Residential
Residential Performance
The thermal and whole home energy performance of new and existing residential buildings, including NatHERS, star ratings and Whole of Home assessment.
Certified Energy Knowledge System
Explore clear definitions for the building performance, compliance, sustainability, carbon, environmental systems, design modelling and planning terms used throughout the Certified Energy knowledge system.
Each definition is intentionally concise and shows where a term belongs within the wider system. Detailed guidance, assessment pathways and project context remain within the relevant Certified Energy Knowledge Hubs.
Explore the GlossaryKnowledge System Map
The Certified Energy knowledge system separates related but distinct areas of building performance, compliance, sustainability and environmental assessment. Each glossary term belongs to one of the systems below, helping readers understand where a concept sits before following more detailed guidance.
Residential
The thermal and whole home energy performance of new and existing residential buildings, including NatHERS, star ratings and Whole of Home assessment.
Residential
Regulatory pathways, assessments and documents used to demonstrate residential energy compliance, including BASIX, DTS, VURB and applicable ACT requirements.
Commercial
Energy efficiency compliance pathways for commercial buildings under the NCC, including Section J, Deemed to Satisfy provisions, JV3 and related documentation.
In Use Performance
The measured or estimated performance of buildings during operation, including NABERS Energy, Water, Waste, Indoor Environment and strategic assessment pathways.
Voluntary Frameworks
Broader sustainability standards and rating frameworks for homes, buildings and communities, including Passive House, Green Star, WELL and LEED.
Carbon Assessment
The assessment and reporting of embodied, operational and whole life greenhouse gas emissions associated with materials, construction and building use.
Water and Site Systems
Stormwater, drainage and water sensitive design systems used to address environmental performance and planning requirements, including WSUD, STORM, SDA and SMP.
Environmental Modelling
Building physics and environmental simulation used to test daylight, airflow, thermal comfort, glare and other design performance conditions.
Planning Assessment
Spatial, visual and solar analysis used to understand how a proposed development may affect its site, surroundings, views and neighbouring properties.
Project Outputs
The reports, certificates, statements, models, submissions and supporting information produced or assembled for assessment, approval and project delivery.
These systems may interact within a project, but they do not have the same purpose. A compliance pathway is distinct from a performance rating, a carbon assessment is distinct from operational energy measurement and a planning assessment is distinct from building physics modelling.
Glossary Purpose
The Certified Energy Building Performance Glossary is a reference guide to terminology used across residential energy performance, building compliance, operational ratings, sustainability frameworks, carbon assessment, environmental systems, design modelling and planning analysis. Each term is placed within the part of the Certified Energy knowledge system to which it belongs.
Definitions are intentionally concise. The glossary is designed to identify what a term means, distinguish it from similar concepts and direct readers towards the appropriate Knowledge Hub where detailed regulatory, technical or project guidance belongs. This helps preserve clear boundaries between compliance pathways, performance ratings, assessment methods and project documentation.
Technical language used across building performance, compliance, sustainability, carbon reporting, environmental systems, design physics, planning assessments and project documentation.
Use it as a quick reference, browse by system or alphabet and follow the distinction notes where related terms may otherwise be confused.
Detailed explanations, assessment pathways, regulatory context and project guidance remain within the relevant Certified Energy Knowledge Hubs and service pages.
Glossary Navigation
Browse the glossary in the way that best suits your project or question. Search alphabetically when you know the term, explore by knowledge system when you know the subject area or begin with the most frequently used building performance terminology.
Knowledge Structure
Explore terms grouped by Residential Performance, Commercial Compliance, Carbon, Environmental Systems, Design & Physics and other Certified Energy knowledge domains.
Alphabetical Index
Jump directly to glossary entries using an alphabetical index of all defined building performance and sustainability terms.
Most Referenced
Start with the most frequently referenced terms across residential energy performance, commercial compliance, carbon assessment and environmental modelling.
Browse by System
Browse terminology according to the Certified Energy system it belongs to. Each link leads to the relevant definition in the A–Z glossary, while the system groupings preserve the distinction between performance, compliance, sustainability, carbon, environmental assessment and design analysis.
Residential
Residential
Commercial
In Use Performance
Rating Frameworks
Emissions and Materials
Water and Site Systems
Environmental Modelling
Planning Assessment
Project Outputs
A term may be relevant to more than one project stage, but it is listed under the system that owns its primary meaning. The full glossary entry may also identify related systems, supporting documents or commonly confused terms.
Featured Terms
These frequently referenced terms represent the main assessment systems, rating frameworks and modelling disciplines used across Certified Energy projects. Select a term to move directly to its full glossary entry and related Knowledge Hub pathway.
