Fabric of the building

The Palace of Westminster was built in the mid-1800s as a state-of-the-art purpose-built home for Parliament. The architect was the renowned Charles Barry, assisted by Augustus Welby Pugin.

The oldest part of the Parliamentary Estate, Westminster Hall, was built by William Rufus, son of William the Conqueror, in 1099. Westminster Hall survived the fire of 1834, as did the early 16th century Cloister of St Stephen’s College and the 13th century Chapel of St Mary Undercroft.

The backlog of conservation work and repairs to the fabric of the building is largely a result of the difficulty of carrying out work around sittings of Parliament combined with decades of under-investment. Pollution and lack of maintenance is causing significant decay to stonework. The vast majority of the Palace’s 4,000 windows do not close properly, letting water in and heat out. Internal plumbing constantly fails and the cumulative effects of wear and tear are evident in all the principal spaces.

Time lapse footage of the refurbishment of Parliament’s cast iron roofs


The Palace was built using Anston limestone because it was cheaper and ideal for elaborate carving. However, the stone quickly began to decay and very little was done to prevent its decline during the 19th century. Some stone cleaning and restoration work was carried out in the 1980s and 1990s but there is still a huge amount of essential work to be done.

Internally, the original linings are Painswick and Caen stone, chosen because they were ideal for carving. Today, much of it is in need of cleaning or restoration due to wear and tear, leaking roofs, decaying windows and antiquated plumbing.


There are around 4,000 windows, from basic casements in rooms and corridors, to the ornate glass panels that allow light to fill the many hallways and chambers of the Palace. This vast amount of glass, much of it set in bronze framework, no longer provides weather resistance and is responsible for significant heat loss from the Palace.

Cast iron roofs

The cast iron tiled roofs were installed on wrought iron structures in the mid-1800s, and used innovative, leading-edge technology. They have never undergone major renovation or repair. Now, 160 years on, the roofs are leaking, causing significant damage to the stonework and historic interiors of the building. To avoid further damage to the fabric of the building, a phased programme of roof repairs is already underway to ensure the building is watertight before any major internal restoration and renewal work begins.


Fabric of the building