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British post-war temporary prefab houses were the major part of the delivery plan envisaged by war-time Prime Minister Winston Churchill in March 1944, and legally outlined in the Housing (Temporary Accommodation) Act 1944, to address the United Kingdom's post–World War II housing shortage.

Taking the details of the public housing plan from the output of the Burt Committee formed in 1942, the Conservative Party's Churchill proposed to address the need for an anticipated 200,000 shortfall in post-war housing stock, by building 500,0000 prefabricated houses, with a planned life of up to 10 years within five years of the end of World War II. The eventual bill of state law, agreed under the post-war Labour Party government of Prime Minister Clement Attlee, agreed to deliver 300,000 units within 10 years, within a budget of £150m.

Through use of the wartime production facilities and creation of common standards developed by the Ministry of Works, the programme got off to a good start, but foundered through a combination of commercial rivalry, public concern, and pure cost. More expensive to build than conventional houses, the envisaged excess production capacity of materials was taken up at a quicker rate through Britain's post-war export drive to reduce her burgeoning war-debts.

In the end, of 1.2 million new houses built from 1945 to 1951 when the programme officially ended, only 156,623 prefab houses were constructed. Today, a number survive, a testament to the durability of a series of housing designs and construction methods only envisaged to last 10 years.

Context
The combined impact of war and a lack of commercial high street activity, creates many post-war shortages and resultant economic inflation, not the least of which is in housing stock. In post–World War II Britain, this was increased through the use by both sides of carpet bombing from great altitudes, which had a huge effect on both the number and quality of available housing stock. Estimates at the time suggest that the minimum shortage was some 200,000 houses nationally. The result was the duplication of a strategy deployed by the post–World War I government of a country-wide investment programme in a national public house building scheme.

In envisaging the problem, Prime Minister Winston Churchill had set up the cross-party Burt Committee in 1942. They sent British engineers to the United States from late 1943, looking at how America - a world leader in prefab construction, thanks to its war focus - intended to address its needs for post-war housing.

The outcome of the Burt Committee was that it favoured prefabricated housing as a solution to the problems. In a radio broadcast in March 1944, as the War in Europe was concluding, Churchill announced a Temporary Housing Programme, known officially as the Emergency Factory Made or EFM housing programme. The vision was for a Ministry of Works (MoW) emergency project to build 500,000 ‘new technology’ prefabricated temporary houses directly at the end of the war: The emergency programme is to be treated as a military evolution handled by the government with private industry harnessed in its service. As much thought will go into the prefabricated housing programme as went to the invasion of Africa. This vision and promise passed into law as the Housing (Temporary Accommodation) Act 1944, which planned to build 300,000 prefab houses in Britain over the next four years, with a structural lifetime of between 10 and 15 years. In fact just over 150,000 were built.

However, rather than relying on private sector investment as in the United States, the new Labour Party government of Clement Attlee, having been part of a war government that deployed large and efficient production schemes to win the war, simply applied the same theory to this problem. The plan was also in part an economic solution, as it reduced the need for a post-war government laden with debt having to subsidise commercial operations, a problem avoided by simply encouraging them to work together to design and produce the paid-for solutions. The solution providers were hence already equipped for mass manufacture, and made capable of post-war transition through fulling a great economic need.

But the scale of the problem was highly under estimated. At the end of the war, it was found by survey that more than three million houses had been damaged by enemy bombing, almost a quarter of all homes in the country. Most of the damaged stock was in London and the southeast, particularly in areas hit hard by Hitler's vengeance weapons. Although the building trade had taken a beating, with many of its skilled labourers killed whilst on duty as foot soldiers, the recovery in labour levels was boosted by high post-war unemployment. The envisaged shortages of basic building supplies did initially exist, but were quickly turned around: basic supplies of sand, gravel and clay to produce bricks and cement were natural resources within the geography of Great Britain, they just needed extracting.