Residential Performance
A national framework used to assess the thermal performance of Australian homes.
Residential Compliance
The NSW sustainability assessment framework for applicable residential development.
Residential Performance
An assessment of fixed household energy systems beyond the thermal performance of the building shell.
Existing Homes
A rating used to describe the assessed energy performance of an existing home.
Commercial Compliance
The NCC energy efficiency provisions applying to relevant commercial building classes.
Commercial Compliance
A verification method comparing a proposed building with a compliant reference building.
Operational Performance
A national rating system used to measure aspects of operational building performance.
Carbon
Greenhouse gas emissions associated with materials, construction, maintenance and end of life processes.
Carbon
A structured method for assessing environmental impacts across defined life cycle stages.
Sustainability Frameworks
A performance based building standard focused on comfort, energy demand and building fabric.
Design & Physics
Computational modelling used to examine airflow, temperature and fluid behaviour within defined conditions.
Design & Physics
Simulation used to assess natural light availability and visual conditions within buildings.
Planning & Site Intelligence
Spatial analysis used to identify locations from which a site or development may be visible.
Planning & Site Intelligence
A broader assessment of how development may affect visual character, views and sensitive receptors.
Environmental Systems
Water sensitive urban design integrating stormwater and water management with site planning.
Knowledge Boundaries
Some building performance terms are closely related but belong to different systems, assessment pathways or project stages. These concise comparisons help preserve the distinction between terms before directing readers to their full glossary entries.
NatHERS assesses the thermal performance of the building shell. Whole of Home considers the energy performance of major fixed systems such as heating, cooling, hot water, lighting, solar and batteries where relevant.
NatHERS is a national residential energy rating framework. BASIX is a NSW compliance framework that addresses broader sustainability targets, with NatHERS commonly used to support the thermal performance component.
A Home Energy Rating commonly refers to the assessed performance of an existing home. New home NatHERS assessments generally support design and compliance before construction.
Section J refers to the NCC energy efficiency provisions for relevant commercial buildings. JV3 is one verification method that may be used to demonstrate compliance through comparative building performance modelling.
A DTS pathway follows prescribed NCC provisions. JV3 uses modelling to compare the proposed design against a compliant reference building and is not itself a prescriptive DTS pathway.
NABERS measures or estimates operational performance for eligible building types. NatHERS assesses residential thermal performance and Whole of Home energy outcomes within the residential system.
NABERS Strategic supports performance planning, readiness and improvement pathways. It is distinct from a formal accredited NABERS rating based on eligible building data and the applicable rating rules.
Embodied carbon is associated with materials, construction, maintenance and end of life processes. Operational carbon arises from energy and other activities during building use.
Life Cycle Assessment follows a defined scope, methodology, life cycle boundary and impact framework. A carbon calculator may provide a simplified estimate without representing a complete LCA.
CFD examines airflow, temperature distribution and fluid behaviour. Thermal comfort assessment considers how environmental and personal factors may affect occupant comfort under defined conditions.
Daylight modelling assesses natural light conditions within or around buildings. Shadow diagrams show the extent and movement of shadows cast by development at selected dates and times.
Viewshed analysis identifies areas of potential visibility. Visual Impact Assessment considers the broader effect of development on views, visual character, receptors and landscape context.
Passive House is a performance based building standard with its own criteria and certification pathway. NatHERS is an Australian residential energy rating framework and may support NCC compliance.
Green Star evaluates broader sustainability outcomes through defined rating tools. NABERS focuses on measured or estimated operational performance within eligible building categories.
WELL centres on health and wellbeing conditions within places and organisations. Green Star assesses a broader range of sustainability outcomes for buildings, homes, communities and operational assets.
A certificate is a formal document issued under a defined scheme or process. A report records assessment findings, assumptions, methods or compliance evidence and does not automatically function as a certificate.
The correct term depends on the project location, building type, assessment purpose and documentation pathway. Similar language should not be treated as interchangeable without confirming the relevant regulatory or technical context.
Complete Reference
Browse concise definitions of terms used across building performance, compliance, operational ratings, sustainability frameworks, carbon assessment, environmental systems, design physics, planning analysis and project documentation. Major entries identify the system they belong to, direct readers towards related Knowledge and clarify distinctions where similar terminology may otherwise cause confusion.
Definition
A concise explanation of what the term means within its relevant Australian building or planning context.
System
The primary Certified Energy knowledge domain that owns the meaning and purpose of the term.
Related Knowledge
A pathway to the relevant Knowledge Hub or service page where detailed guidance and project context belong.
Not the Same As
A distinction note used only where related language may otherwise blur separate systems, methods or documents.
