To verify the savings from a Demand-Controlled Ventilation (DCV) retrofit in a tertiary building, IPMVP Option C with multiple regression including degree-days plus occupancy (measured through presence counters or badges) is typically the most appropriate approach.

DCV savings depend on real occupancy patterns. The relevant model variables are degree-days (winter/summer weather), occupancy (badge entries, camera counting or smart-building data) and hours (weekdays, weekends, holidays). Multiple regression captures the correlations, allowing the savings to be evaluated by comparing the pre-DCV baseline to the post-DCV reporting period at equal conditions. Typical savings range from 15 % to 30 %.

If badge data are unreliable, fall back on CO2-based occupancy proxies — but document the proxy in the M&V Plan before reporting.