Oxford Method Research Programme

In September 1964 the first publication was issued on Oxford Method called Handbook of Building Assembly. Detailed thought was given at an early stage to the importance of flexibility that allowed buildings to accommodate sanitary fixings in any position and if required could be rearranged at a later date.

Two forms of floors were considered:

1. As a basement or semi-basement incorporating plant and services below a suspended ground floor.
2. As a normal oversite slab which forms the structure of the ground floor itself.

In the case of buildings with a basement or semi-basement (later called an undercroft) drainage runs were located on the supporting steelwork normally using metal, plastic or pitch fibre pipes. Connections to external drainage was kept to a minimum, ideally one central collecting point.

Where the oversite slab was also the ground floor all the drain outlets were predetermined in relation to internal partition units. Hole positions in the slab were therefore critical and drains were requested to be set out to an accuracy of +/- 1/8".

External drainage was also installed at the same time as that in the undercroft, in trenches excavated at the time of levelling the site.

It was not only soil drainage that went into the undercroft, water, gas, electricity and rainwater had to be accommodated.

In a publication in Modular Quarterly no. 3 dated 1965 the need to address this problem was highlighted.

Modular Co-ordination Services

The success of any dry-assembled building is dependent on the way the building components are integrated with services. The most efficient assembly will fail if the fixing and runs of service are not predetermined within the structure. The speed of assembly of service elements on site must go hand in hand with the assembly of building components. Ideally the service pipes should be incorporated within the building component in the factory, but if this is not possible the designed of components must make sure that the expensive unit is not ruined by the outcome of a controversial discussion between the general contractor's plumber and the subcontracting engineer. The decision about the exact location of an outlet or a run of a service pipe must be predetermined in relation to the required location of the component on plan, then in relation to the outlet through the floor of ceiling and finally through the partitions. Each service run must be allotted its position and its terminal point, and it is here where the use of modular grid comes into prominence when plotting the services within the structure. The hospital services network incorporates hot and cold water services, waste and drainage pipes, medical gases, suction, pneumatic tubes, telephone and radio points, nurse call system, staff location system, emergency lighting, automatic food deliveries, lifts, etc. etc.

Ground Floor Service Zone

At ground level the principle of the horizontal services void is continued by providing a basement 12M deep. Constructionally it is intended to scrape and level the site and then cast foundations for the frame together with laying a slab which is used as a working surface. From this working platform the main structural frame is erected. The floor above the working slab consists of precast concrete units carried on a series of small steel channels, which in turn are supported by a number of small stub columns. Again the design is aimed at flexibility and allowing free passage of services together with easy access.

Structural Floor Slabs

The main structural floor slabs are designed in 6M and 7M widths, and 16M lengths. Each slab is subdivided modularly into the dead zones and live zones from the services point of view. Dead zones for services occur, for example, either through the presence of a structural obstacle in the unit itself like reinforcement or structural rib of the slab, or may occur through the coincidence of the lacing apex or bottom which would obstruct the passage of a service pipe. All these dead zones are carefully related to similar zones in the partitions. The live zones form also structurally soft zones through which services can pass and meet with service connections of other components without interference with the structure of the component. Again for technical expediency the modular grid was used to co-ordinate the positions of the outlets. The points forming the soft spots of the floor slab are thinner than the rest of the slab and can be easily broken through for pipes up to 5" in diameter. The grid pattern of possible outlet points at most areas has a 3M flexibility in either grid direction with only a few points having only 6M flexibility. All soft spots are marked on the underside of each slab as well for identification to enable the engineer to extend the services at a later date without interfering with reinforcement when drilling.

The Modular Quarterly 1965 No. 3

Where the reference is made to M it refers to 4" in imperial or 100mm in metric.

The concrete oversite formed and the steelwork reinforcement in position to form the retaining undercroft walls	Steelwork to form undercroft in position	The Undercroft wall shown constructed and the stud beams ready to be moved and fixed to the wall.
A more general view showing precast floor slabs and the undercroft construction		Steelwork in position ready to receive floor slabs
Undercroft steelwork in position. Note the gap in the undercroft wall to allow the exit of the drainage and rainwater pipes		Slabs being put into position November 1967

Services in Ceiling Voids

Not only were services in the undercroft but also in the ceiling voids. The same disclipline applied. Drainage in a two or more storey building had to be to falls, this became the priority service. The lattice of the stud beams became a governing factor to calculate falls and distance. Rainwater had to be located in ceiling voids but not with soil drainage in the same space.

Large extract ducts could prevent the most direct route for soil and rainwater drainage. It became evident that the co-ordination of services was important.

Extract ducts in the ceiling void.