Terraced housing combined to make a unique succession of urban communities, villages almost, that contrasted sharply to nucleated urban development elsewhere. About 40 per cent of homes in Wales are terraces, and this will still amount to 28 per cent of our housing stock by 2050. This inheritance should be enthusiastically celebrated, rather than seen as an incubus or hangover from the industrial age. As the architect Andrew Sutton has written, 

'the geography of the valleys' terrace housing clinging to the hillside meant that Wales never had the same density of back-to-back slums as there were in some English cities, and so they've remained desirable places to live with strong community spirit.... Indeed, if you were starting with a blank sheet and looking at ways to build on the steep slopes of south Wales, even today you probably couldn't come up with an idea better suited than the terraced house.'

End quote. There is much more than utility in favour of traditional Valleys housing, however. According to the architect Peter Ireland, and quoted in The Guardian:

'The most sustainable thing we can do is to not build new stuff.... I often say to a client, everything is an asset until we prove it otherwise.'

While I have not found any estimates for embedded carbon in terraced houses, it has been estimated that an old flour mill in Sydney saved 21,000 tonnes of carbon dioxide by avoiding demolition to become 47 studio flats, equivalent to keeping 5,000 cars off the road for a year. The Green Building Council of Australia encourages this approach on reuse and retrofitting. It is developing a building retrofit toolkit to improve energy efficiency, resilience and sustainability. The Welsh Government could usefully calculate the embedded carbon in the pre-1919 housing stock. We also need to restore the once commonplace skills and knowledge base necessary for the correct repair and maintenance of traditional buildings, such as the Valleys terraces. 

While we inevitably think of coal when talking about Valleys housing, there is, in fact, a deeper heritage. The iron towns of the Heads of the Valleys, most notably Merthyr, set the trend for terraced housing. By the beginning of the nineteenth century, Merthyr had become the largest town in Wales, and by 1851 its population of 46,000 was twice that of Swansea and two and a half times that of Cardiff. The surviving houses of this period are every bit as important architecturally as the Royal Crescent in Bath, and I really do believe that. Chapel Row, Georgetown—you're now seeing some of these images on the montage—Coedcae Court, for example, again in Merthyr, roughly date from 1830. 

Even more remarkable is the survival of Butetown in Rhymney, again built in the early 1800s and described by John Newman in his magisterial volume, Glamorgan, in the Buildings of Wales series, as

'reminiscent of James Adam's Lowther Village, Westmoreland'.

Its simple and classic details are outstanding. 

It is apposite that, as we debate this unique heritage of Valleys housing, the Design Commission for Wales has today published a report on Merthyr, and I do encourage everyone to have a look at this. Based on the revival of Cyfarthfa castle and the estate east and west of the Taff, it sees this as an anchor project for a Valleys regional park. In time, this could become an extension of the World Heritage Site at Blaenavon. This is just the sort of vision that we need, and it would combine perfectly with the reassessment of the value of Valleys housing to the image and contemporary culture of Wales. I congratulate Geraint Talfan Davies and his team for developing this exciting project.

The Welsh Government does share much of this ambition, and the work of the Valleys taskforce is promising. Certainly, its work to improve skills could be an excellent way to enable retrofitting schemes to be expanded, and many more traditional terraced homes to become energy efficient. Likewise, helping to ensure that the south Wales metro provides excellent public transport services to our Valleys communities is another way to see their revival. 

And we should not forget that industrial activity brought similar housing to communities in north Wales. On the montage is a photo of Nant Gwrtheyrn, which many Members will know as an innovative Welsh language and heritage centre. The village was built to serve the local quarry and was eventually closed in world war two. The cottages fell into disrepair and ruin before being restored with great skill and sensitivity more recently. And it's a wonderful example of what can be done with what seemed to be hopeless and derelict terracing. 

Finally, let me finish with an eccentric example, but it also contains, I think, a warning. The Valleys have a rich heritage, and perhaps this is no better demonstrated than in the round houses of Glyntaff, Pontypridd, built by the truly astonishing Dr William Price as part of his development of a druidic museum. The museum itself, unfortunately, which was a larger round house, was demolished in 1950, and it is a reminder of the care we need to take to cherish this architecture and inheritance. 

To conclude, it is time for us to appreciate the full value of the built environment developed in the nineteenth century. Much of it was humble, vernacular architecture, but always with the dignity that comes from the development of strong communities. The terraced housing in particular has stood the test of time and has served many generations. It is adaptable and sustainable because of its embedded carbon. Not only is it a heritage worth investing in, it is also a vital part of what makes Wales special and distinctive. Nearly all of the heavy industry that stimulated this, the greatest programme of building in our history, has gone. The houses, however, remain; let's celebrate this rich inheritance.