Jonathan Dore, Commercial Director at Kingspan Light + Air, sheds light on the benefits of balancing natural and artificial lighting in the design of a workplace
In modern architectural design, building natural lighting into projects is becoming a key consideration due to its health and safety benefits for occupants and additional energy-saving prospects. But with LED lighting becoming the lighting of choice due to its energy efficiency, striking the balance between natural and artificial lighting from design stage is needed to ensure a compliant and comfortable working environment for staff which embraces overall energy-saving potentials.
Referring to the deliberate placement of windows, skylights and other openings, daylighting’s main ambition is to help a facility to maximise natural lighting as much as possible with measurable benefits.
With any system specification, building regulations are a natural focal point. For facilities managers, ensuring that a building meets the needs of the people working in them as well as operational requirements is essential. Part L has helped to bring U-values in relation to energy efficiency and thermal performance into the spotlight, but in terms of daylighting it’s not always as clear.
BREEAM UK New Construction 2018 considers the provision of daylight into a building. BREEAM emphasises that achieving 300 lux of natural light for 2,000 hours of the year will help with the overall sustainability of the facility. Adhering to these recommended standards can help to reduce reliance on artificial lighting and ensure workers’ visual comfort levels are appropriately managed. Considering this, the WELL standard, which is intended to improve the quality of indoor spaces, highlights the benefits of natural lighting and appropriate artificial lighting in terms of attainment, productivity and the promotion of health and wellbeing for employees.
BLENDING THE DESIGN
From productivity to improved wellbeing and happier staff, daylighting benefits people, and with this comes the reduced need for artificial lighting, ultimately leading to cost-saving benefits.
From proposal stage, natural lighting can be built into the design framework, blended with artificial lighting solutions to meet appropriate lighting levels for workers. Complying with the recommended European daylight standard BS EN 17037, which advises that the minimum level of 300 lux should be exceeded for all the space within the building and half the daylight hours of the year, can help to ensure a safe, comfortable working practice which benefits occupants.
The factors that must be considered are the U-values, solar heat gain coefficient (G-value), visible light transmission and diffusion. Determining heat loss, heat gain, how much light will be transmitted, and the distribution of light and glare all have an impact on the internal working environment. From initial design stage the lux level should drive the initial process, but these other factors are important as they can impact the thermal performance of the building and how well the natural lighting solution will spread light into the workspace.
By utilising building energy modelling, the exact profiling of natural lighting solutions can be identified in detail, determining the impact on energy consumption and the exact levels of daylighting that can be achieved.
As well as maximising potential for natural daylighting, blending artificial LED into the process with daylight harvesting and occupancy controls can lead to significant savings in cost and energy consumption.
No electric light, even high-quality LEDs, can entirely replicate the frequency of natural light or achieve variations received at different times of the day. Modern LEDs are a significant improvement, but daylighting’s colour rendition is the best for workers. With this in mind, a blended solution of high-quality LEDs with daylight harvesting functions that will sense the amount of natural light, and the implementation of natural daylighting solutions such as rooflights and wall lights, can help to seamlessly ensure an environment’s comfort levels, helping occupants to reap the natural benefits of daylighting and improving building efficiency.
Understanding and applying the benefits of natural daylighting, effectively balanced with sophisticated LED technology, has the potential to transform the working environment – but solutions should be carefully chosen and managed to withstand the test of time. Regular maintenance and reviews will ensure the products are working as expected, that the staff are actively gaining the wellbeing benefits, and that the building is performing as expected from a thermal perspective.