During the 19th century Melbourne almost certainly imported more prefabricated buildings (then known as 'portable' buildings) than any other city in the world. Some - like Captain Lonsdale's cottage, made in Sydney in 1837 by the Royal Engineers, and others brought by private settlers from Van Diemen's Land - were manufactured in other colonies. Others came from Great Britain, the most interesting from the major London prefabricators, Peter Thompson and Henry Manning. Thompson's were generously proportioned, spreading houses, like the surviving Woodlands at Tullamarine (1841). Manning's were based on an ingenious system of standardised panels, exhibited (now largely in replica) in La Trobe's cottage Jolimont (1839).
The importation of timber houses virtually ceased during the depression of the early 1840s, but from late 1852 revived with the stimulus of gold. The majority of the imports were still of timber. An increasing proportion, made of meranti and dedaru (commonly referred to as 'cedar' and 'teak'), came from Singapore, and others from India, New Zealand, Germany and elsewhere in Europe. But there were now many other materials and systems: 'paper' (or papier-mâché, on a timber frame), portable brick (a tile-hung timber frame), slate (in large panels), zinc (in sheets on a timber frame, tensioned through with wrought-iron rods) and, most of all, iron in all its forms. Stimulated by the Californian gold rush of 1849-50, British manufacturers of iron buildings were quick to exploit the new Australian market.
Iron buildings ranged from tiny one-room corrugated-iron cottages with earth floors to generous villas and public buildings of plate iron, like Tintern, Toorak, by W. & P. McLellan of Glasgow, and the churches and other structures of C.D. Young, also of Glasgow, but soon of London. Corrugated-iron buildings, which at first were not necessarily galvanised, came also from C.D. Young, but more commonly from Samuel Hemming's giant factory at Bedminster, Bristol (houses, churches and shops), from E.T. Bellhouse of Manchester, whose patent cast-iron stanchions were shaped to fit the corrugations (houses, warehouses and G.S. Coppin's Olympic Theatre), from Francis Morton of Liverpool and London (especially schools), from G.H. Porter of Birmingham (schools and industrial buildings), and from Edwin Maw of Liverpool (classically pilastraded churches and warehouses). Colonial architect Henry Ginn was moved to design iron houses for the use of public servants. Ordered at great expense from John Walker, they arrived much later than envisaged. Identical houses, possibly for the use of the military, were obtained from Benjamin Walmsley of London.
In 1853 (at a time when a minimum cottage might cost £10) the colony received a total of 15 960 wooden-house packages of a total value of £246 371, or nine times that of the previous year. The figure was made up of £123 538 from Great Britain, £828 from British colonies in North America, £100 014 from British colonies elsewhere (of which Singapore, Van Diemen's Land, New Zealand and New South Wales were probably the most important), £20 981 from the USA (perhaps re-exports from the glutted Californian market) and £1110 from foreign states. In addition there were iron buildings amounting to 6369 packages with a total value of £111 380. The large majority of these, worth £109 740, were from Great Britain; those from other British colonies amounted to £1240, and those from the USA to £400. There were also 148 iron houses worth £1050 exported to other colonies, which seems strange unless the figure includes all buildings that left the Port of Melbourne, and hence those sent to Geelong or to the Ballarat goldfields by way of Geelong.
Although demand dropped sharply after 1853, for the rest of the century a trickle of mainly larger and in some cases very interesting buildings continued to arrive. These included Elford's patent portable houses of Californian redwood. Locally fabricated schoolrooms and lock-ups were generally destined for the country rather than for Melbourne. Police Commissioner Standish discussed with the government architect, William Wardell, the possibility of importing the 'Maison d'Abri' of W.H. Lascelles of London, and Lascelles's proposals survive on file, though they were never implemented.
The 1890s depression hit prefabrication harder than most other sectors of the building industry, and it did not really re-establish itself until World War II. After the war many timber buildings were imported from Western Europe, and others, such as the Bristol classrooms, from converted armaments factories in Great Britain. Locally the munitions factory at Holmesglen was first leased and then bought by the Housing Commission of Victoria and inexorably churned out the precast walls and other units for public-housing projects.