Energy auditor
Competency
The energy auditor shall demonstrate that they have qualifications or experience covering the scope, complexity and thoroughness of the audit
Confidentiality
The energy auditor shall respect all the legal and commercial confidentiality requirements agreed with the organization, which cover all parties involved, such as tenants, maintenance organizations, building occupants.
Objectivity
Objectivity is defined in EN 16247-1, 4.1.3
Transparency
Transparency is defined in EN 16247-1, 4.1.4
Energy audit process
When a sampling method is used, any selected sample of spaces, systems or equipment shall be representative of the whole building or of a group of buildings
NOTE See Informative Annex A: A flow diagram of the energy audit process
5 Elements of the energy audit process
Preliminary contact
An energy auditor must recognize all stakeholders involved in the ownership, management, use, operation, and maintenance of the building, along with their respective influences and interests regarding energy consumption and usage.
NOTE 1 See Informative Annex B: Examples of parties of an energy audit in buildings
The audit's scope must encompass the technical interactions between systems within the building and their relationship with the building itself Focusing on optimizing specific sectors while neglecting others can lead to inaccurate conclusions.
The agreed aims of the energy audit may contain: a) reducing energy consumption and costs; b) reducing environmental impact;
1 prEN 16247-5 is currently not yet published and is under development c) complying with legislation or with voluntary obligations
The scope and boundaries of an energy audit must clearly outline the inclusions, specifying the buildings or sections of buildings to be assessed, the energy services involved, the technical systems examined, any external areas or systems considered, and the relevant energy performance indicators applicable to the audit.
The thoroughness of an energy audit must be mutually agreed upon, as it significantly affects various factors including the duration of the site visit, sample selection, modeling complexity, measurement requirements, metering levels (including sub-metering), identification of energy efficiency improvement opportunities, and the necessary skills of the auditor.
NOTE 2 See Informative Annex C: Examples of the scope, aim and thoroughness of energy audits in buildings.
Start-up meeting
In the initial start-up meeting, the energy auditor will collaborate with the organization to determine key aspects such as the scheduling of site visits, including whether they will occur during or outside of regular working hours, the degree of occupant involvement, any restricted access areas, and the identification of potential health hazards and risks.
The energy auditor should gather essential information from the organization, including the set-points and operational limits for indoor environmental conditions like temperature, airflow, illuminance, and noise, along with any seasonal variations Additionally, they need to understand occupancy patterns for various activities within the building and collect feedback from occupants regarding the building's operational performance and service levels It is also important to obtain any energy certificates related to the building and to determine if any awareness or motivation programs for building occupants have been implemented.
Collecting data
General
The data collection shall be appropriate to the scope of the energy audit.
Information request
The energy auditor shall collect with the organization the following data as required by the scope of the energy audit: a) energy carriers, present and available; b) energy related data:
1) delivered, produced and exported energy, for each energy carrier (for example identify the energy streams for a CHP unit, or for photovoltaic systems where production is used locally or exported);
2) energy consumption data (or readings with related time and date) of any available meters or counters (e.g heat meter, domestic hot water meter, fuel meter, burner hour counter);
3) data from individual metering, if available;
4) short-interval (e.g hourly) energy demand / load curve, if available;
The frequency of the data should be appropriate to the scope and thoroughness of the energy audit Building energy audits typically deal with monthly consumption data
The energy related data should be recorded by the building and control system if available c) adjustment factors affecting energy consumption:
1) climatic data (e.g temperature, degree-days, hygrometry, lighting) from the local building automation and control system (BACS), if available;
To effectively quantify the adjustment factors influencing energy consumption, it is essential for the building control system to document relevant data, such as occupancy times and degree-hours Additionally, it is important to gather information on significant changes that have occurred within the past three years or during the timeframe of the available operational data.
1) the physical form of the building;
2) the spaces – either in dimension and/or in use;
3) the building envelope (renovation of windows, added insulation, etc.);
4) the technical building systems and the areas they serve;
6) occupancy of spaces (different occupancy times, extended hours behaviour and internal loads);
7) set points and occupant behaviour; e) values to be used, adapted to the local /national performance indicators (if relevant):
3) others; f) existing design, operation and maintenance documents and information, such as:
2) any external factors that may influence the energy performance of the building (e.g shading by adjacent trees or buildings);
3) indications of supplied building services (i.e which rooms or zones are heated, cooled, ventilated) on the building lay-out plan;
4) technical building system schematics, indicating the system zones, if any;
6) appliance and component data and ratings; g) the building information model (BIM) and/or design models of the building, if available; h) energy using equipment in the occupied spaces and other internal loads.
