ISO 50001 step-by-step plan

From energy review to certificate in hand. This step-by-step plan, based on the Plan-Do-Check-Act cycle , guides you through the whole process. Whether you work with an accredited body such as Kiwa , TÜV  or DNV .

On this page

Below we cover the full ISO 50001 process in 9 phases. For each phase we explain what you do, which actions you take, and where companies often get stuck. Use this overview to quickly jump to the right phase.

1. Preparation and management commitment

What you do: You start with a quick scan: where do we stand on energy management? What are our energy costs? Do we already have insight into our consumption? What would be a realistic goal?

Then you secure commitment from management. ISO 50001 only works if the board backs it and releases budget.

Concrete actions:

• Quick scan of the energy situation (half a day with a consultant or internally)
• Make the business case: what does it cost, what does it deliver?
• Proposal to the management team (MT) or board: approval and budget
• Appoint an energy manager or project leader (this person will lead the project)
• Form a project team (energy manager, facilities, production, finance)

Time investment: 2-4 weeks

Pitfall: management says “yes” but does not free up time or budget. Then the project stalls. Get an explicit commitment: X hours per week, €Y budget, deadline Z.

2. Energy review (energy diagnosis)

What you do: This is the most important phase. You map in full where your energy goes. This is not “we use 500 MWh a year” but a detailed overview per process, department or machine.

Concrete actions:

• Map energy flows (electricity, gas, heat, transport, compressed air)
• Install meters where you currently have no visibility (sub-meters, data loggers)
• Collect historical consumption data (at least 12 months)
• Identify the largest consumers (Pareto principle: 20% of your assets cause 80% of consumption)
• Calculate energy performance per relevant unit (kWh per product, per m², per FTE)

Example: A manufacturing company finds:

• 35% of energy goes to compressors (compressed air for machines)
• 25% goes to climate control (factory heating and cooling)
• 20% goes to the production process itself (ovens, presses)
• 10% goes to lighting
• 10% other (office, canteen, etc.)

Now you know where to focus.

Time investment: 4-8 weeks

Cost: if you hire an external expert for measurements and analysis: €5k-€15k

Pitfall: too little detail. If you only know “we use a lot”, you cannot steer. You need granular data.

3. Significant energy aspects (SEUs)

What you do: You determine which processes or assets are your Significant Energy Uses (SEUs). These are the areas where you will take action.

Criteria for an SEU:

• High consumption (for example above 10% of total consumption)
• Large saving potential (old, inefficient equipment)
• High variability (strong fluctuations you can optimise)

Example SEUs:

• Compressor system (35% of consumption, 15-year-old compressors, estimated saving potential 20%)
• Factory climate installation (25% of consumption, thermostat not optimised)
• Production line A (20% of consumption, only active during the day shift but stays on standby at night)

For each SEU, you document:

• Current consumption
• Saving potential
• Priority (high/medium/low)

Time investment: 1-2 weeks

Output: SEU register with 5-15 significant aspects (depending on the complexity of the business)

4. Energy baseline and objectives

What you do: You set an energy baseline: this is where we stand now. This becomes your reference point. You often choose a recent year as the baseline (for example 2024).

Then you set objectives:

• Strategic objective (e.g. “15% CO2 reduction in 3 years”)
• Operational objectives per SEU (e.g. “10% lower compressor consumption within 18 months”)

Objectives must be SMART: Specific, Measurable, Acceptable, Realistic, Time-bound.

Example objectives:

• Reduce total electricity consumption from 520 MWh (2024) to 440 MWh (2027) = 15% reduction
• Reduce gas consumption from 80,000 m³ to 70,000 m³ = 12.5% reduction
• Reduce energy consumption per product made from 12 kWh/unit to 10 kWh/unit

Time investment: 1-2 weeks

Pitfall: unrealistic objectives. If you set “30% savings in 1 year” without major investment, it will not happen. Be ambitious but realistic.

5. Energy performance indicators (EnPIs)

What you do: You define Energy Performance Indicators (EnPIs) to measure progress. These are the KPIs of your energy management.

Examples of EnPIs:

• kWh per unit produced
• MJ per m² of lettable floor area (property)
• GJ per FTE (offices)
• kWh per guest night (hotels)
• PUE (Power Usage Effectiveness) for data centres

You choose EnPIs that are:

• Relevant to your organisation
• Influenceable (you can improve them)
• Measurable (you have the data)

Reporting frequency: usually monthly or quarterly. You create dashboards or reports that show your EnPIs and compare them with your objectives.

