Another day. Following on from the thread about the Riversdale Demonstration Houses, here’s another bunch of inconspicuous-looking municipal houses in Edinburgh which once again pose the question of “well, what makes these so special then?”. This post will endeavour to answer that.

This is just one little corner of the large Lochend housing scheme, which was developed in the mid-1920s as a big showpiece by the Edinburgh Corporation. The Corporation purchased the 170 acre Lochend estate from Morton Gray Stuart, 17th Earl of Moray, in 1923 for £37,500 (£2.9M today). Central government subsidies in place at the time encouraged the use of “non traditional construction” techniques, to try and deal with post-war shortages of skilled trades labour and an economic downturn that put many men employed on labouring out of work. Edinburgh Corporation was quick to embrace both the money and the new techniques required to access it.

The first houses that went up at Lochend were of the Airey Duo-Slab type, a mix of pre-cast concrete slabs (which apparently made use of waste rubble from the construction of Portobello Power Station) and poured concrete.

At a ceremony officiated over by Lord Provost Sleigh, Labour MP for South Ayrshire and Lord High Commissioner to the Church of Scotland, James Brown MP, laid a foundation stone at a Duo-Slab house on May 27th 1924 (although construction had actually started in January).

Edinburgh Corporation ended up being very pleased with these houses and they would go on to become the prevalent type at Lochend, with something like 1,000 built (I haven’t counted them all!) There are Duo-Slab cottage flats at Restalrig Square, but those aren’t what this thread is about, there’s something else too. So if these other houses aren’t Duo-slabs then what are they? Well, one of them is a slight give-away as it’s different from the rest; strikingly so. This house is strikingly modern, with a flat roof, overhanging eaves, no ornamentation and chimney flues running up the façade.

This house is very conspicuous – Edinburgh’s City Architects were rarely radical when it came to style and even the thoroughly modern (in construction terms) Duo-slab houses were conservatively traditional in style; they had a mock-classical porch (pre-cast concrete of course), 4-over-2 sash windows, tiled hipped roofs and traditional placement of the chimneys. No, what we are looking at here is a different, radical new construction technique, one imported from the continent. This is a Corolite House and is basically a copy of the Dutch Korrelbeton houses of the early 1920s.

Korrelbeton translates from Dutch as – approximately – “granular concrete”. It was a “no-fines” technique (i.e. no fine sand or ash to fill in the gaps between the aggregate) but instead of gravel as an aggregate it used crushed waste brick, clinker or slag. This made it lightweight – it was 25-50% air pockets. It was also cheap, as it was mixed in the very lean ration of 1 part Portland Cement to 9 parts aggregate (which was recycled waste materials). The end result was both well insulated and breathable, so it didn’t suffer from two of poured concrete’s biggest drawbacks when it came to house building.

The Dutch developed Korrelbeton around 1919 and had been using it for 5 years when a visit was made by the British Housing Commission. Suitably impressed and interested, a British company was set up – the Corolite Construction Co. – in London to import this technique for housebuilding. Edinburgh’s City Architect, Adam Horsburgh Campbell, took a particular interest in what was going on in the continent regards housing and was either part of that delegation, or made a follow up visit of his own. In Jan. 1925, the Corporation accepted an offer from the Corolite Co. to built 52 experimental houses at Lochend to demonstrate the technique.

Thirteen blocks of 4-house cottage flats (mid-density, 4-in-a-block houses, with 2 flats upstairs and 2 downstairs, all with their own external entrance doors) were to be built. Six were of the “Dutch” style, with poured Corolite flat roofs, at £420 per house. Seven were of a more traditional style with a pitched, tiled roof, costing £440 each. These houses were eligible for £9/house rent subsidy, so saved the Corporation money.

The flat-roof type have overhanging eaves and the distinctive external chimney flues running up the facade. All except one of the 6 were re-roofed and reclad during the 1990s or 2000s, when rather odd-looking porticos were added. I’m not sure how one survived in its original form.

The other seven blocks were built with pitched roofs that had a reduced overhang and did not have the external flues or the central 3 windows recessed. They also got those same porticos during modernisation, so are visually quite similar – but not identical to – the refurbished flat roof houses.

These were amongst the first Corolite houses completed in Britain (they may be the first completed scheme) and were certainly the first in Scotland. On a visit to Scotland in June 1926, Prime Minister Baldwin said he thought them “quite agreeable to the eye“, “quite reasonable” and “wished [we] had more of them“. Baldwin’s government had announced a £40 per-house (about 10% construction costs) subsidy for the use of Non-Traditional construction, for the first 4,000 such houses built by local authorities in Scotland. While many authorities resisted this temptation as they did not like the terms, or care for non-traditional construction, others such as Edinburgh raced to try and build such council housing under subsidy.

In December 1925, the Edinburgh Town Council’s Housing and Town Planning Committee made a recommendation to the council that 500 further Corolite houses should be built at Lochend to capitalise on the subsidy. The Council however voted to turn down the recommendation by 35 votes to 20, after deputations from the building trade associations made representations. The £40 subsidy meant that only 10% of labour employed could be from skilled trades and the trades said it had been almost impossible to erect the Corolite houses with this workforce and keep to timescales. They also said that official figures for the number of men in the building trade that were out of work were wrong; they contended that they had better information as men out of work from one job to the next would sign on with their Union when in need of work, rather than with the Labour Exchange. Rather than being fully employed, the trades said that many men were unemployed; Edinburgh bricklayers were off working in England on public housing schemes due to the lack of work for them at home. Councillors asked about the shortage of plasterers; the plasterers’ trade representative pointed the finger at the building contractors. The trades said that building to more traditional construction practices would employ more men in the short term and the investment and would pay for itself in the long run by providing a better quality of house.

Dundee’s Housing Committee had also been unimpressed with the progress of Corolite houses, and had made that known in the papers. The Corolite Construciton Company were aggrieved at this and made their defence known in the papers too. L. J. Pond, their general manager in Edinburgh, defended the use of wallpaper on bare concrete (rather than plaster) as being the result of the 10% skilled labour cap and having to use an unskilled wall finish. He said that it was a “sanitary, durable and pleasing finish” and should not reflect on the house itself. Corolite also said that they could build good houses faster, and cheaper, and that if Edinburgh didn’t take them up on it then someone else would get the £40 per house subsidy instead and unemployed general labourers lost the chance of steady work.

In the end, neither Lochend nor Edinburgh (nor I believe, anywhere in Scotland) got any more Corolite houses. Airey won the contract to build lots more of their Duo-slabs at Lochend and the Second Scottish National Housing Company would build 350 steel houses for Edinburgh on Corporation land, before a return to more traditional construction for later phases. The Corolite Construction Company tried to flog their system to various other local authorities – Willesden Council in London built some at Brentfield and Manchester Corporation built a number that may total a few hundred – but overall they seem to have never found favour. The company moved on to other things and were last heard of in “Metroland”, advertising an estate of traditionally-built bungalows outside Berkhamstead in 1938.

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