This thread is a bit of an A-to-Z of the different types of permanent, prefabricated, post-war housing built in Edinburgh between 1945-1950.

In the aftermath of WW2, hundreds of thousands of temporary, prefabricated houses were built across the UK, as part of a national crash-building programme to ease urban slum dwelling, replace war losses and provide housing for men returning from war until the construction of permanent housing could catch up with demand. In Edinburgh, some 4,000 temporary prefabs were built, of four types; AIROHs, ARCONs, Tarrans and Uni-SECOs. But prefab housing wasn’t just temporary, it was also for permanent construction. It was hoped that by mass-manufacturing standard designs of modern houses in factories, they could be rapidly built with limited skilled labour.

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A is for Aluminium. Some of the first permanent prefab houses ordered for Edinburgh were of the Permanent Aluminium or Blackburn Mk.II design. These were based on the AIROH (Air Industry Research Organisation for Housing) single-storey, temporary, aluminium cottages – of which some 54,000 were built – but with thicker walls and insulation, designed to last 60 years instead of the AIROH‘s ten. These were developed by the British aircraft industry as a way to find use for its skills and manufacturing facilities in the postwar environment, and to make use of a glut of scrap aluminium from surplus aircraft. This material has its advantages; it is light, strong, does not rust or readily corrode and – initially – readily available from scrapped aircraft. It took 2 tonnes of aluminium to build an AIROH house frame. So a single large fighter aircraft like a Typhoon give you all the aluminium for a house. The Blackburn Aircraft Company of Dumbarton got on board.

They have been described as an “airplane in house form“; manufactured in sections on an aircraft production line, in sections that could be transported by road, and assembled quickly on site by unskilled labour. They came pre-fitted with standard kitchens and bathrooms, all of which just needed connected together on site on a simple brick or concrete plinth. The problem for aluminium houses of all types was that the price of the material soon rebounded and they became very expensive to produce, but they filled a gap and were not the worst of the temporary prefabs by any stretch.

Edinburgh purchased 166 permanent Blackburn Aluminium Houses; 145 for the Craigour Scheme in Moredun and 21 for Muirhouse.

These houses are quite easy to identify, as they are small, detached cottages with 3 regularly-sized windows and an offset front door. The shallow-pitched roof has a small brick chimney stack and was originally aluminium sheeting. There were 3 overlapping joints on the façade where the 4 prefabricated modules were joined together. These houses were quite popular, they sit on large plots and have big gardens. They are detached and the frames have not been subject to corrosion. Many have been insulated, re-clad, re-roofed and even extended. Some have been demolished and new houses built on their plots.

B is for BISF. These houses were named after their manufacturer and designer, the British Iron and Steel Federation. The house is of a conventional, semi-detached design, but uses a steel frame with steel window and door surrounds and Critall-Hope steel framed windows. The lower storey was clad in render applied to a steel lath and the upper storey had steel sheeting formed to look like timber. Interior partitions were plasterboard or wooden fibreboard and insulation was glass fibre. Most have been stripped back to their frames, re-insulated and re-clad with pebble-dash, and given modern plastic double glazing units. The fibreboard walls were prone to damp and fire and most were replaced with plasterboard during refurbishments.

In Edinburgh, c. 300 of these houses were built in Southhouse / Buirdiehouse (1947) and Moredun / Fernieside (1949) Schemes and most (if not all) remain to this day. They are somewhat unusual in that they were always intended to be permanent, and have not suffered from the usual structural degradation and corrosion that have plagued other non-standard houses. As such they are one of the few prefab designs that have never been designated as defective (which means you can get a mortgage on one).

Useful identification features for BISF houses are that they are always semi-detached; they have a single, squat, central chimney on a pitched roof; the re-clad houses often have a mix of brick and pebble-dash cladding; the main ground floor window extends almost to floor level; and they lack the heavy reinforced concrete door and window surrounds of the concrete houses.

B is for Blackburn Orlit. These houses were a collaboration between the Blackburn Aircraft Company in Dumbarton and the Orlit Construction Company (see under O). They were designed in 1949 and used an improved, simplified version of the Orlit reinforced concrete frame and wall panel system, combined with the lightweight aluminium roof structure and pre-fabricated internal partitions covered in plasterboard, by Blackburn. Kitchens and bathrooms were also prefabricated “pods” produced by the Scottish Myton Company, based on experience with the Tarran temporary prefab houses. Four houses were built as a prototype in Clydebank in 1949, followed by 214 in 1950-51 on the Saughton Mains Scheme in Edinburgh, as semi-detached and terraces. Around 1,300 were built in total across Scotland.

