In this series of posts we take a look at a selection of historical documents outlining the development and construction of the British Iron & Steel Federation, Steel Framed House.
We currently hold thousands of archive items that have each been photographed and in some cases converted to text form for easier searching. This conversion method is an on-going process that will take several months to complete however we hope that you will find these never before published documents to be as fascinating as we have found them to be.
March 24th 1943
By H. T. TOWNSEND. ARCHITECT A.R.I.B.A.
In March, 1942 a plan was sent to Sir Leslie Scott and he sent the drawings and details to Sir Giles Gilbert Scott who in turn, forwarded them to Sir James West who is the Director of Post-War Reconstruction (M.O.W.P)
I followed up by writing to him and getting an interview and he at that time was not very impressed with the possibility of prefabrication. However, I got an agreement with him that I would submit a detailed drawings of the house so that he could give it full consideration, and the result was in June 1942 he wrote me a personal letter stating that a special Joint Committee of the Ministry of Health and the M. O.W. P. was being formed, and that he had seen that the drawings were put forward to this committee.
In August, Mr. Wordley, who through business had contact with Miss. Ledeboer, mentioned to me that she was dealing with this prefabrication as the secretary of the Sir George Burt Committee.
Mr. Wordley arranged an appointment with Miss. Ledeboer for me. When we arrived, she produced our drawings which had been submitted to Sir James West – that was in August 1942.
The first meeting of Burt Committee was held in December 1942 and then the committee appointed a Sub-committee to deal with my scheme. A meeting of this sub-committee took place about the end of December and they resolved that the scheme should be submitted to the Building Research Station at Watford for a report. The report was communicated to Miss. Ledeboer about the middle of January and I followed up by getting an interview with the people at Watford.
Mr. Wordley and I went to Watford and thoroughly discussed the whole scheme with their experts and an arrangement was made for me to submit a drawing showing the forms in which two of the experiments which they required, were to be carried out. Nothing further was heard for a month and Miss. Ledeboer was again contacted on February 14th, with a view to pressing the scheme forward. It was suggested to her that the experiments which the Research Station required would in any case be carried out by us before we commenced the construction of the house, and that in order to save time, we should be given a licence for the whole house and that the Research Station be invited to inspect our experiments at the time they were being carried out. Miss Ledeboer agreed that the criticisms raised by the Research Station were of not very great importance, and agreed to again submit our application for a licence for the experimental house.
No more has been heard officially from Miss.Ledeboe except that Mr. Wordley during the course of conversation with Miss. Ledeboer enquired as to the progress being made, and was informed that the Committee had NOT granted a licence for the house but are insisting on these preliminary experiments.
Document 2 – 13
A SURVEY OF METHODS AND PRINCIPLES AFFECTING DOMESTIC BUILDING IN THE POST WAR YEARS
By H. T. TOWNSEND. ARCHITECT A.R.I.B.A.
It may be anticipated that when the present war is terminated there will be an immediate demand for the construction of those a essential buildings such as houses end schools of which great numbers have been destroyed by enemy action and of which none can be erected during the period of hostilities. In order to produce these types of buildings In such large numbers as will be required. It Is obvious that other and speedier methods of construction will need to be devised to overcome the difficulties that will be en-countered. If the authorities adhere to the principle that all domestic buildings, schools end similar buildings must be erected by such out of date methods and materials as bricks, tiles and timber, upon which principle all the present building byelaws have been prepared.
It may be recalled that once before In the period subsequent to the 1914 – 1918 war, no real effort was made to anticipate the turn over from war to peace production. The consequence of such lack of foresight after the present war will be Intensified because this war has up to the moment called for greater sacrifices from the public than ever before and we may expect the public to demand from the government measures that will reward them for their efforts during the war.
The present methods of building construction will undoubtedly lead us into the troubles encountered after the last war and these need specific mention. The chief difficulty will obviously be shortage of materials particularly timber as much of this will be employed in rebuilding and repairing buildings damaged by enemy action. Labour will always be a source of trouble and loss of time owing to bad weather has at all times been one of the bugbears of the building trade. Similar troubles after the last war had the effect of increasing the cost of building to uneconomic limits and this must be one of the chief reasons for the adoption of new forms of construction taking no account of the fact that it has never been possible since then to provide sufficient working class houses at economic rentals by ordinary building methods.