By 1951, the EFM housing programme and its off-shots had added one million council houses, resulting in 15% of all the dwellings in Britain became publicly owned, more than the proportion in the communist Soviet Union at that time.

Standards
The MoW created research institutes, standards and competition authorities that resulted in core building regulations. Although essential at the time to ensure quality, the way in which they were implemented from a regulatory view point defined and restricted the whole of the British construction industry, until the reforming non-centralist government of Margaret Thatcher some 35 years later.

All approved prefab units had to have a minimum floor space size of 635 sqft, and be a maximum of 7.5 ft wide to allow for transportation by road.

The most innovative creation of the MoW was what was termed the "service unit," something which the MoW initially specified all designs had to include. A service unit was a combined back-to-back prefabricated kitchen that backed onto a bathroom, pre-built in a factory to an agreed size. It meant that the unsightly water pipes, waste pipes and electrical distribution were all in the same place, and hence easy to install.

The service unit also contained a number of innovations for occupants. The house retained a coal-fire, but it contained a back boiler to create both central heating as well as a constant supply of hot water. For a country used to the pleasures of the outside lavatory and tin bath, the bathroom included a flushing toilet and man-sized bath with hot running water. In the kitchen were housed such modern luxuries as a built-in oven, refrigerator and baxi water heater: items we now take for granted.

All prefabs under the housing act came pre-decorated in magnolia, with gloss-green on all additional wood, including the door trimmings and skirting boards.

Often very American is appearance and style, to speed construction many were developed on the side of municipal parks and green belts, giving their residents who had most often come from cramped shared rooms in inner cities, the feeling of living in the rural countryside.

House types
When the Ministry of Works opened up the design competition, some 1400 designs were submitted. Reviewed the Building Research Station, many were rejected from the conceptual stage, such as the British Powerboat Company's proposal for the Jicwood all laminated plywood design; while others were only dismissed after the prototype stage, such as the steel framed Riley.

However, only a few were approved after testing for construction:

Prototype - Portal
The first prototype to be unveiled was the motor industry contribution, a steel panelled experimental temporary bungalow called the Portal after the minister of works, Lord Portal. With a floor area of 616 sqft, and an estimated cost of £600 constructed, and £675 fully furnished. It included a prefabricated slot-in kitchen and bathroom capsule, that included a pre-installed refrigerator. The proposed rent was 10 shillings a week for a life of ten years.

Airey
Developed by Leeds based construction magnate Sir Edwin Airey, it was easily recognisable by its precast concrete columns and walls of precast ship-lap concrete panels. Due to its variation of design, available with a flat or pitched roof, and with variations for rural or urban sites; it became one of the most prolific of the permanent designs.

Arcon
Developed and hence constructed by Taylor Woodrow, the Arcon was an asbestos-clad variant of the Portal, with the same prefabricated kitchen and bathroom capsule. It had a longer life, but also came with a higher cost of construction. The later rolled top roofed Arcon Mk5 was developed by Edric Neel. 38,859 were constructed through the programme.

AIROH
The AIROH house (Aircraft Industries Research Organisation on Housing) was a 675 sqft, ten tonne all-aluminium bungalow assembled from four sections, each to be delivered to the site on a lorry, fully furnished right down to the curtains. The proposed rate of production of complete houses was to be an incredible one every twelve minutes. This was possible because the completely equipped and furnished AIROH could be assembled from only 2,000 components, while the aircraft it would replace on the production line required 20,000. The parents of future Labour Party leader Neil Kinnock were allocated at AIROH, on which he commented: It had a fitted fridge a kitchen table that folded into the wall and a bathroom. Family and friends came visiting to view the wonders. It seemed like living in a spaceship. Although impressive, the AIROH by 1947 was costing £1,610 each to produce, plus costs of the land and installation. However, as the design was so easy to produce, 54,500 AIROHs were constructed.