Review of the available data
The energy auditor shall review the information collected and provided by the organization
The energy auditor shall review the scope and boundaries of the energy audit if it is deemed appropriate once initial information has been received
The energy auditor shall judge whether or not the information provided by the organization allows the energy audit process to continue and the agreed objectives to be achieved
In cases of missing data, clients will have the option to either provide the necessary information or agree to the auditor making explicit assumptions, which will be thoroughly outlined.
An energy auditor, leveraging their experience and expertise, will select specific energy-using systems and components to evaluate on-site, tailored to the objectives, scope, and depth of the energy audit.
Preliminary data analysis
The energy auditor conducts a comprehensive analysis of collected data to assess the energy balance of the audited object, determine adjustment factors, and establish key energy performance indicators Additionally, they evaluate the distribution of energy consumption based on available measured data and, if sufficient information is present, set an initial energy reference for quantifying the impacts of energy-saving interventions Finally, the auditor plans for further data collection and measurement to be executed during field work.
The energy auditor should develop a preliminary list of energy efficiency improvement opportunities.
Field work
Aim of field work
An energy auditor is responsible for conducting a thorough inspection of the audited object(s), which includes verifying the site against received data and assessing the current and future performance levels of significant building services, such as temperature, humidity, and illuminance The auditor must ensure that technical systems are suitable for their intended purpose and capable of delivering the required service levels Additionally, the performance of these systems should be evaluated, considering aspects like generation, storage, distribution, emission, and control It is also essential to understand the factors influencing changes in these systems, such as seasonal demands, while actively seeking opportunities for energy efficiency improvements and identifying any constraints or restrictions For further guidance, refer to Informative Annex D: Checklist for energy audit field work in buildings.
Conduct
The conduct of an energy auditor during field work is defined in EN 16247-1, 5.4.2.
Site visits
Site visits are defined in EN 16247-1, 5.4.3
The energy auditor requests the organization to facilitate access to building automation and control systems (BACS) and electronic data sources for review, provide authorized support for necessary tests and operations during the energy audit, such as controlling systems and equipment, and ensure access to relevant areas of the building essential for conducting the audit.
Analysis
General
In an energy audit in buildings the auditor shall analyse the energy saving potential according to the scope and aim of the audit
The analysis will provide a comprehensive comparison of each building service's actual performance against the appropriate service levels, including indoor environmental criteria such as temperature, air quality, and illuminance, ensuring that energy-saving measures do not compromise these standards While legislative compliance is essential, any adjustments to service levels, such as modifying indoor temperatures to lower heating or cooling demands, can be made with client agreement Additionally, the evaluation will assess the actual performance of technical systems against a relevant reference and analyze the effectiveness of the building envelope.
When assessing a building's energy performance, it is crucial to evaluate various factors such as insulation levels, thermal bridges, and air tightness Additionally, understanding the interaction between technical systems and the building envelope plays a significant role in achieving optimal energy efficiency.
When assessing energy improvements, auditors must evaluate the interplay between building systems, the envelope, external conditions, and occupant activities, as outlined in EN 15603:2008 They should consider the effects of energy consumption during various occupancy periods and seasons, as changes like lighting replacements can inadvertently increase heating demands while reducing cooling needs Additionally, it is crucial to analyze how energy-saving measures will influence energy performance certificate ratings.
An energy audit must encompass an evaluation of energy supply contracts and the inspection and maintenance requirements for technical equipment, focusing on their influence on energy efficiency and associated costs.
Energy breakdown
An energy auditor provides a comprehensive analysis of energy consumption, costs, and emissions by energy carrier, presented in consistent units such as pie charts Additionally, the auditor breaks down energy end-use by service and other applications, offering both absolute and specific numerical data in uniform energy units If applicable, the report includes an inventory of installed onsite energy production and any energy exported to third parties, detailed in absolute figures.
The energy breakdown must accurately reflect both energy input and usage, clearly distinguishing between energy flows derived from measurements and those based on estimations or calculations.
NOTE 1 See Informative Annex E: Examples of the analysis of energy use in buildings
NOTE 2 See Informative Annex F: Examples of analysis checklist for energy audits in buildings.
Energy performance indicators
The analysis should incorporate the calculation of energy performance indicators, specifically focusing on specific energy use and building-specific baselines It is essential for the energy auditor and the organization to reach a consensus on the energy performance metrics that will be utilized.
NOTE See Informative Annex G: Examples of energy performance indicators in buildings.
Energy efficiency improvement opportunities
The energy auditor shall identify energy efficiency improvement opportunities on the basis of: a) their own expertise; b) comparison against benchmarks if applicable;
This assessment serves as an initial indicator of potential improvement opportunities, focusing on the age and condition of the building and its technical systems, as well as their operation and maintenance It also evaluates the existing technology against the best available options and highlights industry best practices.