If any proof were needed that these methods of building are out of date, surely the fact that all dwellings for the working classes need subsidising by both the Government and Local Authorities is a sufficient one. When one considers that in an ordinary six room house of the artisan type approximately 130 tons of material is used, it is time for more modern methods to be forced upon both the public and the builder, the latter of whom still persist in perpetuating ideas invented 6000 years ago by primitive peoples when clay was the only materiel then available for building.
Consideration of the evolution of the materials now used in the construction of houses and similar buildings will show that materials are still being used which not only limit the speed of erection but which have now became uneconomic in use. Bricks, tiles, slates and plaster are all examples of this class of material and although their use could be justified in times when wages were much lower and the output of the building operative very much greater than to-day, they should no longer be used if economy in construction is to be considered as an essential part of post war development.
They were all invented hundreds of years ego when the choice of suitable material for building purpose was very limited and of necessity this choice was restricted to a material which after being excavated from the earth required only a few primitive processes to render it suitable for elementary forms of building.
As used to-day they are a development of the primitive form used in ancient times and within limits their size has been determined by manufacturing requirements such as change of shape and shrinkage in burning and for ease of handling when laying.
Bricks are normally used in a 9″ wall in house building and it is generally recognised that such a wall is never weather resisting unless in exceptional circumstances. This thickness is required by the byelaws of Local Authorities in order to obtain stability only, the question of weather resistance is not specified by the byelaws beyond requiring the brick to be sound, hard and well burnt.
Mitchell on building construction states that a good brick must not absorb more than 15% of its own weight of water and that generally bricks absorb from one fifth to one fifteenth their own weight in water. Obviously an absorbent brick will give up its water content more quickly than a more dense brick but in all cases it may be said that in hot weather a brick wall will absorb a greet deal of water which may be. driven through its thickness when there is a wind with the rain.
It Is also a well known fact that when a more impervious brick is used there is generally trouble with adhesion in the mortar joint, with a consequent reduction in weather resistance of the wall and it is usual to reduce the strength of the mortar to attain the requisite adhesion.
It is known that bricks were used in building some six thousand years ago, but that is not a good reason for continuing to use thorn in post war building. It has been said that the labour required in processing and manufacturing bricks represents practically the whole of their cost, but that is not true when one remembers that the cost of haulage alone quite frequently amounts to a quarter of the coat of the bricks at the yard.
Therefore, if a Local Authority endeavours to obtain weather resistance In a 9″ wall, it must needs specify both the brick and the mortar in exact terms and in addition would require a very large staff of inspectors to see that the proper materials were being used and to insure the high standard of workmanship necessary to obtain a weather resistant 9″ wall.
As it has been recognised that solid 9″ walls are not sufficiently weather resisting other forms of construction are used, notably cavity walls, but these are not met with in ordinary speculative building. This is a fairly efficient wall when carefully built but has many inherent troubles which can only be surmounted by the use of vertical and horizontal load damp courses, which add even more to the cost of building in brickwork.
Tiles were probably first used in England about the 14th century and were obviously a substitute for thin roofing slabs of stone or slate. They were developed in those parts of the country where such material could not be quarried locally. It called for much ingenuity to devise a method of lapping and bonding these materials to obtain a waterproof structure and necessitated the use of special tiles for hips, valleys, ridges, gables and eaves, lead or metal flashings, soakers and aprons and similar primitive methods are still employed to-day except that far too often a cement fillet takes the place of this metal.
A consequence of these forms of roofing were the high pitched roofs constructed of timber which, in those days was the only suitable material available in quantity in England, and a further complication was brought in by the need for gutters to prevent the walls being saturated by the water from the roofs.
Many flat roofs were constructed in these times but as lead was used to cover them they were so expensive that they could only be used on Churches and similar buildings where more money was available. Thou we find that the use of thatch, tiles or slates was general for domestic building for economic reasons and such forms of roofing have now become traditional.
This tradition still requires a house to be roofed in a form devised in medieval times to overcome the limitations imposed by lack of knowledge end economy in construction. Although many forms of roofing, in materials which are more durable, are now available, tradition requires that they shall be formed of small squares of burnt clay supported by timber which now has to be imported from foreign countries. Such roofs in stormy winds being far from durable, requiring constant attention during their life and as has been seen on numerous occasions during this war are stripped by the hundred from the blast of a single bomb.