Regulated Document
An ACT Energy Efficiency Rating Statement records energy efficiency information prepared under the applicable Australian Capital Territory pathway. For a proposed home, the statement may be based on plans, specifications and NatHERS assessment information. The required document and process depend on whether the rating supports construction, approval, sale or disclosure.
Design Physics Concept
Airflow refers to the movement of air through or around a building, room or site. It may be influenced by wind, pressure differences, openings, ventilation systems, internal heat sources and surrounding structures. Airflow can be examined through calculations, observations or computational modelling depending on the project question.
Documentation Term
An assessment pathway is the recognised method used to evaluate a project against a regulation, rating framework, technical criterion or planning requirement. The appropriate pathway depends on factors such as jurisdiction, building classification, project stage, development type and intended outcome. Different pathways may require different models, evidence and project documents.
Residential Compliance
BASIX means the Building Sustainability Index. It is the NSW sustainability assessment framework used for applicable residential development and addresses water, energy and thermal performance requirements. A BASIX Certificate records the project commitments generated through the assessment and is submitted through the relevant development approval pathway.
Commercial Operational Performance
A Building Energy Efficiency Certificate, commonly shortened to BEEC, is a disclosure document used under Australia’s Commercial Building Disclosure framework for applicable commercial office space. It includes the required building energy efficiency information and must be prepared and registered through the prescribed process where the disclosure obligations apply.
Building Physics Concept
The building envelope is the physical boundary separating conditioned or occupied internal spaces from external conditions or spaces with different environmental conditions. It commonly includes relevant walls, roofs, floors, windows, doors and other elements that influence heat transfer, air movement, moisture and daylight.
Residential Performance Concept
Building fabric refers to the physical construction elements that shape a building’s thermal response. These may include walls, roofs, ceilings, floors, insulation, glazing, frames, thermal mass and shading. In residential energy assessment, the fabric is modelled with the building layout, orientation and climate to estimate heating and cooling demand.
Documentation Term
A certificate is a formal document issued through a defined assessment, rating, compliance or disclosure process. Its meaning depends on the scheme under which it is produced. A certificate may record an assessed result, project commitments, rating outcome or regulated declaration, but it should only be used for the purpose recognised by the relevant framework.
Design & Physics
Computational Fluid Dynamics, commonly shortened to CFD, is a numerical modelling method used to examine the movement of air or other fluids within defined conditions. In building projects, CFD may be used to investigate airflow, wind behaviour, ventilation, temperature distribution, pressure and local environmental conditions around or within a proposed design.
Carbon Metric
Carbon dioxide equivalent, written as CO₂e, is a common unit used to express the climate effect of different greenhouse gases on a comparable basis. Emissions are converted using the applicable global warming potential values and reported as an equivalent quantity of carbon dioxide over the defined assessment period.
Compliance Term
A compliance pathway is the recognised method used to demonstrate that a project satisfies an applicable regulatory requirement. Depending on the jurisdiction and project type, this may involve prescribed provisions, an approved verification method, a Performance Solution or another accepted form of evidence. The pathway should be confirmed before modelling and documentation are prepared.
Documentation Term
A compliance report documents how a project has been assessed against identified regulatory provisions or performance requirements. It may record the project scope, assessment pathway, modelling assumptions, calculations, specifications and required design responses. Its required format and supporting evidence depend on the relevant jurisdiction, building type and approval process.
Daylight Metric
Daylight autonomy is an annual daylight metric describing how often a point or area achieves a specified illuminance level using daylight alone during an occupied schedule. The threshold, analysis period and calculation method must be defined when results are reported. Related metrics may evaluate performance across multiple analysis points or provide partial credit below the target.
Design & Physics
Daylight modelling uses a digital representation of a building, its openings, materials, orientation and surrounding context to assess natural light conditions. The analysis may examine illuminance, daylight availability, annual daylight metrics, direct sunlight or glare under defined sky, time and occupancy assumptions.
Environmental Systems
Drainage refers to the collection, conveyance, detention, treatment or discharge of water from a site or building. In development assessment, drainage design may address roof water, surface runoff, lawful discharge, overland flow and connections with existing infrastructure. Requirements depend on the site, authority, jurisdiction and proposed development.
Compliance Pathway
Deemed to Satisfy, commonly shortened to DTS, refers to prescribed NCC provisions that provide an accepted pathway for satisfying the relevant Performance Requirements when correctly applied. DTS provisions may contain defined construction, insulation, glazing, sealing, services or documentation requirements depending on the building classification and part of the NCC being addressed.
Carbon
Embodied carbon refers to greenhouse gas emissions associated with building materials and construction processes across defined life cycle stages. Depending on the assessment boundary, it may include raw material extraction, manufacturing, transport, construction, maintenance, replacement, demolition, waste processing and disposal. Results are commonly expressed as carbon dioxide equivalent.