NOTE 1 See Informative Annex H: Examples of energy efficiency improvement opportunities in buildings NOTE 2 See Informative Annex I: Examples of analysis and savings calculations in energy audits in buildings.
Report
General
The reporting format shall be targeted such that it is relevant to both technical and executive personnel
Energy savings interventions can be categorized into four key areas: a) high-cost measures, such as improvements to the building shell and technical equipment; b) low-cost measures, including adjustments to operational modes and reduction of supply losses; c) training and awareness initiatives aimed at end-users to promote behavior change and motivation; and d) assessments of comfort, health, and well-being, focusing on factors like temperature, humidity levels, and room size.
Content of report
NOTE See Informative Annex J: Examples of the reporting of an energy audit in buildings
The report should include recommendations for future measurement and verification methods for the energy saving interventions proposed See Annex K for an example.
Final meeting
The requirements for a final meeting are defined in EN 16247-1, 5.7
Energy audit process flow diagram
The main steps of the energy audit process are shown below
Examples of parties of an energy audit in buildings
Examples of parties involved in a building energy audit and their roles are shown below
There needs to be suitable authority from the energy audit client to instruct the appropriate organizations and people to support the energy auditor
Party Possible recipient of the energy audit
Data provider Involved in meetings the
In the field of property management, various roles contribute to the effective operation of buildings and apartments Key personnel include property managers, facilities managers, engineering services managers, and maintenance staff, all of whom ensure smooth daily operations Additionally, security staff and permanent occupant staff play vital roles in maintaining safety and functionality Temporary occupants, such as patients or clients in commercial settings, may have different needs compared to residential tenants Understanding these dynamics is essential for optimizing property management strategies.
Examples of the scope, aim and thoroughness of energy audits in buildings
The energy audits in buildings may have different levels of thoroughness as shown below
Specific System/Area LIMITED WIDE Every System / All
Assessment Light touch Detailed Detailed Potential
General screening of saving potential GENERAL
C.2 Examples of how to define the energy audit aim
To enhance energy savings, consider adjusting ventilation operation schedules, which requires a detailed audit to identify specific timing changes Additionally, optimizing boiler plant operations can significantly boost overall efficiency.
Listing specific saving measures: c) for each individual energy saving measure the estimated energy saving in each energy carrier to be shown in the report
C.3 Examples of how to define the energy audit scope
Limited energy audit scopes focus on specific areas, such as conducting a technical audit on a single system, like the ventilation and air conditioning in Building A or the chiller plant in Building C Additionally, these audits can be narrowed down to a single energy service, for example, assessing the heating systems across Buildings A, B, and C.
A comprehensive energy audit should encompass all energy-consuming systems within a building, including technical systems for heating, cooling, and domestic hot water This wide-ranging assessment also evaluates the building envelope, technical building services, appliances, and equipment to ensure an in-depth analysis of overall energy usage.
C.4 Examples of how to define the energy audit thoroughness:
To optimize energy efficiency, it is essential to spend adequate time on-site assessing low-cost savings and identifying major energy uses This includes reviewing parameters such as time schedules and temperature set points that affect energy consumption within the building automation and control system (BACS), rather than relying on individual measurements Conducting selective sample measurements, like checking room temperatures, can provide valuable insights Additionally, estimating energy savings can be effectively achieved using straightforward energy calculation tools.
To ensure optimal energy efficiency, it is essential to conduct a comprehensive survey of all energy systems and equipment, dedicating sufficient time on-site for thorough assessments This includes performing extensive measurements of temperatures, air flows, and electricity consumption, as well as utilizing dynamic calculation tools to simulate building energy performance effectively.