One of the advantages of such a form of roof in that it provides adequate space for water storage tanks which in winter became frozen and thus provide the unlucky householder with plenty of exercise.
The use of plaster in present day building is also a tradition. It was used on walls in medieval days for the sole purpose of covering the lumps and inequalities of stone or brick walls. It was particularly well suited for its use in the ornate and Intricate patterns moulded on the ceilings of medieval houses and such practices were continued until the beginning of the 1914 – 1918 war.
It is not a hard wearing material and gives constant trouble in the small house of to-day both in walls and ceilings, and in order to preserve it as much as possible the householder requires it to be covered with paper. It has no value whatever as an Insulator against heat or cold and no other single trade presents as much trouble as plastering In the erection of houses. It is affected in erection by both frost and humidity and if satisfactory results are to be obtained requires great care in the selection both of its component material and the labour to apply it.
One of the most damaging arguments against the use of buildings erected to prefabricated forms will be the old and worn tradition which demands the use of local material. This may well apply to development near beautiful villages as for example in Derbyshire or the Cotswolds and for aesthetic reasons one could not offend such principles. But In urban development or development around the location of Isolated Industries this criticism cannot apply.
Many or most of the suburbs of large towns now present such a conglomeration of material, both foreign and home made, that whatever form is adopted it cannot harmonise with its surroundings. Further it must be recognised that local material may not always be of good quality and cannot always be produced In sufficient quantity. In addition, the local tradition however beautiful is most probably no longer economic and in such circumstances surely It Is better to depart from tradition entirely than to aim at some cheap and tawdry imitation of the real thing.
Again the beauty of such villages very often depends upon the diversity in design of the various buildings which make it, but then large numbers of houses are erected nearby and great trouble is taken to produce the character of the old buildings, the beauty of the original village is more often than net lost.
It is a reasonable conclusion therefore that if we are to erect these essential buildings rapidly and cheaply with the most economic use of labour, material and transport and some form of construction will be adopted which will enable structures to be made in factories in tremendous quantities and transported to the building sites for erection.
This method has already been envisaged In England and practised in other countries and prefabrication has up to the present been the term applied to describe such processes.
Prefabrication should mean the production in a factory of an entire building complete with plumbing, electrical installations and heating appliances and designed to admit of the speediest erection at the site. This is a method by which the greatest economy of labour and material can be achieved, as it will be obvious that man-hours output In a factory Is greater than at the building site where great wastage of labour occurs. Similarly a great reduction can be made in the wastage of material when the various kinds used in construction are reduced to a minimum as in this method as opposed to more usual present day methods.
One of the most popular destructive criticisms levelled against this form of construction is that it does not lend Itself to individuality In design and that one of the results of its use will be the erection of thousands of “mass produced” boxes. This criticism equally applies to practically all pre war housing end estate development carried out by speculative builders who have used a plan which is a standard practically throughout England and who have used standard windows, doors and units in all their development in order to achieve economy in building. The results attained by these methods have been more or less successful from a financial point of view but no one can say that the appearance of the houses reaches a high standard of design. Where “individuality” has been expressed in the design it is seen in such features as gables, bay windows of abnormal shapes, sham half timber, leaded lights, porches end similar ornaments which have been embodied with the sole object of making the house “attractive” and saleable to a poorly educated general public.
When using a prefabricated form which we may assume will be designed by a competent person, such Individuality will not be possible, but there is no reason why in using a standard unit of walling or roofing material that an individual design cannot be produced. Further if any control of development is intended after this war, and we can assume that a competent person will be employed to co-ordinate the design and layout of estates, a real designer will be able to avoid any appearance of monotony by the planning of the estate. It will be just as easy to produce three or four standard types of houses with prefabrication as with the ordinary pre war building methods and provided that standard parts and dimensions are used any Individual plan can be prefabricated.
According to published figures the total number of houses erected between the years 1919 – 1941 was 4,233,692, and in the years Immediately following the last war production was well below the average, for the reason that shortage of material and labour with the exceptionally high cost of building prevented production reaching normal levels. On these figures it would appear that the average annual production of houses was approximately 800,000 of which about two- thirds of the total were built by private enterprise. The total cost of the houses produced during these years was in excess of £800 million and the average amount for a year approximately £40 million.
