Get Sust! Issue 25

COMMENT

Depressed? You soon will be... Get Sust sheds a little light on the Code for Sustainable Homes.

Well, January is a dark and gloomy month, and the post-holiday blues can sometimes strike. But here in the Get Sust office, we’re not feeling depressed; we’ve been too busy reading a new book by Richard Hobday on the vital role that access to daylight plays in keeping us all healthy. (“Depressed? You soon will be” is the title of Chapter 3.)

The book arrived at an opportune moment. For work-related purposes, I’ve been reading up about the cleanliness (or otherwise) of hospitals; I’ve also been getting to grips with the recently published Code for Sustainable Homes. And, as a home-worker, I’ve been doing all this while listening to a short series on Radio 4 called (unimaginatively) “Working from Home”.

Apparently some 3 million people already work from home (teleworking); and the government (and business) wants to encourage this, for all sorts of reasons, not least because it cuts down on commuting-related carbon emissions.

And so I wondered what the new Code for Sustainable Homes has to say about provisions for home-workers. The detailed descriptions of requirements do mention “provision of a space and services which allows the occupants to set up a home office in a quiet room” in Category 1 (Energy/CO2), but only offers 1.2 points for this. (A dwelling needs 36 points to gain 1 star; and 90 points to achieve 6 stars - a zero-carbon home.)

So, a workplace in the home is a plus; but what about lighting it? Well, according to Richard Hobday’s book, a person spending 8 hours outside (where typical light level would be 10,000 lux), would be exposed to 80,000 lux. But these days people spend 90 percent of their time indoors, so the same person working indoors in, typically, 250 lux for 8 hours receives just 2000 lux hours of light - a staggering difference.

Sustainable office design tends to pay careful attention to daylighting - good levels can reduce the buildings energy consumption; too much daylight can require shading, or result in overheating.

General offices should aim for a daylight factor (DF) of 2%; areas where typing and computing is done aim for a DF of around 4%; and a typical architect’s drawing board should have a DF of 6%. (The daylight factor compares illuminance at a reference point in the building with the illuminance at that same point if the building was not in the way.)

Unfortunately the Code for Sustainable Homes does not pay much attention to daylighting; either for home offices or the rest of the dwelling.

The provision of daylight is in the Health Category (OK, so we’ll give them a bonus point for that!). But only a measly 4 points are available. To gain these four points (Category 7), designers must ensure that:

kitchens achieve minimum average DF of at least 2%
living rooms, dining rooms and studies to achieve a minimum average DF of at least 1.5%
kitchens, living rooms, dining rooms and studies to be designed to have a view of the sky.

The Code gives three “case studies” of how homes might achieve a 1-star, 3-star and 6-star rating. Daylighting only gets a mention in the 6-star example (and then, almost as an after-thought).

This is a missed opportunity in so many ways. Hobday’s research in the 1980s found that “well-designed solar dwellings typically use 25 to 50 per cent less heating and light energy than comparable non-solar buildings”. This is important for homeworkers, but there is also a tendency to forget that there are plenty of other people who are at home throughout the day - the elderly, the infirm, parents and children, and people who do not work. All of these would benefit from getting more daylight into their homes, particularly those who don’t or can’t get out much under their own steam.

Interestingly, Richard Hobday explains how for centuries people had understood the health benefits of daylight, but in the 1970s scientific opinion shifted - partly because of a (mis-placed) belief that antibiotics and vaccinations could cure most common illnesses; but coincidentally because of the dangers of excessive exposure to the sun (because of the risk of skin cancer). The idea of designing buildings for daylight fell out of fashion, and its only recently that researchers have begun to re-visit the health benefits, amid scares about MRSA, concern over the ‘unrecognised epidemic’ of vitamin D deficiency, and a seemingly unstoppable growth in depression - which is surprising closely linked to daylight.

Designing for daylight is not easy. Hobday’s book explains how, and why, some of the 20th century’s greatest architects designed for the sun.

Anyone involved in designing the next generation of buildings should read this book - whether or not they are aiming to achieve a Star Rating. After all, sustainability is not solely about carbon emissions - if it was, we’d all live in underground bunkers. Opening the curtains each morning and letting the sun shine in is a simple human pleasure - but it’s well worth it.

Learn more:

	•	The light revolution; health, architecture and the sun, by Richard Hobday PhD; Findhorn Press www.findhornpress.com E-mail: info@findhornpress.com. ISBN: 978-1-84409-087-7. Price: £9.99.
	•	For a general overview of daylight factors, see www.learn.londonmet.ac.uk.
	•	The Code for Sustainable Homes (England and Wales only) is on the Planning Portal website at www.planningportal.gov.uk (choose “professionals” > “policy and research”). From April 2007 all publicly funded housing developments will need to achieve a three-star rating. Detailed technical guidance for the Code will be issued in April 2007.
	•	Working from Home, BBC Radio4.