Since June 2022, lighting control has moved from best practice to regulatory requirement for UK hotel projects. The 2021 edition of Part L Building Regulations introduced mandatory lighting controls for non-domestic buildings for the first time — fundamentally changing how specifiers approach hotel lighting design.
For architects and M&E consultants, understanding these requirements is essential. Hotels present particular challenges: 24-hour operation, diverse space types, guest experience expectations, and the need for both aesthetic excellence and regulatory compliance.
This guide covers what you need to know about Part L lighting control requirements for hotel projects — from mandatory controls to metering options to SBEM compliance considerations.
Part L Volume 2 (Buildings Other Than Dwellings) applies to all hotel new builds, extensions, and major refurbishments in England. The lighting requirements focus on three areas: efficacy, controls, and metering.
General lighting must achieve an average efficacy of 95 luminaire lumens per circuit-watt. This is measured at the luminaire, not the lamp — meaning losses from reflectors, diffusers, and optical systems are included.
Display lighting (accent, feature, and decorative lighting) must achieve 80 light source lumens per circuit-watt, or the installed power must not exceed 0.3W per square metre.
For hotel projects, the display lighting allowance is particularly relevant. Decorative pendants in restaurants, feature lighting in lobbies, and accent lighting throughout public areas all fall under this category.
Paragraph 6.63 of Approved Document L states that unoccupied spaces must have automatic controls to switch lighting off. This applies throughout hotels — from back-of-house corridors to meeting rooms to guest bathrooms.
The requirement specifies automatic controls "to turn the general lighting off when the area is not in use (e.g. through presence detection)."
Paragraph 6.64 requires daylight-linked controls (photo-switching or dimming) for general lighting in spaces receiving significant natural light. This applies:
Within 6 metres of window walls
Beneath rooflights covering 10% or more of the roof area
For hotels, this affects lobbies, restaurants, corridors with external glazing, conference rooms, and any other daylit spaces. The controls must be separate from non-daylit zones.
Part L requires energy metering for all general and display lighting. This can be achieved through:
Dedicated kWh meters per circuit
Local power meters integrated with lighting controllers
A lighting management system that calculates energy consumed and makes data available to the BMS
The third option is significant for hotel projects. Intelligent lighting control systems with energy monitoring can satisfy metering requirements without separate meters on every circuit — simplifying installation and reducing costs.
The Simplified Building Energy Model (SBEM) is the standard compliance tool for non-domestic buildings under Part L. When calculating a building's energy performance, SBEM expects to see occupancy detection and daylight sensors specified.
Lighting control affects SBEM calculations in several ways:
Control factors SBEM applies control factors that reduce the calculated energy consumption when controls are specified. A well-designed control system with occupancy sensing, daylight dimming, and time scheduling can achieve a control factor of 0.7 — representing a 30% reduction in calculated lighting energy.
Parasitic loads Control system power consumption (sensors, processors, network equipment) is included in calculations. Well-designed systems minimise parasitic loads while maximising control functionality.
Activity profiles Different hotel spaces have different operating hours built into SBEM. Guest rooms, public areas, back-of-house, and conference facilities each have distinct profiles affecting the calculation.
For specifiers, the key message is clear: lighting controls are no longer optional extras that might improve an SBEM result. They're mandatory requirements that must be properly specified to demonstrate compliance.
Different hotel areas have distinct compliance considerations:
While hotel guest rooms follow residential lighting standards in some jurisdictions, Part L Volume 2 applies fully to UK hotels. Automatic controls must switch off lighting when rooms are unoccupied — typically via occupancy sensing, card key systems, or a combination.
Key-card control systems that switch off lighting (and HVAC) when guests leave the room satisfy the automatic-off requirement while providing energy management functionality that operators value.
Lobbies typically have extensive glazing, triggering daylight control requirements within 6 metres of windows. Separate zoning is required for daylit and non-daylit areas.
The 24-hour nature of hotel lobbies means occupancy sensing alone may not provide significant savings — but daylight harvesting and time-scheduled scene changes can reduce consumption substantially.
Restaurant lighting creates particular challenges. The atmosphere-critical nature of dining spaces requires sophisticated scene control, while Part L demands automatic controls and daylight response in glazed areas.