Carbon Data Source
An Environmental Product Declaration, commonly shortened to EPD, presents quantified environmental information about a product using a defined life cycle assessment methodology and product category rules. An EPD may provide data for embodied carbon assessment, but its declared unit, system boundary, geographic relevance, validity and product coverage should be checked before use.
Cross System Term
Environmentally Sustainable Design, commonly shortened to ESD, is a broad project approach that considers environmental performance through planning, design, construction and operation. It may involve energy, water, materials, indoor environment, carbon, climate response and site systems. ESD is an umbrella term rather than one assessment, certificate or regulatory pathway.
Design Physics Concept
Glare is visual discomfort or reduced visibility caused by excessive brightness, strong contrast or bright light within the field of view. In building analysis, glare may arise from direct sunlight, bright windows, reflective surfaces or electric lighting. Assessment methods depend on the space, viewpoint, time period and intended use.
Carbon Metric
Global Warming Potential, commonly shortened to GWP, is a measure used to compare the climate effect of a greenhouse gas with carbon dioxide over a defined time horizon. In life cycle assessment, the term may also describe the climate change impact category used to report results in carbon dioxide equivalent.
Sustainability Framework
Green Star is an Australian sustainability rating system administered by the Green Building Council of Australia. Its rating tools address different asset types and project stages, with criteria that may cover energy, carbon, water, materials, health, resilience, nature and broader sustainability outcomes. The applicable tool and certification pathway depend on the project.
Residential Sustainability Framework
Green Star Homes is a residential sustainability standard within the Green Star system. It provides requirements for assessing broader home outcomes such as health, resilience, energy performance and environmental impact. The framework has its own evidence and certification process and may incorporate information from other residential assessments where recognised.
Existing Home Performance
A Home Energy Rating assesses the energy performance of an existing Australian home using information collected from the dwelling and entered into approved assessment software. The resulting certificate may include thermal performance, estimated energy use, running costs, greenhouse gas emissions and opportunities for improvement, depending on the applicable assessment scope.
Daylight Metric
Illuminance is the quantity of light falling onto a surface and is measured in lux. In daylight modelling, illuminance may be calculated at selected points or across an analysis grid to understand whether a space receives an appropriate level and distribution of natural light under defined conditions.
Infrastructure Sustainability Framework
The IS Rating Scheme is a sustainability rating framework administered by the Infrastructure Sustainability Council. It is used to evaluate economic, social and environmental performance across infrastructure planning, design, construction and operation. The applicable rating tool, credits, evidence requirements and verification process depend on the infrastructure asset and project stage.
Commercial Compliance
JV3 is an NCC verification method used to assess the energy performance of an applicable commercial building design. It uses defined modelling rules to compare the calculated annual energy consumption of the proposed building with a reference building that satisfies the relevant provisions. Its suitability depends on the building classification, design and adopted NCC requirements.
Sustainability Framework
LEED means Leadership in Energy and Environmental Design. It is an international green building rating system developed by the U.S. Green Building Council. LEED provides rating systems for different building types and project stages, with credits addressing matters such as energy, water, materials, location, indoor environmental quality and broader sustainability performance.
Carbon Assessment Method
Life Cycle Assessment, commonly shortened to LCA, is a structured method used to evaluate environmental impacts across defined stages of a product, building or system life cycle. An LCA establishes its goal, scope, functional basis and system boundary before compiling inventory data, assessing selected impact categories and interpreting the results.
Planning Analysis Concept
A line of sight is a direct visual path between an observation point and a target location, structure or landscape feature. Line of sight testing may consider terrain, vegetation, buildings and the height of the observer or proposed development. It can support viewshed analysis, viewpoint selection and visual impact assessment.
Sustainability Framework
The Living Building Challenge is a holistic, performance based certification program administered by Living Future. It is structured around regenerative outcomes across interconnected categories known as Petals. Certification requires projects to follow the applicable standard, provide supporting evidence and demonstrate the required outcomes through the relevant certification process.
Daylight Metric
Luminance describes the amount of light emitted, transmitted or reflected by a surface in a particular direction. It helps represent the apparent brightness of windows, materials, lighting and other surfaces within a field of view. Luminance values and contrast may be considered when assessing visual conditions and glare.
Thermal Comfort Variable
Mean radiant temperature represents the combined radiant temperature effect of the surfaces surrounding a person. It accounts for heat exchanged by radiation with elements such as walls, floors, ceilings, glazing and nearby heat sources. It is commonly considered with air temperature, air speed, humidity, clothing and activity when evaluating thermal comfort.
