Whispers from the past echo within these ancient timbers. We stand before the Harmondsworth Great Barn. This is no ordinary barn. It is a survivor. It is a testament to medieval craftsmanship. This magnificent structure is the largest timber-framed building in England.
Let’s journey back to the early 15th century. Imagine William of Wykeham, Bishop of Winchester. He commissioned this barn. Winchester College needed a place to store grain. The Harmondsworth Great Barn was the answer.
The barn’s vast size is striking. It measures 192 feet long. It is 37 feet wide and 39 feet high. Inside, twelve bays stretch before us. Three doors punctuate the east side. Wagons once entered here filled with harvest.
Notice the exterior. Weatherboarding protects the barn. A hipped tiled roof crowns it. Originally, the barn had two wings. The north wing was moved in 1774. It was rebuilt in Heathrow.
Look closely at the timbers. Ninety-five percent are original. English Heritage calls it a supreme example of late-medieval craftsmanship. It is a masterpiece of carpentry.
Medieval barns like this had longitudinal frames. Two rows of posts support the structure. Internal braces act like buttresses. They strengthen the barn against wind. This creates the barn’s distinctive interior. Beams and braces form a lattice supporting the roof. The same techniques used in cathedral construction were used here.
Feel the texture of the oak posts. They are about 14 inches square. They rest on Reigate sandstone blocks. Builders used axes, adzes, and saws to shape the wood. Marks from these tools are still visible. Roman numerals scratched on the joints indicated where timbers fit together. Some posts were made from huge trees split in two. The wider bottom of the tree supports the roof beams. Some unused holes suggest reused timbers.
The aisles increased the barn’s width. This created more space for threshing floors. Harmondsworth Great Barn has three threshing floors. This allowed more grain to be threshed at once.
The exterior boards are a mix of oak, elm, and softwoods. Some are replacements. Notice the lighter colored boards on the south end. These resulted from repairs after a 1972 fire. The roof has 92 tile courses. Originally, oak pegs held the tiles. Now, galvanized nails replace decayed pegs.
The floor was originally hard-packed flint gravel. Iron panning held it together. Later repairs used brick, tile, and cement. The west side exterior shows how the original floor looked.
Architects have long admired the barn’s design. Sir George Gilbert Scott sketched it in 1850. He used it for his Christchurch Cathedral proposal in New Zealand. Basil Champneys drew inspiration for Mansfield College’s library. Ernest Gimson’s Bedales School library also reflects the barn’s influence.
The manor of Harmondsworth belonged to King Harold before 1066. William the Conqueror seized it. Later, William granted it to William FitzOsbern. In 1391, William of Wykeham acquired it. He gave it to Winchester College.
Records show a Great Barn existed here as early as 1110. By 1426, Winchester College commissioned a new barn. William Kypping and John atte Oke obtained timbers. The architect may have been William Wyse. Carpenters from Ickenham and Uxbridge also worked on it.
In 1544, King Henry VIII took the manor. Later, he granted it to the Paget family. The Ashby family owned it in the 20th century. Peter Purser bought the farm in 1950. It was already a Scheduled Monument. It gained Grade I listed building status in 1950.
A German V-1 bomb damaged a nearby barn during World War II. The Harmondsworth Great Barn only lost a few tiles. Poet John Betjeman called it the Cathedral of Middlesex.
In 2006, the property development company went bankrupt. Property speculators bought the barn. They hoped for compensation from Heathrow Airport expansion. The barn fell into disrepair. English Heritage intervened. They carried out repairs and purchased the barn in 2012.
The Friends of the Great Barn group now manage it. It is open to the public from April to October. This barn stands as a symbol. It represents the rural economy. It shows the immense investment in craftsmanship.
Standing here today, we can appreciate the Harmondsworth Great Barn’s grandeur. It is a testament to human skill and enduring history.