The position after the present war will be very serious if the production of houses cannot be increased far beyond that implied by the figures given above. It was estimated by the Engineers Study Group in 1941 that if the present hostilities lasted for five years no less than two million houses would be required for replacements alone not taking Into account ordinary peacetime requirements for replacements, which may be 60,000 houses per annum. It would now appear that the estimated number of houses required in England Immediately after the war will be between four and five million. At the pre war rate of house building it will take 16 to 20 years to produce these requirements and this period of time may prove far too long for the patience of the general public, who are now seeing what amazing production efforts can be made for the purpose of war. It will be obvious to them that such production can be achieved for peaceful purposes and they may demand that the effort be made.
If the production of three million houses is to be achieved within a reasonable period after hostilities cease, such a reasonable period being assumed as five years, that will need a production rate of approximately a half a million houses per annum at the least, which is over twice the number provided by ordinary methods in pre war development. Assuming the cost of houses after the war to be in the region of £500 each, this means a total expenditure for housing purpose £1500,000,000 spread over five years.
These figures may of course be challenged, but It is fair to assume that they are reasonably correct, if the requirements of housing after the last war are any guide.
If we assume that during the period before the war that the whole of the building industry was usefully employed then it may be concluded that with the numbers engaged the maximum output obtained cannot be increased if the same constructional methods are still to be used. Therefore some other procedure must be adopted, not only to allow for greater output, but also to absorb larger numbers of people In the building Industry.
An obvious solution to the problem will be to devise methods of construction which will enable buildings to be wholly fabricated and manufactured as far as possible by machinery in factories. This will enable many of the workpeople who have been trained to handle machinery to be employed in the building Industry it will find a use for many of the factories which have been built for war purposes and possibly much of the plant which has been installed to deal with war production. Another Important aspect is that this method of constructing buildings will help to avoid the wholesale discharge of workers which will occur when war production is slowed down or stopped at the cessation of hostilities, and in addition if proper materials are selected in the construction it will help to absorb much of the output of steel which has been stepped up to uneconomic peacetime limits solely far the purpose of making munitions of war.
For these reasons alone it Is suggested that for some years after the war “prefabricated” building will solve many problems besides that of quick house production and will give time for the building Industry to cope with disorganization caused by the war years, to train more building operatives and to concentrate on the rebuilding of damaged buildings in the larger cities.
In giving consideration to the problems imposed In the design If a prefabricated house, the following requirements were regarded is essentials:-
1. To reduce to a minimum “wet” methods of construction.
2. The units should be light and capable of being handled by one man without being so fragile as to be easily damaged.
3. They should be as large as possible but still able to be handled by one man.
4. They should provide thermal Insulation at least equal to ordinary building standards.
5. They should be hygienic with regard t6 vermin, dust and dirt.
6. They should be weatherproof when used externally.
7. They should not be unsightly.
8. The panel should be fire resistant.
9. They should be so designed that they can be made wholly by machinery.
10. The materials of which the panels are made should be In good supply, cheap and easily obtainable, and as few In number as possible.
11. The units should If possible be designed to admit of their use as both wall and floor panels.
12. It was not considered necessary that the wall panels should be load bearing panels.
13. Prefabrication of the plumbing, lighting and heating service was an essential part of the design, but could not be attained unless It was considered In the planning of the building.
The probable shortage of timber In post war building to be taken In account and the system be designed to obviate the use of timber entirely. The panel used in the Townsend house meets all the requirements previously mentioned. It can be made In various sizes from 9 ft high by 4 ft wide down to 6 ft by 2 ft or less. The total weight , of an 8 ft x 4 ft sheet is about 120lbs and it provides insulation against heat and cold about three times as great as that provided by a 9″ brick wall plastered on the inside. It consists of a sheet steel plate corrugated to a depth of 8″ with flattened crests alternating on each side of its thickness and this former supports on each side fibre wall boards 1/2″ thick, which are scoured by clips which are integral with the former, the whole panel being fabricated at the factory and dispatched ready for assembly.
The following figures which are based on data from the handbook of the Institute of Heating and Ventilating Engineers show the resistivity of the wall slab.
Two 1/2′ thick fibre boards 2.94
2″ Air space .95
1/8″ Asbestos face .10
1/16″ Sheet metal .10
The Thermal Transmittance Coefficient expressed as B.T.U. lost per Square foot per hour for 1 deg. F difference In air temperatures inside and out for a resistivity of 3.89 = 1.85. The corresponding figure for a 9″ brick wall plastered on the inside is .36 – the resistivity of such a wall being 1.4.
