, presenting calculated energy performance and related information about a property. It serves a different purpose from a site test report.
- Equivalent area
- A way of expressing the airflow performance of a ventilation opening. Product data helps distinguish ventilation performance from the opening's physical dimensions.
- Extract ventilation
- Ventilation that removes air from an internal space, often from rooms producing moisture or odours. Installed airflow can be measured at relevant terminals.
F
- Fabric heat loss
- Heat transfer through building elements such as walls, roofs, floors and windows. Energy calculations consider these elements alongside other sources of heat loss.
- Fire risk assessment
- An assessment of fire hazards, people at risk and relevant precautions. Its scope depends on the premises and the information available to the assessor.
- Flanking transmission
- Sound transmission along paths around the main separating construction. Junctions and adjoining elements can influence performance even where the separating element is well specified.
- Flow rate
- The quantity of air or water passing a point over time. The relevant measurement and units depend on the service being assessed.
G
- Glazing ratio
- The relationship between glazed area and a stated reference area. Window size and orientation can affect both energy performance and summer comfort.
H
- Heat recovery
- The transfer of heat from outgoing air to incoming air through suitable equipment. Actual system performance also depends on installation, settings and maintenance.
- Home Energy Model
- A government building energy modelling methodology described through the Home Energy Model guidance. Project advice should distinguish published methodology information from assumptions about its application.
I
- Impact sound
- Sound generated by physical contact with a construction, such as footsteps on a floor. Floor build-ups and junction details influence transmission to adjoining spaces.
- Infiltration
- Uncontrolled air movement through gaps in the building envelope. It differs from deliberate ventilation openings designed to provide managed air exchange.
- Interstitial condensation
- Condensation occurring within a construction rather than on its exposed surface. Layer arrangement and moisture behaviour affect the assessed risk.
L
- Legionella risk assessment
- An assessment of water systems and conditions that could support exposure to legionella bacteria. System details, occupancy and management information help define the investigation.
M
- Management asbestos survey
- A survey intended to support the management of asbestos during normal occupation and foreseeable maintenance. HSE survey guidance explains how its purpose differs from refurbishment investigations.
- Mechanical ventilation
- Ventilation driven by fans rather than relying solely on natural forces. Assessment considers the system arrangement and the intended supply or extract duties.
- MVHR
- Mechanical ventilation with heat recovery supplies and extracts air while transferring heat between air streams. Commissioning checks the installed arrangement and settings.
N
- Noise impact assessment
- An assessment explaining how sound from a source may affect relevant receivers. The scope connects survey evidence, operating assumptions and any proposed mitigation.
- Noise-sensitive receiver
- A location or use where noise effects need consideration, such as a bedroom. Relevant receivers depend on the source and assessment question.
O
- Overheating assessment
- An assessment of the risk of excessive indoor temperatures under stated conditions. Glazing, shading, occupancy assumptions and ventilation options influence the findings.
P
- Party floor
- A floor separating different premises, often between flats. Acoustic design considers the floor structure, ceiling treatment, finishes and adjoining transmission paths together.
- Party wall
- A wall separating adjoining premises. For acoustic work, the wall construction and its junctions are considered together rather than as an isolated layer.
- Plant noise
- Sound produced by building equipment such as fans, condensers or pumps. Assessment considers equipment data, location, operation and the surrounding sound environment.
- Pre-purchase asbestos survey
- An asbestos investigation commissioned to inform a property purchase. Agreed access, seller permissions and the buyer's intended works affect the useful scope.
- Psi-value
- A measure used to describe linear thermal bridging at a junction. It supports energy calculations using details that reflect the proposed construction.
R
- Refurbishment and demolition asbestos survey
- An investigation scoped around areas affected by intrusive works. HSE survey guidance explains its purpose and the need to plan access appropriately.
- Retrofit assessment
- An assessment gathering information about an existing home's condition, occupancy and energy characteristics. The findings inform discussion of proposed improvement measures.
S
- SAP
- The Standard Assessment Procedure is a government methodology for assessing dwelling energy performance, described in the SAP guidance. Calculations depend on consistent building and services information.
- SBEM
- The Simplified Building Energy Model is used for non-domestic energy calculations within the National Calculation Methodology. Building use and servicing arrangements shape the model inputs.
- Separating construction
- A wall or floor dividing spaces whose sound insulation is being considered. Its performance can depend on workmanship and adjoining elements as well as its specification.
- Smoke shaft
- A shaft forming part of a building's smoke ventilation arrangement. Assessment considers the installed system, accessible components and relevant controls within the agreed scope.
- Solar gain
- Heat entering a building from sunlight through glazing and other exposed surfaces. Orientation, shading and glazing properties affect its contribution to indoor conditions.
- Sound insulation
- The resistance of a construction to sound transmission between spaces. Site performance reflects the assembled building, including junctions and possible leakage paths.
- Surface condensation
- Moisture condensing on an exposed surface when local conditions allow. Surface temperatures, indoor moisture and ventilation all affect the likelihood of occurrence.
- Sustainability statement
- A document explaining a project's approach to environmental topics beyond energy alone. Planning requirements differ by council, so the relevant topics need confirming.
T
- Thermal bridge
- A location where heat flow differs from the surrounding construction because of geometry or materials. Junction calculations can describe its contribution to heat loss.
- Thermal modelling
- Computer-based assessment of how a building responds to changing thermal conditions over time. The model uses stated assumptions for weather, occupancy and building operation.
- Trickle vent
- A small purpose-made ventilation opening often incorporated into a window or adjacent frame. Product airflow data matters when assessing its contribution to background ventilation.
U
- U-value
- A measure of heat transfer through a building element. Calculations use its materials, thicknesses and construction arrangement rather than insulation thickness alone.
V
- Ventilation commissioning record
- A record of checks, measured airflows and settings for an installed ventilation system. It helps identify what was tested and under which conditions.
W
- Water efficiency calculation
- An assessment of predicted water use based on the specified fittings and appliances. Product substitutions may change the result and should be recorded.