Time investment: 1 week

Output: EnPI list with 3-8 indicators, measurement plan (who measures what and when), reporting format

6. Action plans and implementation

What you do: For each SEU you create an action plan: what we will do, when, who is responsible, what it costs and what it delivers.

Examples of measures:

• Quick wins (low-hanging fruit):

  • LED lighting with motion sensors (ROI often under 2 years)
  • Optimising climate settings (thermostat control, night setback)
  • Insulating pipes and tanks (small budget, quick effect)
  • Reducing operating hours (production line not running 24/7 when not needed)

• Medium term (1-3 year ROI):

  • Variable speed drives on motors (especially where speed varies)
  • Heat recovery from production processes
  • New, efficient compressors
  • Rooftop solar PV panels (with the SDE++ subsidy, Stimulation of Sustainable Energy Production and Climate Transition)

• Strategic (longer ROI but major impact):

  • Full replacement of the HVAC system
  • Process innovation (a different production method that uses less energy)
  • On-site energy generation (combined heat and power (CHP), large-scale solar panels)

You schedule these measures in phases. Not everything at once, but a rolling programme.

Time investment: 2-4 weeks for planning, then ongoing implementation (months to years)

Budget: this varies widely. Quick wins can cost €5k-€20k. Major investments €50k-€500k+. Create a multi-year programme with phasing.

7. Documentation and system setup

What you do: You build the Energy Management System (EnMS). This is the structure that keeps energy management running.

What you document:

• Energy policy: a short statement from the board (1 page): these are our ambitions, and this is how important energy is to us
• Scope: which sites, processes and energy types fall under the EnMS?
• Roles and responsibilities: who does what? (energy manager, management team, operators)
• Procedures: how do we measure? How do we report? How do you carry out an internal audit? How do you deal with deviations?
• SEU register, EnPI dashboards, action plans (you already have these)

Important elements:

• Competence: people who work with SEUs must be trained. Document which training is needed.
• Communication: how do you inform employees about energy objectives and results? (for example a monthly newsletter, a dashboard on the shop floor)
• Operational control: how do you make sure day-to-day operations are energy efficient? (checklists, work instructions)

Software tools: Many companies use energy management software for monitoring and reporting. Examples: Metrix, EnMS tools, EnergyCAP, or custom dashboards in Power BI.

Time investment: 3-6 weeks

Pitfall: documenting too much or too little. You do not need a bulky manual, but you do need clear procedures. Ask yourself: “could someone else pick this up if the energy manager leaves?“

8. Internal audit and management review

What you do: Before the external auditor arrives, you test yourself whether your system works. You will find a detailed explanation of what clause 9.2 requires, energy-specific audit points and a practical checklist on the page internal audit ISO 50001.

Internal audit:

• Check whether procedures are being followed
• Check whether measurements take place as agreed
• Check whether action plans are on track
• Identify deviations (things that are not going to plan)

An external person (a consultant) or a trained internal auditor can do this. If you already have ISO 9001 or 14001, you can also have that auditor do this.

Management review: The board discusses progress. Questions:

• Are we meeting our energy objectives?
• What is the ROI of measures so far?
• Are there new risks or opportunities?
• Do we need to adjust course?

This is formally recorded in the minutes.

Time investment: 1-2 weeks for internal audit + management review

Pitfall: skipping this phase. If you go straight to the external audit without an internal check, you risk findings that you could have prevented.

9. External certification audit

What you do: The external auditor (certification body) visits for the certification audit. This takes place in two stages:

Stage 1 (documentation audit): The auditor checks whether your documentation is complete. This can often be done remotely (video call plus sending documents).

• Is the energy policy in place and approved by the board?
• Has the energy review been done?
• Have SEUs been determined and documented?
• Have objectives been formulated as SMART?
• Is there an action plan?

If this is in order, you move on to stage 2.

Stage 2 (on-site audit): The auditor visits your site (1-3 days, depending on size).

• Interviews with the energy manager, management team and operators
• Tour of the SEUs: show where the large consumers are and which measures you have taken
• Check measurements: are the meters installed, are they read, and is the data correct?
• Check monitoring: show EnPI dashboards, reports and trend analyses
• Check actions: what have you implemented? What are the results?

Outcomes:

• No nonconformities: you are certified (rare on the first attempt)
• Minor nonconformities: small issues that you must resolve within 90 days, after which you receive the certificate
• Major nonconformities: serious problems that you must resolve and have re-audited

Usually there are a few minors. This is normal. Resolve them, send evidence, and you get your certificate.

