Cwrt Andrew Buchan Sheltered Housing Complex, Rhymney

Project overview

Cwrt Andrew Bychan is a three-storey retirement housing development owned by Wales & West Housing. As part of the Welsh Government’s Arbed energy efficiency programme, the building underwent a façade retrofit to improve fire safety, thermal performance and weather resistance while enhancing the external appearance.

The project was delivered with residents in occupation, requiring careful sequencing and a solution that balanced performance, compliance and minimal disruption.

The challenge

The key requirements for the project included:

• Improving thermal performance to meet modern energy efficiency standards
• Specifying a fire-safe façade solution suitable for multi-storey residential use
• Introducing visual interest without compromising durability or compliance
• Achieving consistent detailing around openings, projections and roof junctions
• Maintaining a high standard of workmanship in an occupied building

The client also sought a façade finish that combined a clean, contemporary appearance with textured detailing in feature areas.

The solution

A Wetherby masonry stone wool external wall insulation system was specified for its non-combustible insulation, thermal performance and design flexibility. The system incorporated A1-rated ROCKWOOL stone wool insulation boards and was finished using a combination of silicone render and acrylic brick slip finishes.

The primary finish was Wetherby Silicone 4S Render, selected for its rapid curing properties, high water repellence and resistance to variable weather conditions. Acrylic brick slips were introduced as a contrasting feature, providing the appearance of traditional masonry in a lightweight, flexible format.

The complete system achieved an A2-s1, d0 fire classification in accordance with BS EN 13501-1, making it suitable for buildings of any height.

Installation

The system was installed by SMK Building and Maintenance Ltd, a Wetherby-recognised contractor. Installation followed Wetherby’s approved detailing guidance, including:

• Interlocking insulation boards at all junctions
• L-shaped insulation boards at opening corners to minimise cracking risk
• Insulated plinth detailing at damp proof course level
• Fully detailed pitched and flat roof junctions to prevent water ingress

Wetherby provided ongoing technical site support throughout the installation to ensure compliance with system requirements and detailing standards.

Finishes and detailing

In addition to the primary render and brick slip finishes, feature areas such as porches and window surrounds were enhanced using a quartz mosaic render. This bespoke finish introduced additional texture and visual interest while remaining fully compatible with the overall façade system.

The combination of finishes allowed the building to achieve a refreshed, contemporary appearance without losing its original character.

The result

The retrofit delivered a significant improvement in thermal performance, with the external wall U-value reduced from approximately 1.27 W/(m²K) to 0.24 W/(m²K).

The completed façade provides enhanced fire safety, improved weather resistance and long-term durability, delivering a safer, warmer and more energy-efficient environment for residents.

Key facts

• System: Masonry stone wool external wall insulation
• Substrate: Masonry
• Insulation: 120mm non-combustible stone wool
• Finish: Silicone render, acrylic brick slips and quartz mosaic render
• Fire performance: A2-s1, d0
• U-value improvement: From ~1.27 to 0.24 W/(m²K)