These houses have the usual heavy, PRC door and window surrounds of Orlit houses and the irregularly-spaced concrete “quoins” on the corners. The ground floor front room window is deep (deeper than standard Orlits), but has often been in-filled with a shallower window. They have a shallow-pitched, gabled Blackburn roof (the roofs of Scotcon Orlits and those added to earlier Orlits are “hipped”) and lack the usual Orlit narrow, first-floor window over the front door. Instead they have 3 windows squeezed into the façade upstairs.

B is for Blackburn Mk.IV. Another collaboration between Blackburn and Orlit. These houses were of a more traditional construction, with walls constructed out of pre-cast “no fines” concrete blocks on a concrete slab foundation and Crittal steel-framed windows. I assume given Blackburn‘s involvement there were aluminium internal components used. You will find these in Edinburgh at the West Mains Scheme in Blackford,where 134 were built in 1951 as 4-in-a-block terraces. Nearly all have now been re-rendered, hiding their original concrete blockwork structure. Because they lack the Orlit‘s PRC frame and steel joints, they have not been classed as defective.

Identification features are the blockwork walls (where you can see them); the lack of the heavy, PRC door and window surrounds of most Orlit houses; the door surround has as small concession to detail (usually absent from such houses) with a moulding line around it; the central bay windows at ground floor level originally had a copper-sheathed roof.

B is for Blackburn Permanent. Also known as the Blackburn Mk.III, as the name suggests, this was a permanent house making use of Blackburn’s prefabricated internal partitioning and shallow-pitched aluminium roof structure, which was originally covered in aluminium sheeting. The form was basically the same as the Blackburn-Orlit house, but without the heavy PRC window and door frames and walls are traditional blockwork. Edinburgh built these as semi-detached and 4-in-a-block terraces, at Moredun in 1949 and the then Midlothian County Council as semi-detached houses in Currie in 1950.

Identification features are the shallow roof pitch, squat chimneys, and the strip of 4 windows with brick infill on the first floor. Again there is a very deep sitting room window. These houses are usually harled or pebbledashed.

O is for Orlit. The Orlit System was developed by the Czech architect Erwin Katona, a Jewish refugee who had come to London in the late 1930s. He developed a modular, pre-cast reinforced concrete (PRC) system of construction that could be built in a factory and rapidly assembled on site with limited and unskilled labour. PRC columns and beams slotted together to form the structure, in-filled with an interlocking system of concrete tiles. Floors and roofs were of concrete channels. The roof could be a flat concrete slab covered in bitumen paper or a traditional wooden, pitched structure with tiles. Windows were Critall steel-framed, set within PRC concrete frames of standard sizes. The Orlit System could build a range of buildings, from single-storey cottages and municipal buildings to tenement flats. Usually they were semi-detached houses though.

The System was meant to be for permanent houses, with a 60 year lifespan, but was unfortunately riddled with flaws and weaknesses. Over time, PRC deteriorates, particularly at construction joints and junctions between components, with a gradual reduction in structural effectiveness. It suffers from inadequate thermal insulation, as well as thermal bridging – making houses cold and prone to condensation on the walls. As early as 1949, people in Edinburgh were writing to the newspapers to complain about the flaws in brand new Orlit houses. The original Type 1 system was replaced with the Type 2 to try and remedy the deficiencies. By 1950, they had abandoned the pre-cast frame system almost entirely (except for the window surrounds) and moved on to modular concrete block construction, which eliminated the structural weaknesses at least! All Orlit houses built to the original Type 1 or 2 systems have been designated defective.

Orlits were popular with Scottish local authorities and set up a subsidiary – the Scottish Orlit Company – with its headquarters and factory in Sighthill. Around 6,000 were built across Scotland, of which half have been subsequently demolished. Edinburgh built around 668, 410 of which have been demolished. These were a mix of the usual 2-storey semis and tenement flats; all of the latter were built at Bingham and were demolished in 1985. 134 semis were built at Saughton Mains (in 1948) and 80 at Southhouse / Burdiehouse (in 1947), all of which remain. This post does not cover the later 1950s-built Orlits at Ratho Craigpark, Oxgangs Farm and Gilmerton Dykes.

