The Water Tower/

Tonkin Liu

United Kingdom

Project Details



Norfolk / United Kingdom



Year (Design/Construction):

- / 2019

Area (Net/Gross):

160 m2 / -
Operational Carbon emissions

Operational Carbon emissions (B6) kgCO2e/m2/y:

Embodied Carbon emissions

Embodied Carbon emissions (A1-A3) kgCO2e/m2:

  • Sophisticated and unique re-use of existing structure.
  • On site materials such as tie rods were also repurposed to help reduce the total embodied carbon.
  • Natural materials such as timber are used where possible to improve the buildings environmental performance.

The historic village of Castle Acre is home to a ruined Norman Castle, a ruined 11thC Priory, a ruined Bailey gate and a ruined steel Water Tower. The Water Tower had been relocated from a local airfield after the war and had become a popular landmark with villagers, many of whom had climbed it during their youth. Bidding against scrap metal dealers, the tower was bought by the client in an auction. As part of the living history of the village, the disused structure’s preservation and reuse as a home drew great support from the local community.

The steel tank has become a living room, the steel frame has been infilled to provide sleeping chambers with a ground floor entrance and recreation area and a new tower has been added for access and to stabilise the delicate structure that swayed in the hilltop wind.

The rusty panelized steel tank has been retained and transformed with a panoramic window. Above and below the ribbon window steel trusses work in tandem with the existing steel panels to open the tank to an expansive view of the flat horizon. The support for the upper trussed panel is disguised by the frames of the opening portions of the ribbon window. A single skylight surrounded by mirror brings light from every direction into the living dining and cooking space.

Below the tank the existing steel frame structure is infilled with a prefabricated cross laminated timber structure. The timber cube like sleeping chambers are fully glazed on the north elevation to minimise light pollution to the village to the south and to overlook a vast field of barley that becomes a vast rural phenomenon as it is seen from above as it sways in the wind. The tall chambers that correspond to the frame’s proportions also contain a washroom and wardrobe with a mezzanine over. Small windows to the east and west provide cross ventilation and views over the landscape.

A bridge connects the sleep chambers to the cross laminated stair tower. The bridge is fully glazed to its sides to connect the occupants to the treetops of the line of trees that extend to the east and west. The bright and open space feeds natural light into the height of the enclosed stair tower.

The cross laminated stair tower has a castle-like cantilevered cross laminated stair that acts as a compression spiral as found in a seashell. The compression spiral delivers wind loads to the foundations and minimises the thickness of the CLT walls. From below the double tread spiral can be seen leading towards an ovoid skylight that fills the dark vertical shaft with top light.  The soft light illuminates the rusty iron balusters that have been formed from recycled tie rods that pulled together the sides of the water tank. The combined strength of timber spiral and shear walls form a rigid structure that lends stability to the existing steel frame structure as it adds lateral stability when it connects to the existing tank.


Architect: Tonkin Liu

Project Architect: Alex Woolgar

Structural Engineer: Rodrigues Associates

Services Engineer; Integration

Project Manager: Dennis Pedersen

Principle Contractor: MNB Services

Photographer: Dennis Pedersen

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