WELL and BREEAM are building certification schemes that assess how spaces affect human health and environmental sustainability. Both have become influential benchmarks for commercial office projects across the UK, particularly in CAT A and CAT B fit-outs where clients expect evidence-based design decisions.
The WELL Building Standard, developed by the International WELL Building Institute (IWBI), evaluates factors that directly affect occupant health. Lighting sits at the heart of this standard. BREEAM (Building Research Establishment Environmental Assessment Method) originated in the UK and takes a broader environmental view, though its Health and Wellbeing category includes specific lighting criteria.
For architects, lighting designers, and electrical engineers working on UK commercial schemes, understanding where these standards overlap—and where they differ—helps you specify lighting that achieves multiple certifications without duplicating effort or cost.
WELL v2 dedicates an entire concept to light, recognising that quality illumination affects circadian rhythms, mood, and cognitive performance. The standard includes both preconditions (required features) and optimisations (optional credits).
Feature L01: Light Exposure requires projects to demonstrate adequate daylight access or achieve circadian lighting design thresholds. Feature L02: Visual Lighting Design sets illuminance targets aligned with recognised standards such as CIBSE SLL Code for Lighting or EN 12464-1.
The standard also addresses glare control (L04), electric light quality (L07), and occupant control (L09). Each feature builds toward an environment where lighting supports biological needs rather than merely meeting minimum functional requirements.
Feature L03: Circadian Lighting Design is where WELL differentiates itself from most building standards. Rather than measuring light in lux alone, WELL uses Equivalent Melanopic Lux (EML), which accounts for how light affects the melanopsin photoreceptors in our eyes that regulate our internal body clock.
For workstations used during daytime hours, WELL requires electric lighting to achieve specific EML thresholds—typically 240 EML or higher during morning hours, measured at the vertical plane at eye level. This metric ensures that artificial lighting can support alertness when daylight is insufficient.
Meeting these requirements often involves specifying luminaires with higher colour temperatures during working hours and selecting products with appropriate spectral power distribution. 299 Lighting works alongside architects and consultants to identify fittings that balance circadian performance with visual comfort and energy efficiency.
BREEAM's lighting requirements fall primarily under the Health and Wellbeing category, specifically Hea 01: Visual Comfort. This credit assesses daylighting, view out, glare control, and internal lighting levels.
The daylighting criteria evaluate whether occupied spaces receive adequate natural light, measured using methodologies described in BREEAM Guidance Note 50. Projects can demonstrate compliance through climate-based daylight modelling or by meeting spatial daylight autonomy targets.
For electric lighting, BREEAM references industry standards including CIBSE LG7 for offices. Luminaires must meet Unified Glare Rating (UGR) limits—typically UGR 19 or lower for general office areas—to minimise visual discomfort. At 299 Lighting, we have delivered over 2,000 commercial projects where LG7 compliance and glare analysis formed core specification requirements.
Both standards value daylighting, glare control, and appropriate electric lighting levels. A project targeting both certifications can often address multiple credits with the same design strategies.
For example, specifying luminaires with UGR 19 or lower satisfies WELL's Feature L04 (Electric Light Glare Control) and contributes toward BREEAM's Hea 01 glare criteria. Similarly, maximising daylight exposure supports WELL's L01 and L05 features while contributing to BREEAM's daylighting credits.
Where the standards diverge is in their treatment of circadian health. BREEAM does not currently include specific EML or circadian lighting requirements. Projects pursuing both certifications therefore need to layer WELL's circadian criteria onto the BREEAM baseline.
Selecting the right luminaires early in the design process reduces the risk of costly specification changes later. Several product characteristics support both WELL and BREEAM compliance.
Colour rendering matters for both standards. WELL's Feature L07 requires CRI 90 or higher (or CRI 80+ with R9 above 50). High CRI luminaires render colours accurately, reducing visual strain and supporting task performance. Our linear lighting range includes LG7-compliant options with CRI 90+ that meet these thresholds.