Other relevant figures are:-
Roof slab C = .21 against normal roof losses of .87
Floor slab C = .26 against normal floor losses of .30
It will be noted that In the resistance figure 1/8 asbestos is mentioned and it should be pointed out that the outer fibre board is protected from the weather in the external panel by an asbestos skin fin this example. Alternatives to this finish can be provided and as in the asbestos sheet can be obtained in various colours.
The vertical joint between the panels is filled with mastic and covered by a non-ferrous metal strip which is fixed by pressing over a tongue formed on the edge of the metal sheet.
The horizontal joint is also sealed by a non-ferrous metal strip inserted between the two panels.
The internal partitions are of the same construction but no weatherproof facing is necessary and the joint is simply filled and painted. Owing to the large number of fixings obtained between the fibre board and the metal sheet no large movement can take place at the joint.
The floor and roof panels are identical to the wall panels except that the upper fibre board is omitted and the corrugations are filled to a depth of 4″ with lightweight concrete, screeded up and covered with linoleum, which forms the permanent finish of the floor. Other materials are available for floor finish if required but in the standard house linoleum will be used. The floor can be reinforced for special purposes where heavy loadings are anticipated.
A welded steel frame composed of cold rolled sections is used to carry off the loads of floors and roof and the external panels are welded direct to the frame by lugs pressed up in the metal formers, the lugs serving a double purpose by locating the position of the panel in respect to the frame and supporting Its weight whilst welding takes place. As the weight of the panel is only just in excess of a hundred weight it will be appreciated that these lugs need to be very small. The Internal partitions will be held In position at ceilings by metal grooved sections fixed to the ceilings and at the floor by metal lugs buried In the concrete.
Where doors and windows occur they will be accommodated In special panels of standard sizes which will be completely assembled at the factory and dispatched with the ordinary sheets. The heads and sills of windows will be finished with non-ferrous metal flashings and drips and the jambs and sill internally with pressed metal trims. Doors similarly will be completed at the factory and will be pressed metal construction with jambs and head finished with metal trims. Special closer pieces are also provided for making partitions up to specific lengths, staircase and balustrade will be of pressed steel with composition treads.
It will thus be seen that the numbers of different materials used have been kept to a minimum, they are of a type which can be Obtained under normal conditions quite readily and which in ordinary circumstances are economical.
As regards fire resistance the B.R.S. have stated that if the walls of staircase and hall are treated with fire resistant paint this process would make the internal fire risk satisfactory. There is no established basis for comparison for ascertaining the external fire risk, but It is certain that this construction is considerably better than timber tied buildings, of which great numbers have been erected in the past.
Plumbing and other services cannot be discussed generally but will be covered in the description of the specification of the experimental house. It can be said here that It is possible to cut down site work considerably by the careful planning of the house end that the systems can be almost wholly prefabricated.
Brief Description & Specification of Non-parlour house suitable for development by Local Authorities on the Townsend System.
As has been previously pointed out that by using this system of construction individual designs may be worked out for any type of building end there is no object in stressing any special features or merits of planning in the house to be described. It Is sufficient to say that the plan has been developed from recommendations made by the R.I.B.A. Committee. The amount of built in furniture to be provided Is also a point upon which various authorities are not all in agreement. It should be remembered that such fittings add to the initial cost of the building and are not always popular with the tenants. Some official schemes recently published have shown such a number of these fittings that the cost of the house will probably be increased by £150. or more. Therefore it should be understood that individual requirements in this respect will be met.
In one important aspect the plan differs from usual practice in housing schemes. It will be noted that a detached house is shown and in this construction such a building will be cheaper than if it were built semi-detached or in blocks. The author feels very strongly upon this point and has purposely put forward this proposal. Many eminent people and authorities have recently suggested that future housing development should be largely in the form of blocks or terraces of houses, but it is generally accepted that detached houses are very much desired by the people who have to live in crowded communities. There is no reason why any more land is necessary per house plot although possibly more frontage is required. This is not to say however that blocks or terraces of houses cannot be built in this system, but Is only pointing out that building costs will be reduced If detached houses are used. It will be necessary to build a pair of houses with a 4″ space between adjacent houses and this space will need to be filled with lightweight concrete to reduce the risk of firespread between adjacent dwellings.
