Home working lighting experience (initial review)
Andrew BissellView bio
Working from home brings its challenges but it also brings an opportunity to learn more about ourselves and what our natural preferences and working habits may be. The initial findings below come from a ‘home working lighting experience’ survey the staff at Cundall were asked to complete.
Due to the typical differences between people’s homes and their offices such as smaller rooms compared to large open plan; more rural locations rather than city centre locations; more personal control compared to office wide automatic control etc. some results came back as expected e.g. people were typically sat a lot closer to a window and used very little electric light through the working day. Whilst we have not yet measured the daylight or electric lighting levels in peoples homes, we can say with a high degree of certainty that the closer access to daylight is positive for their health and wellbeing, whilst their lack of need for electric light is reducing energy consumption.
Access to Daylight
Figure 1: The distance people are sat from a daylit window.
Figure 1 above shows that from the responses to date, 75% of our staff are sat within 2m of a daylit window and just over 85% of our staff are sat within 3m of a daylit window. This is very positive with respect to health and wellbeing. Based on the above we have some further tasks to undertake :
- Review the responses where people were more than 3m from a window and especially where people were more than 5m from a window. Understand if changes need to be made or can be made.
- Interrogate the data to compare what people experience now compared to their office experience.
- Select individuals to take readings of their daylight and electric lighting along with external light levels.
Orientation of Workstation
Figure 2: Which way people face in relation to the daylit window
Nearly 60% of the respondents sit at 90 degrees to the daylit window. This is excellent and in line with the WELL criteria. This orientation allows the daylight to arrive at the eye which is beneficial for our circadian rhythm whilst reducing glare from the sky and reflections on the screen. However we now need to understand a little more about the 40% of respondents. Some of this will come from further analysis of the data and some will come from questions to selected individuals.
- Of those facing the window what is the view, i.e. is it a south facing bright sky or a building?
- How big is the window, what type of blinds does it have?
- Of those facing away from a window, why? Is it a limitation of the space and furniture?
- Would new furniture enable a change?
Quality of View
Figure 3: Predominant objects viewed through the window.
A series of questions were asked to establish how much of the respondent’s view was made up of buildings, nature or the sky. There is a lot to data to review in the responses we received but some of the headlines include :
- 30% of respondents predominantly looked at other buildings from their home working position. (We considered that predominant would be more than 50% of the view). i.e. More than 50% of the view are buildings.
- 70% of respondents predominantly looked at nature and the sky from their home working position.
The data will now be reviewed to see how closely the view of buildings relate to those who live in city centre locations compared to more rural areas. A further review will also look at the quality of the view of buildings as it is not appropriate to simply say a view of buildings is a bad thing. However if the view is say another apartment block or a car park and maybe just 10m away, then perhaps the judgement on the quality of the view would be different.
Figure 4: Hours of use of electric lighting
Unsurprisingly, given how much access people have to daylight, the use of electric lighting is very low. Nearly 50% of respondents are using no electric light at all through the working day. A further review of the data is needed to establish if the 8 hours of lighting is related to the distance from the window, the orientation to the window or perhaps just a preference to have more light.
We also asked staff for their ideas and thoughts on lighting their home working environment. The responses addressed several areas, two of which are discussed below.
Electric Lighting Preference: There is a preference for task lighting rather than overhead general lighting and where overhead lighting is mentioned the preference is for indirect lighting. When you consider the number of offices where the floor plate is littered with recessed overhead lights then the responses here are at odds with how many offices are lit.
Choice of Desks: Several responses discussed how you could move your working position to follow the sun or follow the view of the sun. Also there was a mention of moving your working position to suit your tasks, e.g. focused work is done in the spare room where the desk is set up whilst less focused say phone calls are done on the sofa or outside in the garden.
What the responses show to date is that where people can make a change they tend to do so. In many ways this is where we are heading with workplace design anyway. People are starting to have a variety of types of spaces where they can work rather than a fixed position which is a standard desk and chair. Will employers have to offer more of this variety to make the office feel more like the home?
Measuring Lighting Levels and Quality
As mentioned earlier it is great to see that most people have enough natural light to not need any electric light. From the responses we can see that people are providing their preference of electric lighting when it is needed. Some of the responses show a preference for tunable white lights, mostly for tasks lights and some for indirect lighting. At this stage however, what we do not know is the quantity and quality of light which people working at home are experiencing and this will form a follow up survey with selected respondents.
At my own home working position I have recorded natural lighting levels from 400 Lux to 2000 Lux whilst my electric lighting provides just 120 Lux at 2700 Kelvin which I find ample for computer based tasks. (That is not to say it is ample in the long term). At this moment in time I am currently receiving 1002 Lux at 6228 Kelvin vertically at my eye. Comparing that to the WELL™ Feature 54 ‘Circadian Lighting Design’ then we are passing with flying colours. Essentially what most of us are now experiencing at home is ‘adaptive lighting comfort’. We have daylight quality and intensity for most of the day but we then have a much lower intensity of light at a much warmer colour in the evening. This is very different to current office lighting where there may be some form of colour tuning but there would still be a lot of light (400 or 500 Lux) in late afternoon and evening.
Figure 5: (Left) Spectral Distribution of Daylight recorded at 12:56 Monday 13th April. (Right) Cool White LED
Conclusions should not be drawn from the above as this is a snapshot in time and the same and more questions need to asked again when people have worked from home for a longer period of time.