BISF


The British Iron and Steel Federation, an association of steel producers, was formed in 1934 in order to provide central planning for the industry. It was prominent in coordinating output through the War.

Post-war, BISF became key in the new housing programme. It sponsored a solution for a permanent steel framed housing to a design by architect Sir Frederick Gibberd, who also designed the Howard House.

The BISF is of a conventional design, with simple architectural devices of projecting window surrounds encasing Crittall Hope windows, and differing cladding to the upper and lower stories deal with the junction between components in an understated fashion. Traditional materials could be incorporated or simulated, for example a brick cladding to the lower storey, or steel sheet profiled to match timber weatherboarding to the upper. The BISF house also uses tried and tested methods, with a simple over-site slab ground floor and render on metal lath cladding.

Produced by the British Steel Homes company, the BISF was a successful design in numerical terms, thanks to the backing of its trade sponsors, who could ensure a supply of steel. The BISF also benefited from a guaranteed order of 30,000 units given directly by the Government in 1941.

Mortgages for BISF houses are available from a limited number of Lenders who now view such properties to have a similar lifespan to that of a traditional brick constructed house.

Cornish Unit
Designed by A E Beresford and R Tonkin for the Central Cornwall Concrete & Artificial Stone Co., they are also known as Cornish Type and Selleck Nicholls & Williams houses. The houses came in type1 and type2 designs, incorporating variations of a bungalow, two storey semi-detached and terraced layout with a medium pitched Mansard hipped roof.

The first floor is PRC clad over a single-storey concrete frame, while the type1 house has the Mansard roof over timber trusses. Internal walls are made of PC wall block or brick. So successful was the design, 30,000 Cornish Unit houses were eventually constructed.

However the roofs and wall insulation incorporated asbestos, while the wooden frame-based construction means that as the concrete decays the two parts tend to separate, resulting in large amounts of internal cracking. The major defects are:
 * Horizontal and vertical cracking of PRC columns
 * High rates of carbonation and significant levels of chloride in PRC columns
 * Cracking of first floor ring beams

Hawksley
A W Hawksley Ltd of Hucclecote, was formed in 1940 by the Hawker Siddeley group at the Gloster Aircraft Company factory to build the Albermarle aircraft designed by Armstrong Whitworth. Post-WW2, the companies parent Hawker Siddeley kept it open to supply prefab houses and bungalows to the MoW. After their MoW work finished, they continued for a period exporting their buildings to Australia, New Zealand and Uruguay into the 1960s. Their designs included:
 * BL8 - an aluminium-clad timber-framed bungalow.
 * C2/C3 - either a 3 bedroom bungalow, or convertible to a government building such as a Post Office or Doctors surgery
 * Hawksley House - a semi-detached or terraced house with 2-4 bedrooms based on the principles of the Swiss architect G Schindler
 * Hawkesley Single Storey building - a general purpose building suitable for schools, offices, hospitals and village halls

The company later developed an aluminium house for the Margaret MacMillan Memorial Fund, for use in tropical overseas relief missions.

Howard
Another designed by Sir Frederick Gibberd, the steel framed designed was privately promoted by John Howard & Company. A more industrial aesthetic design, and more adventurous in its use of innovative technologies. Asbestos cement cladding panels are clearly expressed with metal flashings over a base course of foamed slag concrete panels, with windows and doors fitting within the module set up by the cladding. Unlike the BISF this house proudly displays its lightweight prefab nature, but there are also technical advances that set the Howard House apart, for example the pre-cast concrete perimeter plinth that supports a suspended steel ground floor. Only 1,500 Howard Houses were built.

