Trent Park Mansion House's Refurbishment

Trent Park Mansion House’s Refurbishment

30 July 2026

Previously dilapidated and unused, the Grade II listed Trent Park Mansion House has been transformed over the last five years into a fully refurbished set of upper-level luxury apartments and lower-level museum. Honouring the building’s rich past, the Trent Park House of Secrets Museum opened earlier this month whilst the final touches are being made to the apartments above.

Appointed to deliver civil and structural design on the project in 2021, EOC worked on the sensitive restoration of the mansion house and the additional storey extension roof.

Most recently used as a university campus teaching facility, much of the building’s historic fabric had been covered with unwanted modern finishes, hiding a wealth of intricate detail which has been painstakingly uncovered, restored and carefully repaired during the construction phase.

The refurbishment works included a new lift shaft has been threaded through the central corridor, providing suitable access to the upper floor apartments and an additional floor comprised of setback mansard roof has been added. The vertical extension retained all the historic attic steelwork, validated for the additional loading, alongside some areas which needed strengthening to achieve the new massing.

Some underpinning was required in the basement along loadbearing masonry walls to achieve new lift shafts, as well as progressing additional buried services and drainage runs. New, large, steel box-frames were used within the masonry spine walls to achieve the wide-open space required in the museum layouts at ground level.

Our expertise helped breathe new life into a building which was home to a secret intelligence operation in World War Two, learn more about the history of Trent Park Mansion House here: BBC News.