Short answer：Energy management systems can support monitoring and control without universally guaranteeing 30% bill savings. Compare a suitable baseline, operating hours, weather and equipment condition.
Build a reproducible baseline
Record consumption, bills, area, occupancy and hours and distinguish tariff changes from energy changes. EMSD audit guidance emphasises measurements and analysis rather than one before-and-after bill.
Include upkeep and control risks
Count sensors, subscriptions, calibration, electrical work and replacements. Automated control should preserve necessary ventilation, lighting and safety services with suitable professional settings and fallback arrangements.
Before deciding
- Compare the same measurement boundary
- Keep control-change and maintenance dates
- Separate energy savings from financial payback
Sources and method
Sources support the specific rules described. Checklists and hypothetical calculations are editorial explanations, not measured market results or individual approvals.
Revision：Removed unsupported experience, case outcomes and statistics; corrected the topic-specific rules and limitations described above.
Scope：General information only, not personalised legal, tax, immigration, admissions or investment advice.