John Miles is a mechanical engineer with a professional background in the design and development of high-performance structures to withstand impact, blast, earthquake, and other types of extreme event.

His more recent experience has been in the field of design for manufacture and he has been responsible for the developments of novel factory-built systems for the construction of housing and other residential buildings.

John is a Main Board Director of Arup Group, a Director of The Housing Forum and a CABE Commissioner.

1. Homing in on Excellence - a commentary on the use of offsite fabrication methods for the UK housebuilding industry, The Housing Forum, London, 2002, page 45.

2. John Miles, a Main Board Director of Arup Group, a Director of The Housing Forum, and a commissioner for CABE, speaking at The Pre-Fabulous Home.

3. John Miles, speaking.

4. John Miles, speaking.

5. Homing in on Excellence, page 15.

The Pre-Fabulous Home

The Building Centre was packed for a half day seminar on the insightful report from The Housing Forum, Homing in on Excellence - a commentary on the use of offsite fabrication methods for the UK housebuilding industry. Download it here. Titled The Pre-Fabulous Home, The Building Centre Trust collaborated with The Housing Forum and Design for Homes to argue '… why every designer has to start rethinking house building'.

Under the tight chairmanship of Robert Bevan, editor of Building Design, it was clear from both the speakers and the audience that engaged designers are not the individuals who need too much convincing about how pre-fabrication might increase efficiency, cut costs, reduce wastage, increase collaboration, and exploit the evident innovations being promoted by pioneers in the construction industry. As a Board Director of Arup Group, a Director of The Housing Forum, and a commissioner for CABE, the keynote speaker John Miles immediately identified that the parties who need convincing are those being asked to risk their capital in transforming house building into a manufacturing industry.

'New products will not appear without high capital investment. Innovation can be costly, and so long as there goes on being relatively little sharing of research and development costs between manufacturers and suppliers, it will continue to be difficult to recoup initial investment. In the current climate, bespoke products are often a design requirement, undermining the affordability that can be ensured by moving towards ranges of standardised products and systems. Product availability will accelerate when house designs are tailored to the requirements of manufacturing processes.' (1)

The message is that designers need to be subsumed into a capitalised manufacturing industry. The understandable and welcome popular demand for design must be rescued from the popular illusion - and a favourite amongst architects it must be said - that homes are uniquely designed works of artistic endeavour. Choice is good for Miles, but he wanted to understand how choice and quality can be affordably realised.

Miles asked '… do you ever think about how things are made?' (2) The designers in the room warmed to his insistence that manufactured housing could be more easily design led through Information Technology (IT) and Computer Aided Design (CAD). Earlier periods of product manufacturing relied first on a 'sexy picture' to secure the research and development funding. Then various phases of physical prototyping would approximate the original design intent. As in site based construction, effort used to be required to retain the original clarity of design against the compromises and exigencies of pre-digital pre-production processes. Today the designers who work for product manufacturers can sophisticate an electronic model from initial presentation to replication in reality, spreading the cost of that R&D across the production run.

Meanwhile architects and the specialised construction industry design consultants on whom they rely, have a single fee for a one off 'architectural concept'. This is interpreted and diffused by everyone else on 'the team', on down to the lowest tender sub-contractor having to solve the practical problem with whatever standard of drawn information is issued in time. IT and CAD in manufacturing off site, Miles insisted, was the only way designers will reassert themselves over problems of production. Control is not really about the type of contract - it was an issue of economies of scale in digitally enhanced manufacturing industry.

Economies of scale in capitalised factory production did not mean sacrificing customer choice for quality at low cost either. Miles pointed to Japan, where '… you select your house from a portfolio of designs'. Consequently, '… the number of options you are given is almost infinite, based on the flexibility that comes from building in a factory.' (3) This is true, but should not be overstated. Most people in the developed world do happily accept that contemporary consumer products are increasingly produced as combinations from the improving range of forms, functioning services, and finishes from which we make our selections. We do this either at the time of ordering, or by choosing from the abundant stocks on offer. The choice is not infinite but as wide as commercially viable, and because failures are rejected unsold, extensive market research works to restrict product ranges to popular choices.

