Astley Castle in Warwickshire (UK) by Witherford Watson Mann is a restoration project that cleverly inserts a modern living house within the ruins of a 12th century English castle. Modern, intelligent materials combine with the metaphysical powers of ancient ruins in this intriguing tapestry of old and new. The project won the Stirling Prize in 2013.

Generations of vandalism, neglect and a devastating fire in 1978 left the Astley Castle in a ruinous state by the early part of this century. The scale and lack of surviving detail in the remains made the conservation or restoration of the castle to its original state impossible. Instead, architects Witherford Watson Mann aimed to restore the materials that were salvageable and fill in the remaining gaps with modern materials.

The first step was to clear the substantial amounts of rubble on site and make the premises safe. After years of exposure to the elements, the remaining walls were around 1m in thickness, up to 800 years old and in a very derelict and structurally unstable condition. The remaining walls that could be salvaged were stabilised using an almost invisible patented technical process called Cintec drilling whereby a hole is drilled into a wall and a stainless rod inserted. An expansive cementitious grout is pumped into the wall through the rod. The grout then slowly expands into all the voids and cavities in the walls, stitching it together from the inside.

After the remaining walls were stabilised, they formed two separate masses. To bridge and fill in the gap, two enormous concrete lintels were craned into position on site. Next, new walls were constructed with a modern brick that was selected for its tone, texture and non-standard dimensions that are sympathetic to the existing ancient masonry but create a crisp distinction between old and new. In addition, a number of joinery elements sit within the new concrete lintels and brick walls. Laminated wood beams create a new floor system and as a highlight, a new modern staircase was constructed out of oak wood.

The Astley Castle design and build shows that the renovation possibilities of historic buildings are much broader than one might think possible. The juxtaposition of old and new result in a romantic ruin with great, modern material details.