Much of the design of education, office and healthcare buildings in Britain is determined by the Building Regulations. There are now versions for England, Wales, Scotland and Northern Ireland, and although there are some core elements, each has its own nuances. Make sure you have the right guidance document for the location of the building.
When it comes to lighting, the focus is still on luminaire performance, with an option to include lighting controls factors. However, since the last iteration in 2013/14, Leni has been brought in as a way to measure actual performance – energy in use, rather than energy on paper. The industry supports this measure and we wait to see the changes in the 2016 edition.
Legislation governing the quantity of light is effectively restricted to that published by the Health and Safety Executive in HSG 38: Lighting at Work. As might be expected, it really only deals with health and safety aspects of lighting for people in the workplace rather than the creation of pleasant or appropriate lighting environments.
It says it is important that lighting in the workplace:
- allows people to notice hazards and assess risks;
- is suitable for the environment and the type of work (for example, it is not located against surfaces or materials that may be flammable);
- provides sufficient light (illuminance on the task);
- allows people to see properly and discriminate between colours to promote safety;
- does not cause glare, flicker or stroboscopic effects;
- avoids the effects of veiling reflections;
- does not result in excessive differences in illuminance within an area or between adjacent areas;
- is suitable to meet the special needs of individuals;
- does not pose a health and safety risk itself;
- is suitably positioned so it may be properly maintained or replaced, and disposed of to ensure safety; and
- includes, when necessary, suitable and safe emergency lighting.
HSG38 also gives recommended illuminance levels although these are only split into five categories dependent on risk and level of detail with average illuminances ranging from 20 lux for circulation areas to 500 lux in drawing offices. It also sets out the minimum levels deemed acceptable. Given the limited scope of the categories, it is better to obtain more detailed guidance.
The Society of Light & Lighting (SLL) publishes a raft of lighting guidance which reflects the relevant European Standards. The guidance covers not just recommended illuminance levels for tasks, but also application guidance.
The SLL Code for Lighting (2012) is seen as the bible because it covers all the technical aspects of the application of light, including the all-important numbers. It does explain that the numbers are not sacrosanct, but this is often overlooked in specifications that stick to the numbers without considering the design or needs of the people working in the building.
In the SLL Lighting Handbook, there are chapters that cover the main design elements for each application but more crucially, SLL also publishes detailed application guides, so LG2 (hospitals and healthcare, LG5 (education) and LG7 (office) are must-reads for anyone looking to design these spaces. LG7 replaced LG3 (display screens) a number of years ago and I understand there’s a brand new, LG7 weaving its way through the printers’ presses right now, so keep an eye out for that in a few months.
Daylight is – or should be – a key component of the design of any of these building types, so a browse of the recently published LG10 on designing for daylight should assist the design team, especially the architectural team.
The most often overlooked guidance, especially in healthcare but also for centres of learning, is that which covers the importance of surface reflectance and colour. It might seem out of the remit of the lighting team but the use of different colours – or even colour temperatures – can be a key deliverer for way finding and orientation. This is especially the case when considering the elderly or those with limited capacity to store information such as those suffering from dementia. We can associate colour or contrast with familiar things or alerts such as danger and this should be part of the overall design.
Esos affects any company or organisation with 250 employees or with a turnover in excess of €50 million. If a company qualifies for Esos and is not fully covered by ISO 50001 it will have to carry out an Esos assessment by 5 December 2015.
This will probably affect all universities as well as many companies with offices and probably some hospitals – the public sector is excluded but any privately owned estates will have to complete their audit.
LG7 calls for relative illuminance to be delivered on the ceiling and walls to create a pleasant working environment. In the most recent version of EN14264:1, discrete values were added for this – at a much lower level than the 50 per cent on walls and 30 per cent on ceilings that the SLL recommends. The SLL recommendation is still for 30 and 50 per cent and not the discrete values. We didn’t like working in ‘cave lighting’ in the 1980s, and there’s no reason to go back to it now.
The overriding purpose of documents such as LG7 is to create pleasant environments for people to work in, not to make things tricky for manufacturers. But we must still adhere to glare ratings and consider how luminaires will look in the environment they’re placed, not just architecturally but for the people who will have to spend up to 10 hours a day in that room. The guidance is there to help, not hinder.