Assessment Method
Modelling is the use of a simplified physical, numerical or digital representation to assess how a building, system or site may perform under defined conditions. Results depend on the selected method, input data, geometry, assumptions, boundary conditions and assessment purpose. A model should be interpreted within the limits of the adopted methodology.
Operational Performance
NABERS is a national rating system used to measure and compare the environmental performance of eligible Australian buildings and tenancies. Depending on the available rating tool and asset type, NABERS may assess energy, water, waste or indoor environment performance using defined rules, operational data and independent accredited assessment.
Operational Energy Rating
NABERS Energy measures the operational energy efficiency and associated greenhouse performance of an eligible building or tenancy. The rating is calculated under the applicable NABERS rules using verified energy data and relevant building information. The available rating scope and benchmarking method depend on the building type and part of the asset being rated.
Operational Water Rating
NABERS Water measures and benchmarks the operational water efficiency of an eligible building using verified water consumption and relevant building data. It helps identify how efficiently water is being used compared with similar assets. The available rating scope, exclusions and evidence requirements depend on the applicable NABERS rules.
Operational Waste Rating
NABERS Waste evaluates how effectively an eligible building measures, manages and diverts operational waste. The rating uses defined waste data and evidence requirements to assess performance under the relevant NABERS rules. It may support benchmarking, performance improvement and clearer reporting of waste outcomes.
Operational Indoor Environment Rating
NABERS Indoor Environment evaluates selected indoor environmental conditions within an eligible building or tenancy. Depending on the applicable rules and rating scope, it may consider indoor air quality, lighting quality, temperature, thermal comfort and acoustic quality using measured data, surveys and supporting evidence.
Performance Strategy
NABERS Strategic refers to advisory work that uses NABERS methods, rating readiness, available data and performance objectives to help an organisation prepare for future ratings or improve asset performance. The scope may include data review, gap analysis, rating estimates, portfolio planning and recommendations, depending on the building and intended outcome.
Operational Performance Advisory
NABERS estimation is an indicative assessment of potential rating performance using available building, consumption and operational information. It may help identify data gaps, test readiness or inform performance planning before a formal rating is undertaken. The reliability of an estimate depends on the quality and completeness of the available information.
Embodied Carbon Rating
NABERS Embodied Carbon is a national rating pathway used to measure and compare greenhouse gas emissions associated with eligible building materials and construction activities. A formal rating must follow the current NABERS rules, evidence requirements and accredited assessment process. Its scope is distinct from the operational energy, water, waste and indoor environment rating tools.
Residential Performance
NatHERS means the Nationwide House Energy Rating Scheme. It provides nationally consistent methods and accredited software for assessing the thermal performance of Australian homes. A thermal star rating is calculated from the dwelling design, construction, orientation and local climate. NatHERS also supports Whole of Home assessment through a separate energy performance score.
Regulatory Framework
NCC Volume One is the part of the National Construction Code primarily applying to Class 2 to Class 9 buildings and certain associated structures. It contains Performance Requirements and accepted compliance pathways addressing matters including energy efficiency. The adopted NCC edition and jurisdictional variations should be confirmed for each project.
Carbon
Operational carbon refers to greenhouse gas emissions associated with energy and other relevant activities during the use of a building or asset. It may include emissions from heating, cooling, ventilation, hot water, lighting, equipment and other operational loads, depending on the adopted assessment scope and energy sources.
Thermal Comfort Variable
Operative temperature is a combined measure representing the thermal effect of surrounding air temperature and radiant surface temperatures on an occupant. It is used in thermal comfort analysis because people exchange heat with both the air and nearby surfaces. The calculation method may also consider air movement and the applicable comfort standard.
Planning & Site Intelligence
Overshadowing is the reduction of direct sunlight caused when a building, structure, landform or vegetation casts shadow over another area. In planning assessment, overshadowing may be tested at nominated dates and times to understand potential effects on neighbouring properties, private open space, windows, communal areas or public spaces.
Sustainability Framework
Passive House is a performance based building standard focused on energy demand, indoor comfort and building fabric. Projects are designed and assessed against defined criteria using the Passive House Planning Package and supporting documentation. Certification requires independent review through the applicable Passive House certification process rather than the use of one prescribed construction method.
Compliance Pathway
A Performance Solution is an NCC compliance pathway that demonstrates satisfaction of the relevant Performance Requirements through an accepted assessment method rather than relying solely on Deemed to Satisfy provisions. Its preparation may involve calculations, modelling, comparison with DTS provisions, expert judgement or other evidence appropriate to the defined performance based design brief.
Documentation Term
Project documentation is the coordinated information used to describe, assess, approve and deliver a proposed development. It may include architectural drawings, schedules, specifications, engineering information, product data, reports, certificates and supporting evidence. The documents required for an assessment depend on the pathway, jurisdiction, project stage and intended submission.
