Building Materials Through Time: From Cob to Titanium

Start with the oldest idea: subsoil, water and straw built up by hand in courses without formwork. Cob walls are thick, load-bearing and monolithic, and in England's West Country, parts of Africa and the American Southwest they have survived for centuries when a wide roof overhang and a raised stone foundation keep standing water away.

Wattle and daub has been used since the Neolithic period. A woven lattice of wooden strips is plastered with wet soil, clay, sand and straw as infill inside a timber frame, and it gave English and German vernacular building its black-and-white half-timbered facades.

Firing clay in a kiln turned a soft earthen block into a strong, weather-resistant unit, a process dated to at least the third millennium BCE in Mesopotamia and the Indus Valley. By the early first century CE standardised fired bricks were being produced in quantity in Rome.

Quarried stone is the counterpart to made brick. Limestone is soft enough to carve when freshly quarried and hardens on exposure to air, which is why Egyptian and Greek builders used it for temples and European cathedral builders used it for tracery and sculpture.

Roman concrete, opus caementicium, paired a lime binder with volcanic ash from deposits near Pozzuoli and was refined from about the third century BCE. It made monumental unreinforced work possible, including the coffered dome of the Pantheon, and research in 2023 found that lime clasts react with water seeping into cracks and help the material heal.

Timber runs underneath the whole story, from medieval European timber-framed houses to Japanese post-and-beam temples and the balloon-framed houses of nineteenth-century North America. Softwoods such as pine, fir and spruce dominate framing, while oak and teak were favored for load-bearing frames and joinery.

Cast iron brought the industrial age into building. One of the first important projects was the Iron Bridge in Shropshire, opened in 1781 and made almost entirely of cast iron. It is strong in compression but brittle in tension, so it suited columns, ornamental facades and the mid-nineteenth-century cast-iron storefronts of New York's SoHo.

In his 1824 patent Joseph Aspdin named his invention Portland cement for its resemblance to Portland stone. Made by firing limestone and clay and grinding the clinker with gypsum, it displaced the older lime-based mortars over the nineteenth century and underlies essentially all modern concrete.

Wood was engineered as well as sawn. The first patent for glued laminated timber came in 1901 from Otto Hetzer, a carpenter in Weimar, Germany. Bonding layers of lumber produced beams and arches that span farther and curve, which allowed large clear-span gymnasiums, churches and exhibition halls.

Harry Brearley of Sheffield was seeking a corrosion-resistant alloy for gun barrels in 1913 when he discovered stainless steel. Its chromium oxide layer repairs itself, and it appears in the Gateway Arch in St. Louis and the crown of the Chrysler Building in New York.

Sir Alastair Pilkington and Kenneth Bickerstaff of Pilkington Brothers developed float glass at Cowley Hill Works in St Helens between 1953 and 1957, and it reached commerce in 1959. Floating molten glass on molten tin gives a flat, distortion-free sheet and became the base for essentially all modern architectural glazing.

End with a metal borrowed from aerospace. Titanium panels clad Frank Gehry's Guggenheim Museum Bilbao, completed in 1997, where the shifting silver-gold sheen of the curved skin became part of the building's identity, despite titanium costing more than steel or aluminum.