Office lighting: Should we even be calling it ‘the office’?
Workplace interiors started changing BC (before Covid). Fast-forward to 2024, and they have prompted a paradigm shift. Sophie Parry CEng MIET FSLL, Head of the UK Academy at TRILUX, discusses this shift and what constitutes good lighting for today’s working environments.
Controlled architecture has given way to softer design, blending hard surfaces with a more inclusive, refreshed environment to encourage a return to the office. From an interior design perspective, workplaces need to be functional and visually appealing, support a Net Zero future, and enhance wellness, neurodiversity, creativity and productivity.
Cat A, Cat A+ or Cat B vs. sustainable best practice
Is creating a Cat A workplace without knowing the tenant a good idea? Often, the outcome is a neutral solution that may either deter tenants due to modification costs or the Cat A lighting installation is not adequate, and the ceiling-mounted luminaires are removed and scrapped, subject to a significant Cat B fit-out.
Cat A+, such as fully serviced office space, works for some businesses but not the majority of medium-to-large companies. Cat B fit-outs are the only realistic way for a tenant to achieve a correctly lit space compatible with their business needs that complements the interior design and supports wellness, neurodiversity, creativity and productivity.
What if a compromise provided a sustainable lighting solution for both Cat A & Cat B?
The current and growing industry trend is to fit a lighting trunking matrix based backbone as a constant at Cat A and then add the required number of plug-and- play luminaires and lighting devices for tenant viewings and space maintenance.
During the Cat B fit-out, the tenant and their lighting designer work from the existing lighting trunking matrix, repositioning and adding luminaires and lighting devices to complete an appropriate lighting installation for the business. This method should also reduce/eliminate lighting waste in the transition from Cat A to Cat B.
Wellness and neurodiversity
One key requirement of good lighting design is to ensure that the light is appropriate for the space and task and that, subject to the project budget, the lighting quality aims to replicate as far as possible the purest form of light daylight.
In the indoor environment, we can’t always benefit from copious daylight, so electric lighting will often need to be able to deliver the complete lighting requirement for the space.
The electric light will need to be both energy efficient and deliver a quality of light supporting wellness and neurodiverse staff.
The key quality elements required are:
Adequate but not excessive illumination. Lighting that provides the required level of illumination and uses a minimal amount of energy. Excessive illumination also potentially introduces discomfort glare.
Discomfort glare management. Careful luminaire selection and design modelling can help reduce the potential for discomfort glare.
Orientation and shielding of the LED light source within the luminaire. Just being able to see the light source can be problematic. Consider indirect lighting or luminaires with suitable quality diffusers or optics.
Reduction of light and shadow through good uniformity. Reducing the number of luminaires may save money and energy, but the variance between light and shadow between luminaire spacing will become more noticeable and can be disconcerting to space users who are unlucky enough to be seated in the shadows.
Reduced levels of flicker and stroboscopic effects. This insidious side effect of poor quality lighting can introduce eye strain and migraines.
Appropriate correlated colour temperature. In northern Europe, the preference is typically 4000K. +/-1000K is broadly acceptable, but anything outside of these parameters will likely adversely impact the space user’s perception.
Melanopic light levels. Melanopic light, found in daylight, helps recalibrate our body clocks, regulates hormones and body temperature and is associated with wellness. LED luminaires can replicate this natural recalibration.
Biophilia
As part of the increased awareness of wellness, biophilic installations in the workspace are growing and are typically based on living ornamental plants. Ideally, the biophilic installation will benefit from the required levels of daylight. Often, this is not the case, and the electric lighting installation is expected to meet this condition.
This expectation is more complex than it may seem. Plants require a different quality of light than humans, so just assuming the overhead lighting will be adequate will not provide the solution. Plants need higher levels and a different spectral power optimisation of light than humans, as well as UV and infrared, which are deliberately engineered out of general-purpose LED light sources used for human-centric applications.
That said, LED light sources are available with optimised spectral power distribution characteristics that support indoor decorative plants. The luminaire quantity, type and mounting position are separate from general workplace lighting and dedicated to biophilic installation.
Luminaires and acoustics
Noise pollution is detrimental to wellbeing and, therefore, productivity. Acoustic ceiling-mounted or hung baffles are installed to solve this problem, but coincidentally, in the same ideal position for the luminaires. The acoustic panels need to have a calculated surface area to be effective, so where should the luminaires be placed? The perfect solution is to integrate recessed luminaires into the acoustic baffles.
Lighting and intelligent buildings
A typical lighting installation also comprises a control network. Given that lighting is required in all areas of a space or building, a wealth of data is available for historical and real-time information and, in some systems, machine learning to optimise the efficiency of the lighting installation. This data can also be shared with other building systems and services.
Typical benefits include:
- Historic data on space occupancy
- Raising and lowering HVAC setpoints on space occupancy
- Temperature and humidity monitoring
- A higher granularity of lighting control for the space user
- Automatic testing and monitoring of emergency lighting systems
- Automatic control of window shading systems
- Lighting energy monitoring and reporting
Future trends
In terms of energy efficiency, LED light sources have become the default technology over the last decade. In the future, we should see more emphasis on lighting quality to enhance the space user experience. There is also a growing demand from the intelligent building community for increasing amounts of data to inform decision-making and to enable algorithms to make progressive optimisations based on feedback data to the lighting installation quality and energy efficiency. And finally, as we advance, lighting will have to make a proportionate but increasing contribution to Net Zero.