Laing Easi-Form
Designed by Laing and Co., as they are poured in-situ into moulds type designs developed from 1919 onwards, they do not suffer the problems of many steel framed buildings. The rare Mk1 version had 8 in thick solid no-fines clinker concrete walls, built in the period 1919 to 1928. The more common Mk2 version from 1925 to 1945 had cast in situ cavity walls, 3 in thick inner and outer Ieaves with 2 in cavity, usually finished externally with stone dashed render coat. Post 1945, The Mk3 version which make-up the majority of houses, was modified to specification, and hence had cast in situ concrete walls, inner and outer leaves of 3 in thickness separated by a 2 in cavity, and reinforcement in both skins located in four horizontal bands above and below window openings.

Mowlem
Like the Laing Easi-Form, a cast in situ concrete form of construction, first used in 1952 but mainly in the period 1962 to 1981. With a solid cavity wall, the poured concrete substitutes for the inner blockwork walls of traditional housing. Solid wall types 225 mm thick cast in lightweight concrete, rendered externally. Cavity wall types have an inner leaf of at least 100-125mm thick concrete.

Orlit
Designed by Czech architect Erwin Katona, who left Czechoslovakia in 1938 to relocate to the UK, the design is a two-storey precast reinforced concrete design. The design was produced in Scotland by the Orlit Co, resulting in most houses being located in Scotland.

On site construction was based on a foundation which supported pre-cast concrete columns at fixed intervals, supporting concrete beams fixed to the columns, resulting in a virtually a monolithic frame. Faced externally with large storey-high concrete slabs, and internally with interlocking foamslag blocks. Internal partitions are constructed of breeze blocks finished in plaster, as is the foamslag internal cladding. The floors are constructed of pre-cast concrete flooring units, with timber flooring on timber runners.

Due to both the speed of construction and the quality of production, over time the PRC deteriorates, particularly at construction joints and junctions between components, with a gradual reduction in structural effectiveness. This resulted in the Orlit designated as defective under the Housing Defects Act 1984, and hence a majority of mortgage lenders will not give any form of mortgage on them.

Phoenix
The Phoenix, designed by Laing and built by themselves as well as partners McAlpine and Henry Boot, it looked much like an AIROH with a central front door, but far less aesthetically pleasing. A 2bedroom in-situ preform design with steel frame, asbestos clad walls, and an innovative roof of tubular steel poles with steel panels attached. Like all designs, it came pre-painted in magnolia, with green highlights on frames and skirting. Phoenix prefabs cost £1,200 each constructed onsite, while the specially insulated version designed for use on the Isle of Lewis in the Hebrides cost £2,000.

Reema
Reema houses are built from large-scale (nominally single storey height) precast reinforced concrete panels, themselves made in factories, before construction is enabled onsite. Reema houses come in two forms:
 * Reema Conclad
 * Reema Hollow Panel

Due to structural degradation and the use of asbestos in the wall and roof insulation, both are difficult to obtain a mortgage on today. The Reema Hollow Panel is listed universally as defective after a Government sponsored investigation and the subsequent Housing Defects Act 1984, while the Reema Conclad is often mis-recognised as a Hollow Panel.

Swedish
Between September 1945 and March 1946, Sweden exported 5,000 prefabricated houses to England and 2,100 to France. The design was adapted by the MoW from a standard Swedish kit, with the all-timber houses arriving in flat sections, and then stored at the docks for allocation, often to rural areas in support of farm workers. The first of these houses were built at Abbots Langley, Hertfordshire, in January 1946. The Swedish Government gifted 100 timber-framed houses to Scotland, which were erected in two locations in Edinburgh.

Tarran
The Tarran was designed by building firm of Robert Greenwood Tarran of Hull. A wooden frame designed bungalow, over clad with precast concrete panels. 19,014 Tarrans were erected under the Temporary Housing act, but one- and two-storey variants were built in some numbers afterwards.