The solution lies in systems that separate compliance functionality (daylight harvesting, occupancy sensing) from aesthetic control (scene presets, dimming). Intelligent systems can harvest daylight automatically while maintaining the overall light level and atmosphere the designer intended.
Meeting rooms present the clearest case for occupancy-controlled lighting. Spaces that may sit empty for hours between bookings offer substantial savings through automatic-off controls.
Daylight harvesting is similarly effective in naturally-lit conference rooms, reducing artificial lighting when large windows provide adequate illumination for meetings and presentations.
Kitchens, corridors, offices, stores, and plant rooms must all have automatic-off controls. These spaces offer the most straightforward compliance path — occupancy sensors with appropriate timeout periods provide both regulatory compliance and genuine energy savings.
The Carbon Trust estimates lighting accounts for up to 55% of electricity consumption in hotels. Much of this is in back-of-house areas where lights remain on regardless of occupancy. Automatic controls address this directly.
Hotel corridors present a nuanced requirement. While automatic-off is mandatory, corridors providing access to guest rooms need to maintain minimum illumination for safety and wayfinding.
Part L allows for setback operation — reducing light levels when unoccupied rather than switching off completely. Systems can dim corridor lighting to 20-30% when unoccupied, providing adequate wayfinding illumination while achieving significant energy savings.
LENI (Lighting Energy Numeric Indicator) measures predicted annual energy consumption per square metre (kWh/m²/year). It considers:
Installed power density
Operating hours
Control factors (daylight, occupancy, scheduling)
Parasitic power
The LENI approach is particularly valuable for hotels where some spaces may use decorative luminaires that don't achieve 95 lm/cW individually. With comprehensive controls, the overall system can still comply via the LENI route.
LENI calculations are more complex than simple efficacy checks, requiring detailed information about control strategies and operating patterns. However, they can enable more creative lighting designs while maintaining compliance.
Based on our experience with hotel lighting control, several strategies consistently support Part L compliance:
Map the 6-metre daylight zone from all significant glazing. Ensure lighting circuits and control zones align with this boundary, allowing daylit areas to respond independently.
Even in 24-hour spaces like lobbies, occupancy sensing provides data for SBEM calculations and enables setback modes during quiet periods. In intermittently-used spaces like meeting rooms and back-of-house areas, occupancy control delivers both compliance and genuine savings.
Systems that calculate and report energy consumption can satisfy metering requirements without dedicated kWh meters on every circuit. This simplifies installation and provides ongoing energy monitoring capability.
In atmosphere-critical spaces like restaurants, design control systems where daylight harvesting and occupancy sensing work behind the scenes, maintaining the designer's intended appearance while automatically adjusting to conditions.
Building Control will want to see how lighting controls deliver compliance. Prepare documentation showing control zones, sensor locations, setpoint strategies, and how the system meets each Part L requirement.
For architects and M&E consultants specifying hotel projects, Part L fundamentally shapes the approach to lighting control:
Lighting control should be discussed at RIBA Stage 2, not retrofitted at Stage 4. Control zones affect circuit layouts; daylight requirements influence room planning; metering strategies impact distribution board design.
Lighting control has moved from FF&E to base build. The control system is part of the building's compliance package, requiring the same attention as HVAC controls or fire detection.
A compliant specification means nothing if the system isn't commissioned correctly. SBEM calculations assume controls work as designed — actual performance depends on proper setup, calibration, and documentation.
Systems that are difficult to adjust or expand will frustrate operators and may be bypassed. Specify controls that building management teams can understand and maintain.
[Part L Hotel Lighting Compliance Checklist]
We've prepared a practical checklist covering Part L lighting control requirements for hotel projects. Use it during design development to ensure all mandatory requirements are addressed.
The checklist covers:
Efficacy requirements by lighting type
Automatic control requirements by space
Daylight zone identification
Metering options
Documentation for Building Control
We support architects and M&E consultants with hotel lighting control specification
Early-stage consultation — Advise on control strategies that balance compliance, guest experience, and operational requirements.
System specification — Detailed specifications for Lutron and other lighting control systems suited to hotel applications.
Part L compliance guidance — Technical support for demonstrating Building Regulations compliance.
Commissioning and handover — Full system commissioning ensuring controls perform as specified.
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