CASE STUDY

FLAT HOLM ISLAND

Architecture | Quantity Surveying

PROJECT SNAPSHOT

PROJECT NAME: Flat Holm Island
LOCATION: Bristol Channel, Cardiff
COMPLETED: November, 2025
OUR ROLES: Architects & Quantity Surveyors
BUILDING TYPE: Heritage
CLIENT: Cardiff Council
PROJECT VALUE: £1.7m
PROGRAMME: 8 months
RIBA STAGES: 4-7
CONTRACT: JCT Intermediate

PROJECT SUMMARY

The Flat Holm Island Conservation Project focused on the preservation and restoration of two nationally significant heritage assets: the Grade II Listed Foghorn Station and the Scheduled Ancient Monument Cholera Isolation Hospital. The project adopted a sensitive conservation led approach to protect and preserve the historic fabric of both buildings while respecting their architectural historic significance and setting.

Works to the Foghorn Station included structural repairs, reroofing, external restoration and specialist conservation of original metalwork, joinery and the historic foghorn. Works to the Cholera Isolation Hospital focused on structural stabilisation, masonry repairs, crack stitching and the installation of new lime wall cappings to reduce further deterioration and improve weather protection. The project successfully safeguarded two rare and historically important structures, securing their long-term preservation for future generations.

KEY SERVICES DELIVERED

  • Architectural and QS
  • Programme & Risk Control
  • Cost Planning & VE
  • Tendering and Procurement
  • CA & Reporting
  • Detail Design
  • Monitoring of Planning Conditions

CHALLENGES & SOLUTIONS

The project presented unique challenges due to its marine oriented heritage design, environmentally sensitive SSSI location, and the logistical constraints associated with island access and nautical transport. These were addressed through a thorough Construction Environmental Management Plan (CEMP), robust planning of material deliveries and construction sequencing around tidal and weather conditions, and the use of sympathetic design solutions that minimised ecological impact while responding appropriately to the coastal and conservation setting.

PROJECT TEAM

ARCHITECT

CMS Architects Ltd

QUANTITY SURVERYORS

CMS PM&S Ltd

PROJECT MANAGER

WSP

CDM PRINCIPAL DESIGNER

WSP

PRINCIPLE CONTRACTOR 

KNOX & WELLS

STRUCTURAL ENGINEER

WSP