Meeting Office Compliance is no longer just about lux levels; it is about strict energy management. Part L of the Building Regulations effectively outlaws "dumb" on/off light switches in large commercial offices, demanding automated sensor systems to slash carbon emissions.
Daylight Harvesting (Constant Illuminance)
Luminaires located within 3 meters of a window must be grouped into a separate control zone equipped with a daylight sensor, dynamically dimming the LEDs in response to incoming natural sunlight.
If the sun is beaming through the floor-to-ceiling glass of a modern office, the desks near the window do not need artificial light. A daylight harvesting sensor continuously monitors the ambient lux level on the desk. As the sun rises, the sensor smoothly dims the LED panels above the window desks down to 10% output, while keeping the panels deep in the core of the building at 100%. This guarantees a maintained 500 Lux everywhere while saving massive amounts of energy.
Granular PIR Presence Detection
To eliminate wasted energy, open-plan offices must utilize high-density PIR (Passive Infrared) presence detection, ensuring lights only illuminate the specific desk clusters currently occupied by staff.
If an accountant is working late at 8:00 PM, they should not have to turn on the lights for the entire 10,000 sq ft floor plate. Modern DALI systems link one PIR sensor to every four desks. As the accountant walks to their desk, only the lights immediately above them activate. The rest of the office remains in darkness. If the sensor detects no movement for 20 minutes, it automatically turns the cluster off.
Integration with HVAC via BACnet/KNX
Premium office fit-outs leverage the lighting PIR sensors to control the building's Heating, Ventilation, and Air Conditioning (HVAC) systems via a central BMS (Building Management System).
The lighting sensors already know exactly which meeting rooms are empty. By passing this occupancy data via BACnet to the HVAC system, the building automatically stops pumping expensive air conditioning into empty rooms. This holistic, data-driven approach to building management is essential for achieving an "Excellent" BREEAM rating.