Standards & methodology
ISO 50015:2014
ISO 50015
The governance standard for measurement and verification — seven principles, a six-step process, and what a defensible M&V plan must contain before you run a single calculation.
What the standard covers
ISO 50015:2014 (Measurement and verification of energy performance of organizations) defines how organisations should govern M&V — not the maths itself, but the principles, plan, documentation, and accountability that make results defensible.
Key points:
- Usable with or without a formal ISO 50001 energy management system
- Applies at any scale and for any energy type
- Does not prescribe a calculation method — but requires that the chosen method is documented and justified
- Designed to work alongside IPMVP: ISO 50015 provides governance; IPMVP provides calculation options
The seven M&V principles
Every M&V plan must comply with all seven. They are not optional.
| # | Principle | In practice |
|---|---|---|
| 1 | Accuracy and uncertainty | Results include an uncertainty statement — not just a bare number |
| 2 | Transparency and reproducibility | Another competent practitioner can reproduce results from the documentation alone |
| 3 | Data management | Meters, sensors, gaps, and outliers are planned and documented |
| 4 | Competence | The practitioner declares competence and works within it |
| 5 | Impartiality | Conflicts of interest disclosed in the plan and all reports |
| 6 | Confidentiality | Data restrictions that affect results are noted |
| 7 | Appropriate methods | Methods follow established good practice; choice is documented with rationale |
The six-step process
1. Establish and document the M&V plan
↓
2. Data gathering
↓
3. Verify implementation of the measure
↓
4. Conduct M&V analysis
↓
5. Report results and issue documentation
↓
6. Review — repeat if needed
↑________________________|The plan is the foundation. Everything else traces back to it.
What the M&V plan must contain
Scope and purpose — which organisation or site is covered, why M&V is being conducted, who receives results, and what confidentiality applies.
Energy Performance Improvement Actions (EPIAs) — for each measure: description, expected savings, baseline, responsibility, and physical verification method.
M&V boundaries — physical, organisational, or virtual limits on what is included in the savings claim.
Energy baseline — established before the improvement wherever possible, including the normalization method for weather, production, and other relevant variables.
Data-gathering plan — for each data element: source, accuracy, collection frequency, validation method, and contingency for data loss.
Weather data (§5.9)
ISO 50015 explicitly recognises three approaches for weather data used in normalization:
- A degree day database or nearest reliable measurement point
- Computation from a temperature database of the nearest weather station
- Computation from a local temperature meter
Using a degree day database is a recognised data collection method under the standard — not a shortcut.
Impartiality statement — required in both the plan and all reports.
How ISO 50015 fits with IPMVP and ASHRAE GL14
| Layer | Standard | Covers |
|---|---|---|
| Governance | ISO 50015 | Principles, process, plan structure, uncertainty |
| Calculation | IPMVP | Options A–D, savings equation, independent variables |
| Quality | ASHRAE GL14 | CV(RMSE), NMBE, R² thresholds |
| Reporting | ISO 50047 | Savings calculation and communication |
ISO 50015 + IPMVP Option C + ASHRAE GL14 + ISO 50047 is the standard stack for building-level verification.
For the data-gathering and analysis steps, a documented degree day source with billing-period matching supports reproducibility (Principle 2) and the §5.9 weather data requirement. Ed runs the regression, surfaces model quality metrics, and calculates adjusted-baseline savings — based on the principles of ISO 50015, not as a complete M&V plan document.