The site of the house will be cleared of vegetable growth and prepared for a spread of concrete 3″ thick and graded about 14 – 1. Before this is laid the drain connection to soil and R.W. pipes will be laid and excavations made and concrete foundations for stanchions placed. The size of these foundations will be dependent upon the site conditions, but as the total weight of the house is only about 40 tons it will be understood that this will present no difficulties. Further, any sites which would present difficulties to ordinary building by reason of their excessive slopes in ground levels can be utilised with this system as the stanchions can be adjusted in length to suit site conditions. It Is obvious that in large schemes of development modern methods of site excavation and concreting by machinery will be adopted with a consequent saving in time and expense and moreover the absence of foundation trenches will make this an easy and speedy operation.
The next operation will be the erection of the steel frame which will be constructed of built up cold rolled sections welded together and owing to its light weight will not require any special erection plant. Positioning cleats and bolts will be supplied for quick erection and when assembled the whole frame will be welded together by the electric are process and finally the stanchion bases will be grouted up.
Floors and Roof.
The next step it the erection of floors and roof. These consist generally of 8′ x 4′ sheets with fibre board ceilings already attached and are simply slipped into position between beams and filled in with light weight concrete. This may be composed of an aggregate of clinker or foamed slag and fill be screeded up ready for floor finish. The lines of partitions will be marked out and battens laid in the concrete for withdrawal to accommodate the partitions when they ere fixed.
The roof will be similarly constructed to the floors, but the surface will be laid to falls to a single downpipe and will be covered with patent built up bitumen composition roofing material protected with 1″ cement and sand. The eaves projection may be made by a metal form which can be supplied with the houses and will be used for a large number of houses or alternatively a non-ferrous metal cornice can be provided with each house which will be filled with the roof panels; the overhanging cornice may require support until the concrete has set and this can be easily arranged by strutting from the floor below.
The external walls can now be erected and as has been previously stated these walls are 3″ thick with a corrugated sheet steel chassis supporting 1/2″ fibre board on each side the outer face being protected from the weather by asbestos sheet which can have a decoration and be coloured. The metal chassis will be rustproofed by a patent process and alternative finishes can be supplied for the outer sheet. The method of fixing intended is by spot welding to the metal frame integral lugs formed in the metal chassis and these also serve to support the weight of the panel and to position it in relation to the frame.
Special angle pieces are provided for external and internal angles of outer walls and composite door and window panels are fixed by the same method. When all panels are fixed on the ground floor horizontal weather strips are introduced between the joints of these and the upper panels which are welded into place and when the whole of the external wall panels are fixed the vertical joints are filled with mastic and covered with the patent weather strip which is fixed simply by pressing over a tongued strip formed on the edge of the steel chassis.
Internal partitions are now ready to be fixed and these are positioned by a metal channel which is bolted to the underside of the ceilings and also by the groove left in the concrete of the floors. The head of the panels are slipped into the ceiling channel, pushed into a vertical position and wedged up from below. The concrete groove is then filled and allowed to set. Special panels accommodating doors, angle pieces and closer pieces are provided.
Various finishes can be provided for the inside of the house, in general the Living Room end Bedrooms etc. will be finished with a plastic paint. Bathroom, kitchen and Utility Room can be finished with a rexine veneer and in special positions round sinks porcelain enamel splash backs will be fixed.
In prefabrication the introduction of special finishes on either side of a panel in order to aim at delivering a completely finished article on the site adds considerably to the number of different component parts and it is therefore intended that all special finishes shall be attached at the site. Recently great advances have been made in the technique of spraying permanent finishes on various surfaces and it is anticipated that such methods will be taken advantage of by local authorities in the decoration of houses for the working classes. It is also contended that any panel incorporating a finished coat or veneer will suffer damage during the course of transit and fixing and therefore for this reason it has been decided that no system embodying this provision can be entirely successful and that the method suggested above is a much more satisfactory solution.
The staircase and balustrade will be of pressed steel and treads will be finished with a composition pad.
Windows and Doors.
These will be of standard sizes, windows of the casement type and doors of pressed steel with cores of insulating and sound deadening material. The trims and finishes to openings have already been described.
Heating and Hot Water.
