Caulmert’s structural and civil engineering expertise has helped transform a previously derelict Grade II-listed building into eye-catching affordable housing.
Plas Alltran, Holyhead, was listed as one of the ten most endangered buildings in Wales and England by the Victorian Society. In its long history, it had been used as a World War One first aid post, a soup kitchen, a 1930s boarding house, a dance school, a home for tuberculosis sufferers, and doctor’s surgery amongst other things.
Working in partnership with BTP Architects and Recclesia for client Cyngor Sir Ynys Môn, Caulmert’s services enabled the derelict building to be converted into four new one-bedroom flats as part of a £1.5m redevelopment over a two-year period.
The project team worked closely with conservation officer and Cadw to agree restoration methods and materials for the scheme.
Led by associate structural engineer Jonathan Parry, Caulmert’s activity included:
- Strengthening works to existing timber floors affected by fire damage and decay.
- Stabilising of the gothic gables and feature stonework at roof level to ensure long-term stability.
- Internal structural works for the proposed remodelling of the building, including new access stairs.
- Assessment of existing structural elements to be retained, including arch lintels above the windows.
- New foul drainage on the ground floor serving the new flats.
- Structural works to stabilise the external walls to the rear courtyard.
Jonathan said: “It was a real pleasure to play a role in the preservation of this important historical building in Holyhead, and to help convert it into social housing.
“Plas Alltran had been derelict for a long time, so it felt like a rescue job when we initially viewed the project, but together with BTP Architects and Recclesia, the team came together to produce a high-class finished product.
Andy (Kwok) Wan, director at BTP Architects, said: “Plas Alltran is a fantastic example of how careful restoration, mindful design and successful partnership working can come together to create sustainable, affordable homes.”
Founded in 2008, Caulmert is on track to meet an ambitious growth and development plan.
Its expertise in a variety of engineering, environmental, planning, and project management disciplines is supported by its use of Building Information Modelling (BIM) to ISO 19650 standard on many of its projects.





