At the 1979 RIBA Energy Conference, Nicholas Grimshaw talked about the benefits of mixed industrial and residential developments. Here, he takes his argument further and offers some worked examples.
This article was originally published in the RIBA Journal in October of 1980.
Among all the discussion about the most energy-saving ways of actually designing buildings, I think one subject has been particularly neglected. This is the question of the physical relationship between the living and working environment. 20th century planning has firmly kept all forms of industry separate from housing and indeed even the post-war new towns, although paying lip service to a mixed environment, still separate the functions into living zones and working zones. This is quite unnecessary bearing in mind the type of industry that is generally being provided for in the 1980s.
Heavy industry aside, the type of industrial buildings that are going up all over the country are approximately two stories high – the same height as most housing. They do not produce any noise or pollution and, provided traffic problems can be solved, and could easily be incorporated in many residential areas. High quality cladding materials are now being used by the better firms of architects and it has been commented that the facades of some recent industrial buildings look better than a lot of current public housing. Indeed, if brick and the tile claddings become phased out of housing projects due to the lack of skilled labour, facades made out of prefabricated elements now more commonly used on industrial buildings may well become the norm.
The concept that industrial buildings can be compatible with housing is even more acceptable if the idea that all industries are getting smaller and more efficient is fed into the equation. Many people feel that the prognosis for the future, at least in this country, is that that the most successful firms will be small, very well equipped, probably placed in a good environment in the countryside, and will carry on a lot of their communications by means of video screens and facsimile reproduction techniques.If one looks at Charles Eames' house in California and envisages this on a slightly bigger scale as a small high-tech company incorporating a good proportion of residential accommodation, then this might produce the image that I am suggesting.
In this article, I will try to set out some specific facts which support this argument and which have particular reference to energy.
Cost of travel: People working in a typical 8,000 sq m factory only need to live 2.2 miles away before the cost of the fuel they use for travelling to work will pay for heating the factory building throughout the year. Clearly, if they live an average of ten miles away then the fuel they use will heat the building five times over. This is by no means an unusual situation for a lot of typical industrial areas. Even if one of our most “modern” new towns – Milton Keynes — is taken as an example, where in theory it is possible for everyone to walk to work, it can be seen that virtually every factory is surrounded by cars on a typical day.
A further very important aspect to this question of driving to work is the capital cost of the cars themselves. If the average employee owns a car worth about £4,000, then the value of his car will almost exactly equal the value of the part of the building that he occupies. Thus the total value of the workers’ cars would equal the value of the building. This is a reasonable point to make since the cars cannot be used for anything else while they are in the works car park and the family may need a second car for shopping, taking the children to school, etc.
Energy exchange: Proximity of industry and housing would allow the same plant to be used for heating both if the plant was only slightly increased in size. Over a 24-hour cycle the main residential use of energy does not correspond with the main industrial use, and if the two curves are combined considerable economy will occur in capital cost of heating plant. If the housing and industry are so arranged that they are next to each other, the heat generated by the industrial process and lighting can actually provide background heating for housing to the extent that practically no plant need be provided at all for the housing.
Alternative fuel sources: As is widely known, British Gas has been phenomenally successful in laying a network of pipelines to supply virtually the whole country with natural gas in a very short period of time. However, it is not widely know that this network can only be used to about one third of its capacity because the system has to be designed to deal with the worst “cold snap” – a sudden drop in temperature – that might occur once in 20 years. Apparently, it is extremely dangerous if demand exceeds supply within the gas network. One answer to this problem would be to supply new industrial areas with natural gas and have alternative sources in the form of propane, oil or even coal, provided at their power house. If a cold snap occurred, the gas supply could then be automatically discontinued and the alternative source brought into play. The provision of, say, 28 days supply of alternative fuel on site would be a relatively low capital expenditure and could mean that the gas supply network could be used at up to two thirds of its capacity instead of one third as at present.
The design of buildings: An absolutely crucial factor in the design of all industrial buildings is the wall-to-floor ratio. Clearly, heat loss is a direct function of this and it is interesting to note that with a fairly large industrial building of, say, 8,000 sq m the cladding area is only 13.6 per cent of the total volume, assuming the building is 80m x 100m. Thus, the heat loss through the roof and the ground are much more important factors than the cladding itself, clearly. Therefore, the main point that needs attention is providing massive insulation to the roof of an industrial building. In this connection, it can be fairly easily shown that roof lights, apart from causing serious maintenance problems and potential leaks, are very difficult to justify in total energy terms.
As an example, a building with double-glazed rooflights making up 20 per cent of its roof area, the minimum really necessary to give any useful natural lighting, will use 204 kWhr/m²/pa (lights = 164, roof = 40) while an equivalent unglazed roof relying totally on artificial light will only use 193 kWhr/m²/pa (lights = 182, roof = 11).
Cladding: I firmly believe that a great deal of flexibility is needed. If a building is fitted with a weather-proof skin then the cost of adding insulation on the inside of this is a very small proportion of the total cladding cost, say 15 per cent. This is a cost which could reasonably fall on an individual user or could be given to him as an "allowance" allowing him to upgrade either the insulation or the finish of the interior itself. For a small lettable unit of Winnick Quay 4 in Warrington (RIBAJ January 1980), 26 double glazing panels at £30/m² and 12 Burgess ceiling tiles and insulation at £12/m² work out at £2,697 – just over the cost of a £7/m² carpet to fit out the equivalent area.
It must be appreciated that in any case, users' energy consumption varies widely. If industrial space is used purely for storage, then very little heating or lighting may be required. Indeed, a worker in a quilted suit with a miner's lamp could do without any lighting and heating at all! In my view, buildings should be designed to accommodate these needs and not incorporate massive heating and lighting installations from the outset.
Landscaping and Orientation: Shielding external faces of buildings with trees is an ideal alternative to any form of adjustable shading such as blinds or louvres. In summer the leaves provide shading from heavy solar gain and in winter when the trees are bare the building can benefit from the winter sunshine to cut down on heating load. Earth mounding can help to shield buildings from prevailing winds, and if suitable water-proofing treatments can be found, mounding against the walls of buildings can greatly help to stabilise temperatures.
Natural ventilation caused by the flow of air from the hot to the cold side of the building helps remove the layer of hot air which builds up under the roofs of industrial buildings in summer. In my view mechanical ventilation is very seldom justifiable in either industrial or housing environments.
In conclusion, I have tried to set out above some of the factors which I think are important from the point of view of energy in the total environment. I firmly believe that the proximity of living and working will prove a major energy-saving factor in the future. However, I do not believe that this would be successful on a massive scale.
I think the maxim "Small is Beautiful" will apply to all successful industries in the future, and this same idea applies equally well to any energy-saving schemes that might be produced. We have to be wary of massively high-tuned environments which are the result of the unthinking application of today's technology.
Acknowledgement: The calculations included in this article were supplied by Ronald Hurst Associates.