Alternative methods of heating can be embodied as desired and in the house illustrated advantage has been taken of the extremely low heat losses in this type of construction. A back to back fire is shown which provides an open fire in the Living Room and a cooking oven in the Kitchen. A gas cooker is also shown. The open fire can be used with a back boiler to provide hot water for domestic use and also for heating the Hall, Landing and three Bedrooms by means of radiators. This single fire is capable of this work only because of the thermal efficiency of wall, floor and roof, the losses in which are considerably lower than in a brick built house. This is an important feature of the construction which has the effect of making central heating possible in a house for the working classes not only from tha point of view of initial expenditure but also of running costs. The calculated heat losses for the rooms mentioned allowing for ample ventilation are as follows:-
Hall 2 Air Changes 2655 B.T.U’s per hour
Landing ” ” ” 1626 ” ” “
Bedroom 1 ” ” ” 3097 ” ” “
Bedroom 2 ” ” ” 2757 ” ” “
Bedroom 3 ” ” ” 1795 ” ” “
This figure shows that one lb. of good coal per hour (14,500 B.T.U’s) will be more than sufficient to heat the house with freezing temperatures outside.
The plan has been designed to obtain the best results on the domestic hot water circulation and it will be noted that if the H.W. calorifier is placed immediately above the pram space and directly below the tank cupboard, the shortest possible run of circulating pipes is necessary. It should also be noted that the hot water service pipe feeds the bath and lavatory basin on its way to the sinks in Kitchen and Utility Room and also may feed a towel rail in the Bathroom. It is anticipated that if the calorifier, supply and circulating pipes are adequately insulated against heat losses that hot water can be supplied for the maximum domestic use for a further one lb. of coal per hour so that for wintry conditions 3cwts. of coal per week will provide heating, hot water and cooking facilities for the whole house and that a average for the winter months would be about 2cwts. of coal per week.
Similarly if electricity is used for heating a corresponding saving in cost will be effected and it is suggested that where Local Authorities own their own electricity supply company it will be possible to heat this house entirely by electricity at a cost well within the compass of the ordinary working man’s pocket.
Further experiments in heating these houses by electric thermal storage tanks taking electricity on a time rental switching system are to be carried out and it is confidently hoped that this system will prove successful chiefly on account of the fact that the scientific design of the structural panels cuts down the heating load to the point where such methods become economic possibilities.
The method of providing hot water has already been mentioned and the position of the various components indicated. It should be noted that these positions lend themselves to quick assembly on the site, the tank and calorifier being incorporated in a pre-assembled cupboard which will be delivered complete to the site. The whole of the pipes inside this compartment already being in position, the plumbing panel behind the bath (which also contains waste pipes and service pipes in position) is placed in position and connected up, the bath wastes and lavatory basin only needing connection to the plumbing panel. The sinks are similarly fitted up complete with taps, services and wastes, it is therefore only necessary to connect up the service pipes between the fittings. It is intended in post war development to use copper service pipes internally with a “Kontite” or similar joint.
The “one pipe” system has received consideration and can if necessary be incorporated in the system, but for various reasons it has been decided not to use this method. The plan shows a separate soil and ventilating pipe and a combined rainwater and waste pipe. Where this system offends local bye-laws a separate rainwater pipe may be used. All the pipes are flange Jointed cast iron and are brought down inside the walls of the house.
Vitreous china W.C. pans are used, flushing valves being used instead of cisterns. Lavatory basins can be of porcelain enamelled steel and the sinks are of similar metal with one piece skirtings and draining board. Alternatively stainless steel sinks and drainer may be incorporated at extra cost.
These are confined to the minimum and can be omitted if necessary. It is, however, thought that the Kitchen sink fittings is essential and that the built-in wardrobes between the two large bedrooms is very desirable. The airing or drying cupboard in the Utility Room has been suggested as an essential by the R.I.B.A. Committee and is ventilated through the outer wall. No special ducts are considered necessary for ventilating purposes as the hollow walls lend themselves admirably to this purpose. Pipework has been accommodated for the most part in the cupboards and plumbing panels mentioned which will give easy access in case of breakdowns.
A refrigerator is shown in the Kitchen but this can be omitted if regarded as too costly, it is in any case not an essential part of a prefabricated building.
As far as possible switch drops and switches will be incorporated in the door assembly, switches being located on the architrave of the opening. If the 3-plate wiring system be used the minimum amount of wiring on the site will be necessary. The possibility of pre-assembled wiring systems are being considered and it is hoped to be able to embody this development in the experimental house.