Williams published a series of booklets on the living conditions of the poor and on building reform. He lamented the poor living conditions of miners, despite the fortunes made by the mine owners. Williams published a book, The Collier's House or Every Collier his own Architect, in 1893 (in English and Welsh) containing drawings showing improved housing for coal miners, particularly in the Welsh Valleys. He wrote More Light and Air for Londoners - the Effect of the New Streets and Buildings Bill on the Health of the People published in 1894, The Face of the Poor or the Crowding of London's Labourers in 1897 and The Labourer and His Cottage in 1905. Williams' cottage designs were unusual for the time in showing internal toilets, at a time when outdoor privies were the norm.