Examples of checklists for energy audit field work in buildings
In visiting the building and systems, the energy auditor should gather suitable information to evaluate actual performance of the audited object and to assess feasibility of improvements
This checklist contains examples for the auditor’s field work (what to inspect) but it can be also used for defining the scope of the audit or initial data collection
Main item Sub-items to inspect Check
The building envelope Heating related properties
Daylighting related properties including glazing type
The heating system(s) and control Room equipment
The domestic hot water system(s) and control Fixtures
The cooling system(s) and control Room equipment
The ventilation and air conditioing system and control Room equipment
The lighting system and control
Internal transport systems Elevators, escalators, moving walkways
Freeze-protection systems and control Heated areas, trace heating Electric energy distribution Transformers, UPS, reactive power correction
Other utilities Steam, compressed air, medical gases
The building automation and control system (BACS)
Other energy using systems Swimming pools
This checklist below can be used for the auditor’s field work as a guide to the places to visit (where to go)
Main item Places to be visited Check
The heating system(s) and control the boiler room heat distribution rooms distribution manifolds and channels The domestic hot water system(s) and control the boiler room storage individual domestic
The cooling system(s) and control the chiller room or the roof where cooling equipment is located
The ventilation and air conditioning system and control mechanical rooms where air handling units are located technical spaces
The lighting system and control sample rooms, by usage common areas external illuminated areas
Domestic appliances sample residential dwellings
Office appliances sample rooms, by usage data centres
Internal transport systems elevators, escalators, moving walkways…
Freeze-protection systems and control power distribution panels protected areas heated areas, trace heating,
Electric energy distribution the transformer room power distribution rooms
The steam generation plant includes essential components such as steam distribution headers, condensate collection tanks, and pumps Additionally, it features a compressor room with compressed air headers and drains, as well as facilities for the swimming pool plant and other service production rooms, ensuring efficient distribution throughout the system.
The building automation and control system (BACS) electronic access
Other energy using systems Swimming pools
When visiting building envelope elements, it is essential to evaluate several key aspects: first, assess the U-value along with potential improvements and restrictions, including accessibility, height, and the risk of thermal bridges, while considering conflicts with building use and aesthetics Second, examine shading options and their implications for glazed elements and cooling efficiency Additionally, consider the building's thermal inertia, air tightness, and the condition of joints and thermal bridges to ensure optimal energy performance and comfort.
NOTE This is not the same as indoor spaces visit The focus here is on the building elements and their properties
Indoor spaces can be categorized into several types based on their usage and characteristics Typical examples include apartments, offices within buildings, and classrooms in schools, which serve specific functions Additionally, spaces such as auditoriums, conference centers, and restaurants are designed with high airflows and ventilation rates to ensure comfort and safety Furthermore, areas with heavy energy consumption, characterized by high electrical loads, are critical for efficient energy management and sustainability.
3) pool areas, etc special rooms;
Outdoor areas: a) main entrances; b) loading areas; c) parking area lighting and car heating; d) electrically heated areas / snow melting
The energy auditor needs documents and drawings of the building and its technical systems for the audit work
Auditors must recognize that available documents may not reflect accurate or up-to-date information; thus, it is crucial to verify all essential details during site inspections.
Examples of relevant documents: a) building:
2) Building zoning; i) asset register; ii) building energy log book; iii) energy performance certificate; iv) display energy certificate; b) systems (for each within the scope of the audit):
3) operating settings list; i) air conditioning inspection report; ii) mechanical and electrical schematics;
1) delivered energy records and/or bills (for electricity, gas, liquid and solid fuels as approporiate);
5) other metering records (any other than delivered, like readings from hour counters);
Examples of the analysis of energy use in buildings
E.1 Overview of the energy use in a building
The building energy audit may cover all or some of the technical building systems and energy flows depending on the agreed scope of the energy audit
Energy consumption in a building is closely associated with the provision of comfort services such as heating, domestic hot water, and ventilation, as well as the activities conducted within the space and the operation of appliances, including household devices, computers, and office machinery Additionally, other forms of energy usage contribute to the overall energy demand in the building.
The energy supply chain encompasses several key components: first, energy needs for comfort services are influenced by the building envelope's energy balance, which considers losses, gains, and interactions with technical systems Second, energy requirements for other services are established through a precise accounting process that evaluates the number, power, and usage duration of devices and appliances Third, the energy delivered is transformed and distributed by technical systems to meet these needs Finally, energy is supplied to the building via various energy carriers.
Technical systems are typically analyzed as comprising several key subsystems: generation, which produces energy; storage, which decouples the timing of energy generation and usage to optimize the sizing and power of the generation plant; distribution, which facilitates the transfer of energy; and room equipment, including heat emitters, cooling elements, and lighting, along with their control systems that manage energy transfer into the serviced space.
The energy flows of a building are illustrated in the Figure E.1 below
Figure E.1 — Energy flows of a building
E.2 Analysis of the energy use in a building
An energy audit in a building involves modeling or calculations to assess the current energy use profile and identify opportunities for improving energy efficiency The level of energy modeling or calculation should align with the scope and depth of the audit conducted.
The modelled energy use should ideally be checked for consistency with actual measured energy consumption
The calculation shall ideally reflect actual values and conditions (use, occupancy, indoor temperatures, climate, etc), not standardized ones
To enhance energy efficiency in comfort services, it's essential to first establish and validate the building model against real energy usage Following this, energy performance indicators, including specific energy consumption (kWh/m².y) and the efficiencies of various systems and subsystems, should be compared to relevant reference values to identify potential energy-saving opportunities.