Flicker management is another shared concern. WELL specifies maximum flicker frequency (90 Hz minimum) or low flicker percentage. Quality LED drivers with high-frequency operation address this requirement while improving visual comfort for VDU-intensive work.
Tunable white lighting enables projects to adjust colour temperature throughout the day, supporting WELL's circadian objectives while maintaining visual consistency. 299 Lighting integrates Casambi wireless controls into our luminaires, enabling scene scheduling and colour temperature adjustment without complex wiring infrastructure.
Both WELL and BREEAM reward intelligent lighting control strategies, though for different reasons. WELL's Feature L09 addresses occupant control, requiring that individuals can adjust their immediate lighting environment. BREEAM credits energy-efficient control strategies that reduce operational carbon.
Automated dimming based on daylight availability supports both objectives. Occupancy sensing prevents energy waste in unoccupied areas while ensuring lights respond to actual use patterns. Personal control apps—like those available through our Casambi integration—allow occupants to customise light levels from their phones.
For circadian lighting strategies, time-based controls can shift colour temperature throughout the day. Cooler, higher-EML light during morning hours transitions to warmer tones in the afternoon, mimicking the natural progression of daylight and supporting healthy sleep patterns.
When your project targets both WELL and BREEAM, coordinate lighting specification with your sustainability consultant and WELL Accredited Professional early. Mapping credit requirements against your luminaire schedule identifies where single products can satisfy multiple criteria.
Request photometric data, spectral power distribution curves, and flicker test reports from your lighting supplier. These documents demonstrate compliance during assessment and verification stages. All 299 Lighting products are supported with LDT files, spacing information, and technical data sheets that simplify this process.
Consider commissioning and post-occupancy requirements as well. BREEAM may require lighting measurement surveys, while WELL performance verification tests actual EML levels in occupied spaces. Specifying for the target values—rather than the minimum thresholds—builds in headroom for site conditions that differ from design calculations.
WELL and BREEAM both recognise that lighting affects occupant health, comfort, and productivity. WELL's focus on circadian health and individual control complements BREEAM's emphasis on daylighting, glare management, and energy efficiency. Together, they create a framework for office lighting that goes beyond compliance toward genuine wellbeing outcomes.
Working alongside architects, consultants, and contractors, 299 Lighting delivers fully engineered lighting schemes that address both certification pathways. From LG7-compliant linear systems to Casambi-enabled controls, we can take you through all your options to suit your timeline and budget.
Want to know more about what 299 Lighting can do for your project? We are the Light Engineers.
Equivalent Melanopic Lux measures how light affects the melanopsin photoreceptors in your eyes that regulate circadian rhythms. Unlike standard lux, which measures brightness for visual tasks, EML accounts for the spectral composition of light and its biological impact. WELL v2 uses EML thresholds to ensure electric lighting supports alertness during working hours.
Not necessarily—they serve different purposes. BREEAM is often required by planning conditions or landlord specifications in the UK. WELL is typically client-driven, selected by occupiers who want evidence-based wellbeing outcomes. Many projects now pursue both, recognising that they address complementary aspects of building performance. 299 Lighting supports projects targeting either or both certifications.
Both standards reference UGR 19 or lower for general office lighting, aligning with CIBSE LG7 recommendations. This rating minimises glare discomfort for occupants working at VDU screens. 299 Lighting specifies luminaires with verified UGR ratings and can supply glare analysis calculations for your lighting scheme.
Yes, though retrofit projects may require luminaire upgrades and control system modifications. WELL offers a pathway for existing buildings, and BREEAM In-Use assesses operational buildings. Replacing older fittings with high-CRI, low-glare LED luminaires often delivers immediate improvements. 299 Lighting offers lighting surveys to assess current conditions and identify upgrade opportunities.
Tunable white fittings adjust colour temperature between warm and cool settings, enabling you to deliver higher EML during morning hours and warmer tones later in the day. This supports WELL's circadian lighting requirements by mimicking natural daylight patterns. 299 Lighting integrates tunable white capability with Casambi controls for straightforward scene scheduling and occupant override.