36 C O N T E X T 1 5 5 : J U L Y 2 0 1 8 DAVID ANDREWS Crittalls and metal windows Metal windows can be successfully overhauled, redecorated or, sometimes, remade: their manufacture and use is a significant chapter in 20th-century construction history. Windows are big business, as relentless advertis- ing reminds us. That is because they are one of the most vulnerable parts of a building, and as such present problems for those working in conservation. ‘They are just Crittalls’ is the sort of dismissive remark that might be heard when considering a building’s significance. Metal win- dows, the eponymous Crittalls, tend to be seen as rusty, draughty, ill-fitting and unlovely, not worth defending. But their manufacture and use is a significant chapter in 20th-century construc- tion history, 1 and in need of assessment. In 1849, Francis Berrington Crittall from Kent bought an ironmonger’s shop in Braintree, north Essex. He expanded the business, benefiting from the demand from agriculture, local indus- tries such as Courtaulds andWarners, and from improvements to drainage, plumbing and street lighting. Under his son, Francis Henry Crittall, the company took on an increasingly wide range of metalwork such as roofs, bridges, railway fix- tures, and fireproof doors, as at Ogdens Tobacco Factory in Liverpool. Among this work, windows began to figure prominently, partly through collaboration with a prominent local builder who specialised in churches, and partly through popular dissatisfaction with poorly maintained sashes. This business became so successful that in 1889 it was split off from the ironmongery shop. Proximity to London was also an advantage, early commissions including the National Gallery, the Royal College of Music, the Public Record Office and the House of Commons kitchens. A London office was opened in Finsbury Square in 1904, by which time the company employed 500 people. Metal windows had developed as opening casements in wood frames. Traditionally they were made of flat strips of wrought iron to which glazing was attached by rivets. Crittalls were able to take advantage of the introduc- tion of mild steel with the development of the Bressemer process from 1855 to manufacture rolled-steel sections quickly and easily to the required profiles to form windows. This process was subject to continual improvements. Brazed corners were succeeded by dovetail-jointed and then by welded ones. In 1905, Crittalls acquired rights to the Fenestra Joint, in which glazing bars were threaded through one another rather than mitred, making them stronger, with the possibil- ity of creating much larger areas of glazing. FH Crittall’s son Walter Francis, known as ‘Pink’, who had studied at St JohnsWood School of Art, set about simplifying the window sections, lead- ing to the development of the Universal Section in 1909. This superseded all the earlier profiles, becoming the industry standard and facilitating mass production by semi-skilled labour. WF Crittall’s interest in art and design was to have an important influence on the company, ensuring it was abreast of the latest trends in 1 Carpenter, R (2007) Mr Pink: the architectural legacy of WF Crittall , Essex County Council; Crittall, WF (1953) A Metal Window Dictionary , Curwen Press A Grade II listed, semi- detached pair of ‘unit- build’ houses. These are the best-preserved (and recently conserved) of the properties on the Crittalls Clockhouse Way estate, designed by CHB Quennell and built in 1918–20.