Uni-Seco
Produced by the London based Selection Engineering Company Ltd, the three versions of the Uni-Seco were largely erected in London and the southeast. A 2bedroom flat-roofed bungalow, it had a resin-bonded plywood timber-frame with asbestos wall sections, it was based on a military wartime office design. With dimensions of 23 ft by 19 ft, the first two versions included the MoW standard kitchen/bathroom service unit, plus a lounge; Mk3's had a central entrance over the original side door. Uni-Seco had appointed in 1943 the Czehzolvakian emigre George Fejer as an industrial designer, who on a part-time basis helped out with their kitchen design. Fejer later worked with Arthur Webb and George Nunn at Hygena to create the UK style of fitted kitchen, based on the principles of the Frankfurt kitchen. Approximately 29,000 Uni-Seco units were constructed. The Excalibur estate in Catford, London Borough of Lewisham is the UK's largest residual estate of prefabs, presently consisting of 187 Uni-Seco bungalows.

Unity structures
Unity Structures were a construction company based in Rickmansworth. Using a common storey-level precast reinforced concrete panels, they produced various updated versions of their bungalow and twin-storey house variations. Using metal bracing within the cavity and metal joists connected at column joints, the PRC columns act as mullions. Copper straps tie the inner panel to outer PRC panel on earlier variant, while later the copper strap fixed to column holding just outer PRC cladding panels.

Although the design incorporates significant steelwork resulting in fair current structural condition, the concrete used in casting is decaying, and resultantly leaks chlorides. This results in internal staining through panel joints, and corrosion of the metal reinforcing and straps.

A Unity structures bungalow originally located in Amersham is preserved at the Chiltern Open Air Museum.

Wimpey no-fines
George Wimpey & Co. being a house builder, focused on both design but also speed and ease of construction. Their method used "no-fines" concrete, the composition of which used no fine aggregates. Using huge reuseable moulds, they were held in place as the concrete for the entire outer structure was poured in one operation. The ground floor was also concrete, while the first floor was made of wooden floorboards. Interior walls were a mixture of conventional brick and blockwork construction. Wimpey's design was particularly successful, resulting in many thousands built, and still occupied today.

Other types
There are Hamish prefabs (types 1 and 2), the Duplex Sheath prefab, the Bricket Wood Special prefab, the Blackburn Orlit prefab, and even a pre-fabricated gem known as the Foamed Slag.

Programme
The MoW built a small estate off Edward Road, Northolt, in 1944 to demonstrate to the construction industry, parliament and the media that the principles of their standards, and show that houses and flats could be built of concrete as well as brick. The highlight of the show was the live construction over 2 days of a Sir Frederick Gibberd designed BISF, under the watchful 24-hour eyes of the media.

The MoW then held a public exhibition of five types of prefab at the Tate Gallery in London, in 1944:
 * Two timber framed designs, the Tarran and the Uni-Seco
 * One steel-framed with asbestos panels, the Arcon
 * One aluminium prefab, made from surplus aircraft materials, the AIROH

This proved so popular, that the Tate held two follow up exhibitions in 1945. In April 1945, in a public relations exercise, an Arcon was completed and handed over to its new occupants by 22 men in under eight hours, and in May an AIROH was erected on a bombed site in London’s Oxford Street in just four hours.

While the cost of the prefabs was met directly by the MoW, the sites and utility infrastructure costs were the responsibility of the local authority. The 1944 Act had envisaged problems in obtaining access to sites quickly and hence slowing the programme, and so gave councils the authority to claim sites where two or more prefabs could be constructed. Councils were also given power over the site once identified, even before purchase was completed. The programme delivered quick housing, with properties going up at the rate in some authorities at the rate of 1.75 units per site per day, and the 100,000th house completed in January 1947 in Clapham, South London.