Time investment: 2-4 days (stage 1 + stage 2 + preparation)

Certification cost: €8k-€25k depending on company size and certification body

ISO 50001 timeline by company size

Combining with ISO 14001 or ISO 9001

If you already have ISO 14001 (environment) or ISO 9001 (quality), ISO 50001 goes faster.

With ISO 14001: Energy is part of environmental impact. You already have:

• Management system structure (PDCA)
• Documentation processes
• Internal auditors
• Management review process

You add:

• Energy review (more detailed than what you do for 14001)
• SEUs and EnPIs (specific to energy)
• Energy policy (can be combined with the environmental policy)

Time saving: 30-40%. Instead of 6 months, you do it in 4 months.

With ISO 9001: Less overlap, but you know the principle. You have document control, audit procedures and management commitment.

Time saving: 15-20%

Integrated audit: If you hold several standards, the certification body can carry out an integrated audit. One auditor checks ISO 9001, 14001 and 50001 in one visit. This saves costs and time.

Common mistakes when implementing ISO 50001

1. Too little management commitment

ISO 50001 only works if the board takes it seriously. If the energy manager has to do everything alone without budget or mandate, it fails.

Solution: make a business case. Show that this costs X, delivers Y, and that we earn it back in Z years.

2. Too little detail in the energy review

“We use 500 MWh” is not enough. You need to know where that 500 MWh goes. Otherwise you cannot steer.

Solution: invest in measurement. Sub-meters, data loggers, monitoring software. This costs €5k-€20k but is crucial.

3. Unrealistic objectives

“We save 40% in 1 year” sounds good but is often not achievable without huge investment.

Solution: set realistic objectives. 10-20% in 3 years is ambitious but achievable for most companies.

4. Only quick wins, no structural programme

Replacing lighting with LEDs is good, but not enough. You need a multi-year programme with continuous improvement.

Solution: action plans for the short, medium and long term. Not only year 1, but also years 2 and 3.

5. No continuous monitoring

You install meters but nobody looks at the data. Then you do not know whether measures work.

Solution: report monthly or quarterly. A dashboard where the management team and energy manager see the EnPIs. If there is a deviation, act immediately.

Checklist: are you ready for ISO 50001 certification?

Before you invite the external auditor, check:

Energy review:

• Full energy review completed (all energy flows mapped)
• Largest consumers identified
• Historical data collected (at least 12 months)

SEUs and objectives:

• SEUs determined and documented (5-15 aspects)
• Energy baseline established
• SMART objectives formulated and approved by the board

EnPIs and monitoring:

• EnPIs defined (3-8 indicators)
• Measurement plan drawn up (who measures what and when)
• Dashboards or reports set up
• At least 3 months of data collected

Action plans:

• Action plans per SEU (what, who, when, costs, returns)
• At least some quick wins implemented
• Results of measures measured

Documentation:

• Energy policy approved by the board
• Scope defined
• Roles and responsibilities documented
• Procedures described (measuring, reporting, audit, deviations)
• Competence and training arranged

System:

• Internal audit carried out, findings resolved
• Management review held, minutes available
• Communication to employees (everyone knows the energy objectives)

If you have ticked 90%+, you are ready for the external audit.

What happens after ISO 50001 certification?

Your certificate is valid for 3 years. But every year there is a surveillance audit (control audit):

• Year 1: Certification audit (full)
• Year 2: Surveillance audit (lighter check)
• Year 3: Surveillance audit
• Year 4: Recertification audit (full, renewal for 3 years)

The surveillance audit checks:

• Are you meeting your energy objectives?
• Are the EnPIs on track?
• Are action plans being carried out?
• Is there continuous improvement?
• Have deviations from the previous audit been resolved?

This costs 1-2 days of audit per year and €5k-€15k.

Continuous improvement: ISO 50001 is not a project with an end date. It is a system. Every year you set new objectives, carry out new measures and keep improving.

That is where the real value lies: not the certificate itself, but the ongoing process of saving and optimising.

More information

• Costs and timeline: detailed cost overview per phase
• Energy review: how to map your energy use
• Energy aspects (SEUs): how to determine significant energy aspects
• EnPIs: energy performance indicators with examples
• Requirements: what the standard requires exactly
• Audit: what happens during the certification audit

Sources

• ISO 50001:2018 : the official ISO standard for energy management
• NEN: ISO 50001 : the Dutch standards organisation
• Dutch Accreditation Council (Raad voor Accreditatie) : list of accredited certification bodies