The Orlit System evolved over time, and has a large amount of variety available due to the flexibility of the system, however the best things to look for are the heavy outlines of the pre-cast concrete window surrounds, the narrow windows over the front door and to the side, and the bulky outline of the original concrete flat roof slab to which the later hipped roofs were added to remedy the deficient nature of the structure. I believe all Orlit System houses built in Edinburgh were originally flat roofed.

S is for Scotcon Orlit. Scotcon (from Scottish Construction Company) were a subsidiary of the Scottish Orlit Company, formed expressly to undertake local authority housebuilding in Scotland. While much of their work was prefabricated tower blocks, they also built on the standard Orlit system. 296 Scotcon Orlit houses were built in Edinburgh in 1950-51, a mixture of semi-detached houses and 3-storey tenements. 126 have since been demolished, but 170 remain; in the Niddrie Marischal Scheme (tenements and semis); at Saughton Mains (only 3 semis, perhaps built as demonstration models given their proximity to the Scottish Orlit Co. factory at Sighthill); Dunsmuir Court in Corstorphine (tenements) and at Easter Drylaw (tenements).

Because they use the Orlit system of PRC beams and columns, with pre-cast interlocking concrete block walls and PRC window and door surrounds, they are designated defective. They have traditional timber-framed, pitched roofs.

Scotcon Orlits look like other Orlits, with the heavy PRC window surrounds, but that of the ground floor front room is much deeper. They have the trademark narrow window over the front door, and (where they haven’t been covered up with pebbledash), irregular concrete “quoins”. The “hipped” roofs were built as pitched timber and tile structures, so they lack the heavy slab of the early Orlits built with flat roofs (to which a pitched structure was later added).

The tenements can be recognised by the heavy PRC window surrounds, with the usual wide and deep front-room window, and narrow windows over the front door. All the Scotcon Orlit tenements in Edinburgh are 6-in-a-block. The ground floor houses have their own entrance doors to the side.

S is for Swedish Timber House. The Swedish government sold 5,000 flat-pack timber houses of a standard design to to the British Government after WW2. Half went to Scotland, particularly for rural housing, and the first 350 arrived as early as October 1945. Similar houses had been built in Glasgow in 1937 by the Swedish Government to demonstrate them to Scottish local authorities. 100 were gifted to Edinburgh Corporation by Sweden as a gesture of post-war good will, with 50 each erected in West Pilton and Sighthill under the supervision of Swedish foremen, as a mix of semi-detached and 4-in-a-block terraces. An additional handful were built by the SSHA at their Sighthill Demonstration Site.

Because they are of traditional timber construction with pitched, slate roofs, they have never been designated defective. Most have been externally insulated, and re-clad with harl or render, but some retain their original timber cladding.

The original tongue-and-groove timber cladding of thin strips, with those of the first floor overlapping the ground floor, are the best identification feature. They have a large front room window on the ground floor and a small canopy over the door. Most of those that still retain their timber cladding have been treated with dark brown or red preservatives, but originally they were brightly painted in cream. The roof is tiled and well pitched, with a single, central chimney to the front.

W is for Whitson-Fairhurst. These houses are named after their designers, W. A. Fairhurst and Melville, Dundas & Whitson Ltd. They were of a modular, prefabricated concrete system built by the Scottish Housing Group, a post-war conglomerate of housing builders who had pooled their resources to meet government and local authority contracts for mass construction. They use a system of PRC columns and beams to form the structure of the house, which are in-filled with an outer skin of brick and an inner skin of breeze blocks. Window surrounds and door frames are relatively heavy PRC structures. A traditional timber roof structure was covered in concrete roof tiles and they were harled or pebbledashed. 3,400 Whitson-Fairhurst houses were built in Scotland,. In Edinburgh they were only built in the Southhouse / Burdiehouse Scheme, where 100 semi-detached houses were built. They are designated defective.

At first glance they could be confused for an Orlit house, with heavy PRC window surrounds. The biggest difference is that the roof is of the gable-type (when seen from the front, the sides of the house are flat all the way to the top of the roof), not “hipped” as in Orlits (when seen from the front, the sides of the roof are pitched towards the top) The front window is much deeper and they lack the Orlit‘s signature narrow window above the front door.

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