Verity Bird
Posted: Monday, May 17, 2010 11:05 am

The first of these articles (Sustainability – Great buzz word but why do it?) ended with the suggestion that genuine sustainability starts with good design.  Here we discuss in greater depth what is meant by this and what this series of articles is really about.

Over the last five years or so the sustainability agenda has moved from being something of a fringe concern, the preserve of hand-knitted, leather sandaled eco-types, to a mainstream issue at the heart of government policy (where this is not pulling in the opposite direction), especially in relation to developments in the Building Regulations.  This has raised the issue in the public consciousness so it has been picked up on by marketing people as a means for selling goods.  Adding ‘eco-‘ or ‘environmentally friendly’ or simply putting more of the colour green into the packaging is a means, purely and simply, of selling us more ‘stuff’.  There’s no obligation to actually make the goods any less damaging than they were before.  This is what is meant by greenwash.

The great supermarket carrier bag swindle is an example of this.  As a household of five we typically throw away two bin-bags of rubbish a week.  Because we recycle paper and glass, food waste goes separately to the council’s anaerobic digester and veg waste onto the compost, almost the entire contents of our two bin bags is packaging, mostly from food.  If we threw away carrier bags, rather than re-using them, the effect on the bulk of our rubbish would be negligible.  Yet supermarkets trumpet their reduced use of carrier bags without addressing the bulk of the rubbish they produce (all that plastic packaging) one iota; nor do they do anything to address the huge issue of food miles vs local production.  Greenwash!

So what about ‘eco-bling’?  When the ‘s’ word is mentioned in relation to design and development it is frequently accompanied by a sharp intake of breath and muttering about the excessively high extra cost of sustainable design.  The first thing that springs to the minds of many people are the expensive add-on goodies, often related to the production of renewable energy; wind-turbines, solar panels (thermal and photovoltaic), heat pumps and so on.  Effective systems are undoubtedly costly; inevitably at the moment as the market for much of them is, relatively speaking, in its infancy and we are used to having as much energy as we want, relatively cheaply, from traditional sources.

Yet these systems are only the outward show of sustainable development.  If they are not embedded into a holistic consideration of the complete design then they are nothing but a bit of ‘bling’ to provide an eco-veneer to an otherwise ordinary scheme.  While somewhat better than greenwash in that at least the energy generated is from renewable sources (but only if appropriately sited), this still falls a long way short of genuine sustainability.  As with greenwash, there is a likelihood that eco-bling alone will adversely affect the public perception of sustainable development because it will rightly be perceived as very costly in relation to the benefits that accrue.

So where does sustainability really start?  From the start of the site appraisal we can begin to look for the opportunities inherent in the piece of land or the building we are working on.  There is an abundant source of free heating available, in some form, to virtually all sites – the sun.  It does not take anything more high-tech than a window to begin to exploit that resource (of this a lot more detail in future columns).  By embedding an intelligent and thoughtful approach into our design thinking, we can make the most of available free energy at zero or negative extra cost to our clients or the planet.  Win-win.

The next step has to be to consider how we can capture and hold the energy thus gained – this will often be heat energy in the UK climate, but ‘coolth’ (actually the ability of materials to absorb excess heat) also comes into consideration here.  There are two ways that energy is lost.  Conduction through the building fabric is simply and inexpensively addressed by the unromantic and low-tech solution of increasing levels of insulation.  Clearly there is an energy balance to consider here in that each extra 50mm of insulation added will save less than the 50mm before it until you get to a point where it costs more energy to produce than it will save.

The second major route for heat loss is uncontrolled ventilation; this is where airtightness begins to become important.  There is frequently an additional cost associated with airtightness, especially in relation to timber frame construction on the mainland UK due to workmanship issues on site.  Yet interestingly, one of our students, who is based the Isle of Wight, wrote a dissertation looking into airtightness a couple of years ago.  She found that timber frame, which accounts for roughly 75% of new build on the island (compared to about 25% in the UK as a whole) came out just as well in airtightness tests as traditional methods of construction, typically showing somewhat under half the leakage allowed in the Building Regulations.  The most likely reason being simply that island builders are familiar with the workmanship issues relating to achieving airtight timber-framed buildings.

All of these issues will be explored in greater depth over coming weeks.

It is only after the passive capture of free energy and the minimisation of energy losses have been incorporated into a design, that it becomes worth considering how to provide the remaining energy requirements of the development from alternative sources.  Because less energy will be needed to run the building all systems, whether traditional (e.g. gas boilers) or renewable (e.g. solar thermal/PV), can be smaller.  Cyril Sweett’s excellent analysis from 2005, ‘Putting a Price on Sustainability’³, showed that achieving reasonable levels of sustainability will often actually cost less than straightforward traditional construction as this graph taken from his figures demonstrates: 

Once you begin to consider going truly zero carbon – assuming you can arrive at a clear definition – there will be an on-cost (though not nearly as much as some of the scare-mongers would have us believe), however this should be set against economy in relation to running costs.

The key issue is that to achieve a genuinely sustainable design you need to approach it from a whole-building perspective.  Considering siting/orientation, internal layout (user need) and fenestration, materials and servicing in a holistic manner – as the best designers always have, design can be innovative, creative and sustainable. 

References/further reading:

1. http://image.made-in-china.com/2f0j00HCvtDITKuEuz/Plastic-Carrier-Bag-T-Shirt-Bag-On-Roll-Bag.jpg
2. www.telegraph.co.uk/news/uknews/1547012/Green-Cameron-forced-to-remove-turbine.html 
3. Sweett C; 2005; Putting a Price on Sustainability; BRE Trust

Verity Bird

Verity Bird has been a Senior Lecturer in Architecture and Interior Design at Southampton Solent University. The bulk of her career, after several years in private practice in the 1980s, was with City of Bradford’s Architects department where she rose from project architect to group leader level.  Verity has been interested in environmental issues for many years and was involved in the Agenda 21 group in Bradford, speaking at local conferences into sustainability and energy use minimisation during the 1990s.  After leaving Bradford she worked in the Estates and Facilities service of Southampton University for a short period before moving into academia at Solent.