Commercial Compliance
A reference building is a comparative model configured in accordance with the applicable NCC verification method. It generally retains defined characteristics of the proposed building while applying prescribed reference inputs and compliance settings. Its calculated performance provides the benchmark against which the proposed building is assessed under the relevant modelling pathway.
Thermal Comfort Variable
Relative humidity expresses the amount of water vapour present in air as a percentage of the maximum amount the air could hold at the same temperature. It can influence thermal comfort, condensation risk, material behaviour and indoor environmental conditions. Its significance depends on temperature, ventilation, moisture sources and the assessment purpose.
Documentation Term
A report is a document that records the scope, inputs, methodology, assumptions, results and conclusions of an assessment. Its content depends on the discipline and project purpose. A report may support design development, regulatory review, planning assessment, certification or submission, but its title alone does not determine its legal or approval status.
Environmental Planning Document
A Sustainable Design Assessment, commonly shortened to SDA, is a planning document used by some Victorian councils to explain how a proposed development addresses applicable environmentally sustainable design objectives. Its scope may include energy, water, indoor environment, materials, transport, waste, urban ecology and construction management. The required content depends on the council, development type and planning pathway.
Commercial Compliance
Section J is the part of NCC Volume One addressing energy efficiency for applicable Class 2 to Class 9 buildings. Its provisions cover relevant aspects of building fabric, glazing, sealing, air conditioning, ventilation, lighting, power and energy monitoring. Compliance may use applicable Deemed to Satisfy provisions, verification methods or a Performance Solution.
Planning & Site Intelligence
Shadow diagrams are drawings or model outputs showing shadows cast by existing and proposed development at selected dates and times. They are used in planning assessment to examine changes to solar access for neighbouring windows, private open space, communal areas, public places or solar energy systems. Submission requirements vary between planning authorities.
Residential Performance Benchmark
A 6 Star NatHERS rating indicates the modelled thermal performance level achieved by a residential design on the NatHERS scale. Six stars was an earlier minimum benchmark for many new homes and may remain relevant to older approvals, existing certificates or particular project contexts. Current requirements should be confirmed for the project location and adopted code.
Environmental Planning Document
A Sustainability Management Plan, commonly shortened to SMP, is a detailed planning document used by some Victorian councils for developments requiring a comprehensive environmentally sustainable design response. It records sustainability objectives, design initiatives, modelling results, evidence and implementation commitments across the relevant planning categories. Required scope and supporting assessments vary by council and project.
Documentation Term
A statement is a document or formal written declaration addressing a defined project matter, assessment result or compliance position. Its authority depends on the framework, person or organisation issuing it and the purpose for which it was prepared. A statement may support a submission without functioning as a certificate or complete technical report.
Legacy Stormwater Tool
STORM refers to the former Melbourne Water calculator used to estimate whether stormwater treatment measures for smaller Victorian developments met nominated treatment objectives. The original calculator has been replaced by BlueFactor. STORM may still appear in earlier reports, planning conditions, project files and common industry language, so the required current tool should be confirmed before assessment.
Environmental Systems
Stormwater is rainfall runoff from roofs, paved areas, roads, landscaped surfaces and other parts of a catchment. Development can change its volume, flow rate, quality and discharge path. Stormwater assessment may therefore consider collection, detention, reuse, treatment, overland flow, lawful discharge and effects on receiving waterways or drainage infrastructure.
Documentation Term
A submission is the coordinated package of information provided to an authority, certifier, rating body, client or other reviewer for a defined project purpose. It may include drawings, application forms, models, reports, certificates, statements, calculations and supporting evidence. Submission requirements depend on the assessment pathway and receiving organisation.
Planning & Site Intelligence
Sun eye diagrams are viewpoint based solar access illustrations showing the apparent path or position of the sun relative to buildings, obstructions and a selected observation point. They may be used to examine whether direct sunlight can reach a window, open space or other location during nominated periods under applicable planning controls.
Residential Performance Benchmark
A 7 Star NatHERS rating describes a residential design that achieves seven stars on the NatHERS thermal performance scale. It reflects the modelled heating and cooling demand of the home’s building fabric under standardised occupancy and climate assumptions. Whether seven stars is required depends on the adopted NCC edition, jurisdiction, building type and applicable transitional arrangements.
Commercial Disclosure Document
A Tenancy Lighting Assessment, commonly shortened to TLA, records information about the lighting system within applicable commercial office space. It may form part of the documentation required for a Building Energy Efficiency Certificate under the Commercial Building Disclosure framework. The assessment scope and disclosure requirements depend on the applicable legislation and premises.