Miles makes the point that volume site built housing is not too dissimilar, except that the choice of form, function and finish is too narrow and low quality, and the stock is not sufficiently abundant. However the selections of components are assembled in the open air, often in no particularly sensible order, and to hopeless degrees of inaccuracy and wastage. As Miles appreciated, a limited choice of designs can't be built on site to a consistently high quality, and certainly not to any degree of complex curvature of form.

In mature manufactured product, the closer and closer you get to it, the better and better it looks. I look at a building site and the closer and closer I get the worse it looks.

'In mature manufactured product, the closer and closer you get to it, the better and better it looks. If you look at a well engineered car today, go closer and you will see that the detail is better. Because it is made to be manufactured efficiently, it is made to be durable, every single element on the whole vehicle is individually engineered to a very high standard, the curvature is continuous across the join, and we expect it to work.

It took me a long time to realise why the building industry is the way it is. I look at a building site and the closer and closer I get the worse it looks. But actually it is optimised, and that's the way it will stay forever unless something makes us change.' (4)

His insight, through the investigations of The Housing Forum, is that quality depends on investing in the way choice can be repeatedly delivered. From the point of view of the capital investor, the promotion of the myth of bespoke design and hand crafting is an evasion of the fact that a narrow site based optimisation cannot deliver quality. The idea of bespoke site built architecture flatters the designer, but the lack of capital investment in economies of scale in production are the source of the designer's recurring frustrations about construction managers and site labour. Homing in on Excellence is worth quoting at length on this point:

'The industry is very fragmented. There are only 36 companies building 500 or more dwellings per year and, whilst the largest of these delivers around 11,000 units pa, only six companies build more than 5000 units pa. The aggregate of annual construction by the companies is 95,000 units. The balance (55,000) is delivered through a great number of small housebuilders. The largest single producer category in the country is actually self-build, with around 15,000 units pa being delivered at the latest count.

Even the large companies may be quickly disaggregated. Very little direct labour is employed: most companies operate as management contractors, passing the majority of site based work to a wide variety of sub-contractors and self-employed individuals. With the exception of land-banks (most significant builders hold more than a year's stock of plots), investment in fixed assets is very low. As to supply, only the largest builders have begun to address supply chain management as a key discipline. Most of the rest operate loose supply chains with little in the way of formalised management and committed volumes.

If all this sounds antiquated and outmoded, don't be fooled. It follows from decades of free-market response to a demand that fluctuates quite widely from location to location and year to year, and is focused obsessively on first cost (rather than running costs, quality, reliability or any of those other classic manufacturing mantras). The result is a highly elastic, extremely low-cost delivery system that makes no demands on risk capital. Indeed, some of the better-organised medium-sized builders come close to being the ideal "virtual company", employing few workers of their own but operating at numerous locations which change quickly in response to economic forces. Whilst doing this, many of them have returned profits consistently in double digits over the last 10 years. This type of commercial performance takes some beating!' (5)

If all this sounds antiquated and outmoded, don't be fooled. Some of the better-organised medium-sized builders come close to being the ideal "virtual company", employing few workers of their own but operating at numerous locations which change quickly in response to economic forces.

Miles has explained that it will take brave investors to break this optimally under-capitalised site based practice, because sufficient return is available for minimal risk and sustained by restrictions on land supply delivered by the planning system. He appreciates that the construction industry often benefits from investment at the level of individual building components, and many manufactured products that go into buildings are advancing.

Yet Miles knows that construction must be capitalised at the level of whole house units if the industry is ever to integrate already specialist designers into a more sophisticated division of labour. This would provide an employment in which design time is afforded by economies of scale in repeat production, and the product improved as the design team's knowledge is consolidated through cycles of manufacturing and after sales experience. Ian Abley 31 July 2002

This report continues over three more pages

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