In 1972 the Principle Assistant of the R & D group gave an address in York in which he spoke about OXSYS - the computer aided design system for Oxford Method. As already mentioned in this manual, many services had to be accommodated in a limited space this put in clear terms the problem faced.
The primary aims of method building are directed towards improvements in construction and use. Oxford Method uses its limited range of factory-made components and dry construction to achieve rapid building. It uses detailed performance specifications for its components to achieve a high and reliable standard of building performance. It uses its planning discipline, and the predefined relationship between structure and services to achieve the flexibility necessary to accommodate future changes in use. All this relates to the building during its existence on the ground. However, method building has important secondary aims, which are directed towards the simplication of design. Method building uses design firstly by limiting the range of possible situations, then by providing standard solutions for those situations that are allowed. As an example, take the partition in Oxford Method. There exists a standard set of dimensionally co-ordinated partition units. They naturally have an intrinsic discipline based on their modularity. Taken by itself would not be a severe discipline; in fact the range of units is such that it is probable that any layout could be constructed provided that it adhered to the modular grid. However, Oxford Method imposes a much stricter discipline on partition layout than the intrinsic geometry of the partition units demands. Extra rules are provided which have the effect of avoiding consequential clashes between structure and services. So although the designer has to sacrifice a certain amount of flexibility in locating partitions he subsequently recovers adequate room for manoeuvre when locating services.
It is this side of method building that makes it peculiarly suitable for computerisation. Taking everything into account at every stage of design is a daunting task for man or machine. Even architects fail at it; they then revert to a cyclical mode of operation and will go back and alter an earlier decision in order to get out of the difficulty. This would be very difficult for a computer. Though it is not hard to detect that something has gone wrong it is very very difficult to get a machine to decide which earlier decision to alter.
However, that part of the discipline of method building which relates to design greatly simplifies the task. Because the rules for performing an early tasks, such as locating partitions, guarantee sufficient freedom to perform subsequent tasks, such as locating services, the design process becomes linearised. In addition the design of any one element is less dependent on a knowledge of the design of all the other elements (some of which have not yet been designed anyway); instead it becomes dependent on a set of formalised rules. These are the things that make computer-aided design realisable.
OXSYS - the computer aided design system for Oxford Method - it is intended to cover design operations from the point where these advantages come into operation. This means broadly speaking that it commences at the end of the sketch design phase, and carries through detail design, structural and service design, to production documentation. A number of computer applications have already been found in these areas - for example environmental evaluation, structural analysis, pipe sizing and the production of bills of quantities. Conventionally these tasks would be performed independently. Drawings would be measured and codified, data prepared and the individual program applied. The results would probably emerge in tabulated form - eventually the result or its implications would be recorded back on the drawings. The drawings are the ultimate authority - the progress of design is represented by a gradually developing set of drawings.
The fundamental concept of OXSYS is to replace these drawings by an alternative image of the building. This image is stored, not on paper, but in the memory of a computer.
E M Jones 1972
By 1981 the computer use in design has become a major factor. In 1981 the Regional Architect outlined its use then known as CAD (Computer Aided Design) and its specific use in designing drainage.
The Real Achievements
The main achievements arising from the application of CAD by the Oxford Regional Health Authority can be considered within two main categories. The first category is concerned with the development of techniques and systems. This is probably the most important area since the benefit of the effort involved has the potential to be multiplied by the number of projects on which the techniques and systems are used.
The second category concerns the resulting buildings since they are the ultimate test of the success or otherwise of the techniques and systems which have been developed.
In a number of cases calling upon the computer to assist in the handling of a complex design problem has resulted in the problem itself being better understood, the solution to it being greatly simplified and paradoxically the original need for the computer in some cases being virtually eliminated.
Such an example in Oxford Method has been drainage. In hospitals drainage is complex, almost every room in a hospital having at least one sanitary fitting of some kind needing to be connected to drainage. Conventionally, drainage design has required great skill and experience on the part of the designer with an ability to create three-dimensional contortions, capable of maintaining smooth, unblockable gravity flows through and around building structure and other services. In practice, drainage design in hospitals has been of a poor standard with a maintenance cost second only to painting and decorating; a natural candidate for CAD.
It was when trying to develop an algorithm to check for clashes between a circular pipe in a herringbone drainage layout, suspended to variable falls, and the variable sized steel angle diagonal members of a lattice truss, that it was realised that one was trying to solve the wrong problem.
A very systematic and intensive examination of the drainage problem was embarked upon. The result was a drainage system have an orthogonal lay-out; three pipe materials, PVC for general drainage, glass for laboratories and spun iron for very hot waste (eg kitchens); two sizes - 50mm and 100mm and a standard fall of 1:60. With a 300mm grid the pipe falls 50mm every ten grids, so the problem of calculating invert levels is simply one of counting grids. The previously intractable drainage problem, requiring the most experienced skills was reduced to a simple game, capable of being played by the least experience designer but producing superior solutions.
The same rules apply also to below-ground drainage with the added advantage that, suddenly, parallel runs of foul and surface water drains having identical falls can occupy the same trench and indeed the same mahholes, foul drains having sealed access rodding points. On a recent building a cost comparison between conventional drainage and the new system indicated a 20% cost saving.
E. H. Jones, Regional Architect, 1981
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