Design & Physics
Thermal comfort refers to an occupant’s experience of the surrounding thermal environment. Assessment may consider air temperature, radiant temperature, air speed, humidity, clothing and activity under defined conditions. Thermal comfort modelling is used to test how a design or operating strategy may affect comfort, rather than simply measuring heating or cooling energy demand.
Residential Performance Concept
Thermal performance describes how a building responds to heat gains, heat losses and changing climate conditions. It is influenced by the building fabric, glazing, insulation, thermal mass, orientation, shading, air movement and layout. In NatHERS, thermal performance is expressed through modelled heating and cooling loads and a star rating.
Carbon
Upfront carbon refers to greenhouse gas emissions arising before a building or asset begins operation. It commonly includes emissions associated with product manufacture, transport to site and construction or installation activities within the defined assessment boundary. The included life cycle stages and data sources should be stated whenever upfront carbon results are reported.
Planning & Site Intelligence
Viewshed analysis is a spatial modelling method used to identify locations from which a site, structure or proposed development may be visible. It considers terrain and may incorporate buildings, vegetation, observer height and development height where suitable data is available. Results indicate potential visibility rather than the significance of the visual effect.
Planning Analysis Concept
A visual catchment is the broader geographic area within which a site or proposed development may potentially be seen. Its extent is influenced by landform, vegetation, buildings, viewing distance and the scale or height of the development. It may be refined through viewshed modelling, field observation and viewpoint analysis.
Planning & Site Intelligence
A Visual Impact Assessment evaluates how a proposed development may affect views, visual character, landscape context and identified receptors. It may draw on site inspection, photography, viewpoint analysis, mapping, visualisations and viewshed modelling. The required method and level of detail depend on the planning authority, development type, location and potential visual sensitivity.
Residential Compliance
VURB means Verification Using a Reference Building. It is an NCC residential verification method that compares the calculated performance of a proposed building with a reference building configured according to the applicable NCC rules. It may provide an alternative compliance pathway where the project is suitable for comparative whole building energy modelling.
Sustainability Framework
WELL is an evidence based building and organisational framework focused on health and wellbeing. Its requirements and strategies address aspects of the built environment and organisational policy that may influence occupant experience, including air, water, light, thermal conditions, movement, nourishment, sound, materials, mind and community. Certification follows the applicable WELL pathway and verification process.
Carbon
Whole life carbon refers to greenhouse gas emissions associated with a building or asset across its defined life cycle. It generally brings together embodied carbon and operational carbon within an identified study period and system boundary. The included stages, scenarios, energy assumptions, data sources and treatment of benefits beyond the project boundary should be clearly reported.
Residential Performance
Whole of Home is a NatHERS assessment of the energy performance of major fixed household systems. It considers heating and cooling, hot water, lighting, swimming pool and spa equipment where applicable and onsite energy generation or storage where included. The result is separate from the NatHERS thermal star rating for the building shell.
Environmental Systems
Water Sensitive Urban Design, commonly shortened to WSUD, integrates urban planning and development with water cycle management. It may address stormwater quality, runoff volume, water conservation, reuse, landscape integration and protection of waterways. The required measures and assessment method depend on the jurisdiction, planning controls, site conditions and scale of development.
System Based Index
This index groups glossary terms according to the Certified Energy system that owns their primary meaning. It provides a concise ontology reference for readers, search engines and AI systems while preserving the boundaries between performance, compliance, sustainability, carbon, environmental assessment, design physics and project documentation.
Residential
Terms describing the thermal, whole home and existing home energy performance of residential buildings.
Residential
Regulatory pathways and documents used to demonstrate residential energy compliance.
Commercial
NCC energy efficiency provisions, pathways and comparative modelling terms for commercial buildings.
In Use Performance
Rating and advisory terms relating to eligible buildings in operation.
Voluntary Standards
Broader rating and certification frameworks for homes, buildings, infrastructure and organisations.
Emissions and Materials
Terms used to define, calculate and report material, construction and operational greenhouse gas emissions.
Water and Site Systems
Planning and technical terms relating to stormwater, drainage and sustainable design documentation.
Environmental Modelling
Concepts and modelling methods used to assess light, airflow, temperature and occupant conditions.
Planning Assessment
Spatial, visual and solar analysis used to support development assessment and site understanding.
Project Outputs
Terms describing assessment pathways, evidence, reports and formal project outputs.
Some terms may support more than one project system, but they remain indexed under the knowledge domain that owns their primary purpose. The relevant glossary entry identifies related systems where a project requires more than one assessment or document.
Frequently Asked Questions
An ESD glossary defines terminology used across environmentally sustainable design, building performance, energy compliance, sustainability frameworks, carbon assessment, environmental systems and related planning disciplines.