However, the cost of the programme at £150m met with opposition at many levels, both politically and economically. In August 1945 the Portal was abandoned for lack of steel, while the Uni-Seco was effectively stopped from production from the middle of 1946 through lack of supply of wood. It was stated that both the Arcon and AIROH were above budget: the British prefabs in both manufacture and construction costs combined turned out to be more costly than traditionally built brick houses, while the American sourced units were cheaper. The population allocated prefabs were also concerned that prefabs were a permanent over a temporary solution, with the postwar radio comedy Stand Easy! with Charlie Chester's creating popular skit-chants on the subject, including: Down in the jungle, Living in a tent; Better than a prefab, No rent! As the economy began to recover, the cost of the unwanted post-ware excess production reduced and hence costs of manufacture rose sharply. When the Chancellor allowed the pound to freely float against the dollar from 1947 onwards, a programme costing 60% of government income was severely cut back.

Total production
Production of the major types for local authorities continued until 1947, but only 170,000 of the 500,000 units promised were completed by 1951, when Churchill's new Conservative government made a promise of 300,000 new houses in partnership with the private sector:

NOTES:
 * LS - Precast Concrete, Large Slab
 * PP&P - Precast Concrete, Pier & Post

Residual housing stock today
The strength of the post-ware temporary prefab house - fast construction over an aluminium, steel or wooden frame - is today its weakness. The properties were only designed to last 10 years, and so some of the quality standards were not as high as they would have been should a longer life have been envisaged. Secondly, the quality of metal production then was not as good as it was now, but it should be remembered that in only the previous few years British manufacturing plants had become adapt at producing a consistently high quality product for the war effort, and so standards were consistent.

The quality of a steel framed prefab house, which can be suffering from rust, or a wooden house from rot, can be found in the footings of the structure where it meets the foundation slab. With checks undertaken by a qualified and certified housing surveyor, the structural integrity of the house can be quickly ascertained through exposure of the footings: if they are not rusty or rotted, the house is normally structurally sound.

The second problem with non-refurbished houses is the use of asbestos in the original construction, particularly in the roof structure. Again, a qualified surveyor should be able to ascertain if asbestos is present, what type, and how to address its removal. There are a number of central and local government grants available for domestic asbestos removal which should cover most of the cost.

The third problem with the survival or prefabs in the 21st century is that of style. Never seen as aesthetically pleasing, the tight building regulations meant they also came with reasonable sized rooms and gardens. Modern house construction can create around 35 living spaces per acre, while often the prefabs will be sat on site layouts of less than 20. This, together with the age of the properties, makes redevelopment of mass prefab sites a distinct advantage to councils and housing associations. Hence, every year since 2000, the number of prefabs remaining has approximately halved.

Preservation
Bristol has one of the largest remaining populations of prefab housing stock, and it also remains one of the most diverse. As a war time production centre for both aircraft, engines and explosives, it was easy to reach for Luftwaffe bombing, and hence had a large post-war need for new housing stock. There remain around 700 examples of Uni-Seco, Phoenix, Tarron and roll-topped Arcon MkV's. The stock diversity has resulted in English Heritage selecting 16 prefabs for Grade II listed building status.

The Excalibur estate in Catford, London Borough of Lewisham is the UK's largest remaining estate of post-second world war prefab houses, with 187 Uni-Seco wooden frame bungalows plus a flat-roofed prefab church. While residents fought to save the entire 187-unit estate, English Heritage wanted to save 21 examples, and the council which still owns 80% of the properties wanted the ability to demolish the whole estate. In September 2009, the Department for Culture, Media and Sport agreed to GradeII list six of the least altered properties. Similar debates have resulted in the listing of 16 Phoenix prefabs in Wake Green Road, Hall Green in Birmingham; and two in Doncaster.

Approximately six prefabs have been extracted from site for preservation, including one AIROH at the Museum of Welsh Life at St Fagans. An Arcon Mark V from Yardley in Birmingham is now preserved at the Avoncroft Museum of Buildings.

Audio/visual

 * AW Haksley Prefabs for Northern Ireland from archive of British Pathe
 * Lorry leaving the factory of AW Hawksley with an export house
 * Online MSPowerpoint slide show, showing reconstruction process on a Unity Structures Mk1 house

Category:Public housing in the United Kingdom]] Category:House types in the United Kingdom]]