Standards & methodology
ISO 50000 family
The ISO 50000 family
Ten international standards that cover energy audits, certified energy management, measurement, verification, and savings reporting — and how they fit together.
How the series is organised
The ISO 50000 family is not a checklist you work through once. It is a lifecycle: understand consumption, manage it systematically, measure performance, verify results, and report savings.
- Where is energy wasted? → ISO 50002 (energy audits)
- How do we manage it systematically? → ISO 50001 (EnMS), with ISO 50004 and ISO 50005 for implementation guidance
- How do we measure improvement? → ISO 50006 (EnPIs and baselines) and ISO 50015 (M&V governance)
- How do we calculate the savings? → ISO 50047 (savings determination)
- Who verifies the certifiers? → ISO 50003 (requirements for certification bodies)
- What about energy services? → ISO 50007 (guidelines for ESCOs and energy service providers)
Standards at a glance
| Standard | What it covers | Type |
|---|---|---|
| ISO 50001 | Energy management systems — requirements | Certifiable |
| ISO 50002-1 | Energy audits — general requirements | Requirements |
| ISO 50002-2 | Energy audits — buildings | Requirements |
| ISO 50002-3 | Energy audits — processes | Requirements |
| ISO 50003 | Requirements for bodies certifying EnMS | For certifiers |
| ISO 50004 | Guidance for implementing ISO 50001 | Guidance |
| ISO 50005 | Phased implementation of ISO 50001 | Guidance |
| ISO 50006 | EnPIs and energy baselines | Guidance |
| ISO 50007 | Energy services | Guidance |
| ISO 50015 | Measurement and verification of energy performance | Guidance |
| ISO 50047 | Determination of energy savings | Guidance |
Two widely used companion protocols sit alongside the ISO family — not published by ISO, but referenced throughout M&V practice:
| Protocol | Publisher | Role |
|---|---|---|
| IPMVP | EVO | Calculation options and savings equation |
| ASHRAE Guideline 14 | ASHRAE | Statistical quality thresholds for regression models |
The energy management lifecycle
1 — Understand the current state
ISO 50002 defines how to conduct a structured energy audit: where energy goes, what drives consumption, and which improvement opportunities offer the best return. The audit also produces the baseline billing data that later M&V work depends on.
2 — Manage energy systematically
ISO 50001 is the certifiable core — policy, targets, responsibilities, and a Plan-Do-Check-Act review cycle. ISO 50004 explains how to implement it; ISO 50005 offers a phased route for organisations that cannot adopt everything at once.
3 — Define what you measure
ISO 50006 specifies how to choose energy performance indicators (EnPIs) and establish baselines. For weather-sensitive buildings, the model-based approach — regression against degree days and other relevant variables — is the approach auditors most often expect.
4 — Verify whether improvements worked
ISO 50015 governs the M&V process: seven principles, a six-step workflow, and a mandatory M&V plan. IPMVP provides the calculation options; ASHRAE Guideline 14 sets the pass/fail bar for regression model quality.
5 — Report the savings
ISO 50047 defines how to calculate and report savings — organisation-wide (top-down) or measure by measure (bottom-up), with three normalization methods for weather and production changes.
The M&V stack
Measurement and verification in practice layers four standards and protocols:
ISO 50015 — Governance
Is the process documented, reproducible, and impartial?
↓
IPMVP — Calculation
Which parameters are measured? What is the savings equation?
↓
ASHRAE GL14 — Quality
Does the regression model meet CV(RMSE) and NMBE thresholds?
↓
ISO 50047 — Reporting
How is the savings figure calculated and communicated?This combination is the standard approach for ESCO contract verification and ISO 50001 audit evidence. Where weather normalization is required, degree days matched to billing periods are the independent variable most practitioners use — and the part of the workflow that needs a documented, reproducible data source.
Which standard do you need?
| Your situation | Start here |
|---|---|
| EU EED audit obligation, no ISO 50001 | ISO 50002 |
| Implementing ISO 50001 from scratch | ISO 50001 + ISO 50004 + ISO 50002 for the energy review |
| Phased EnMS rollout | ISO 50005 |
| Setting up EnPIs and baselines | ISO 50006 |
| Writing an M&V plan for an ESCO contract | ISO 50015 + IPMVP + ASHRAE GL14 |
| Calculating and reporting savings | ISO 50047 |
| Pursuing ISO 50001 certification | ISO 50001 + ISO 50003 (to find an accredited certification body) |