The Certified Energy glossary also identifies the knowledge system to which each term primarily belongs and directs readers to the relevant Knowledge Hub where more detailed guidance is available.
Building projects often involve several related assessment systems at the same time. A residential project may require thermal modelling, a compliance certificate and a Whole of Home assessment, while a commercial building may involve NCC compliance and later operational performance ratings.
The systems may exchange information, but they do not necessarily use the same methodology, produce the same document or answer the same project question.
No. NatHERS is a national residential energy rating framework used to assess the thermal performance of homes and, separately, Whole of Home energy outcomes.
BASIX is a NSW residential compliance framework addressing water, energy and thermal performance. A NatHERS assessment may support the thermal component of a BASIX assessment, but the two systems are not interchangeable.
No. NABERS is primarily used to measure or estimate operational performance for eligible buildings and tenancies, including energy, water, waste and indoor environment performance where an applicable rating tool is available.
NatHERS belongs to the residential energy performance system and is used to assess the thermal performance and Whole of Home energy outcomes of Australian homes.
No. Embodied carbon refers to greenhouse gas emissions associated with materials, manufacturing, transport, construction and other defined building life cycle stages.
Operational energy is the energy used while a building is occupied and operating. Operational carbon refers to the greenhouse gas emissions associated with that energy use and any other operational activities included within the assessment boundary.
No. A modelling report records the assessment scope, methodology, assumptions, inputs, results and conclusions relevant to the project.
A certificate is issued through a defined regulatory, rating or disclosure process and performs a specific recognised function. Modelling may support preparation of a certificate, but a modelling result does not automatically become one.
These systems answer different project questions. Compliance determines whether a design satisfies an applicable regulatory requirement or accepted pathway.
Performance assessment evaluates how a building, home or system performs under defined conditions, while carbon assessment measures greenhouse gas emissions within a stated life cycle boundary. Separating the systems protects the meaning of each assessment and its resulting documentation.
Use the Related Knowledge link within the relevant glossary entry. The associated Knowledge Hub explains the assessment pathway, technical method, regulatory context, required project information and practical considerations in greater detail.
Where the appropriate pathway remains unclear, Certified Energy can review the available plans and project information before confirming which assessment, report or certificate may apply.
Project-Specific Terminology
The correct assessment terminology can depend on the project location, building classification, development type, adopted regulation, rating framework and intended submission. These answers provide general guidance and should not be treated as confirmation of the pathway or documentation required for an individual project.
Related Knowledge
The glossary defines terminology and protects the boundaries between related systems. The following knowledge areas provide the deeper regulatory, technical and project guidance that sits beyond each concise definition.
Residential Performance
Owns the assessment of residential thermal performance, NatHERS star ratings, Whole of Home energy outcomes and energy ratings for existing homes.
Explore Residential Energy Performance →Residential Compliance
Owns the regulatory pathways and documentation used for applicable residential projects, including BASIX, VURB, DTS and ACT energy efficiency certification.
Explore Residential Compliance →Commercial Compliance
Owns NCC energy efficiency compliance for applicable commercial buildings, including Section J, Deemed to Satisfy pathways, JV3 and supporting project documentation.
Explore Commercial Energy Compliance →Operational Performance
Owns the measurement, estimation and strategic improvement of eligible operational building performance across energy, water, waste and indoor environment categories.
Explore NABERS Knowledge →Carbon
Owns the assessment and reporting of material, construction and whole life greenhouse gas emissions using defined boundaries, data sources and life cycle methods.
Explore Embodied Carbon Knowledge →Environmental Modelling
Owns building physics and environmental simulation used to examine daylight, airflow, temperature, glare, thermal comfort and other defined design conditions.
Explore Design & Physics →Planning Assessment
Owns spatial, visual and solar analysis used to understand development visibility, visual effects, view relationships, overshadowing and surrounding site conditions.
Explore Planning & Site Intelligence →Knowledge Boundaries
Each knowledge area owns a distinct assessment purpose. A project may require several systems to work together, but compliance, performance, sustainability, carbon, environmental modelling and planning analysis should not be treated as interchangeable services or documentation pathways.
Project Context
Building performance terminology often depends on the project location, building classification, development type, assessment purpose and stage of documentation. Similar terms may lead to different assessment pathways, reports or certificate requirements.
Send the available plans, project information or authority request if you are unsure which assessment or documentation pathway applies. Certified Energy can review the project context before confirming the appropriate scope.
Request a Project ReviewLast reviewed: June 2026
This glossary is maintained as part of the Certified Energy building performance knowledge system. Definitions may be updated as terminology, rating frameworks, regulatory pathways and assessment methods change.
