The Grandmasters’ Crypt is a unique space underneath the presbytery and the main altar of the Co-cathedral. It is a world‐class artefact with beautiful frescoes and the ambitious objective of the intervention was to control the internal microclimate within the crypt. The target relative humidity and temperature needed for the preservation of the frescoes simply do not co‐exist in nature. Artificial means of control were essential and these are made possible by technological advances in microclimate control. Our brief was to find a solution to seamlessly and sensitively integrate the technical requirements, arising from the building physics, within the fabric of the Crypt, the Main Altar directly overlying the Crypt, and the secondary spaces behind the main altar, which extend from altar level to roof level, without in anyway compromising a historic national monument.
Our office was responsible for the overall design and execution of the project, bringing together the necessary expertise to identify the best possible and least intrusive routes for mechanical equipment, ensuring that the interventions were both achievable and sustainable. This meant, at times, incredibly complicated operations to hide ducts and wiring without intervening on the fabric and finishes. The chosen equipment was custom made and consisted of a sophisticated automated environmental control system, responding effectively to the fluctuating weather conditions without the need for constant manual adjustment. The system is controlled remotely from any mobile phone.
The design included a viewing gallery and a door to the crypt; the door is a custom curved glass door which allows visitors to safely view the crypt, since it has been closed to public viewing for the past fifteen years, and which allows access for special occasions and restoration works. Incidentally, the door design, which used the maximum width available, was put to good use is December 2021, when the Crypt was chosen as the final resting place of Fra Matthew Festing.
The original altar of the opulent St John’s Co-Cathedral was simple and made of stone, and its exact position at the very back of the presbytery has been located following works on the environmental system of the underlying crypt. These led to the unearthing of the altar, dating back to 1577. The two stone steps leading to the stark and small stone altar and the simple balustrade are now visible through glass at the far end of the presbytery.
The project was undertaken over a five‐year period, in collaboration with Galea Curmi Engineering, Bill Weedman, Bajada New Energy, Agius Stoneworks, as well as the very dedicated staff of the Co-Cathedral, under the guidance of the curator, Ms. Cynthia de Giorgio.
Some imagery was kindly provided by: St. John’s co-Cathedral Foundation.
Click here to view competition submission document to Din l-Art Helwa.
