Architect: DaeWha Kang Design
Façade Engineer / Consultant: ARUP
Contractor: Octatube
Client: OWO
The Old War Office (OWO) Pavilion aimed to provide a new hospitality space that revitalizes the Courtyard of the Old War Office, now converted into a hotel and residences. The project serves as an exemplary case study of a contemporary addition within a Grade II listed context.
The courtyard's historic cobbles were re-laid in a radial pattern to accommodate the Pavilion, a sculptural water feature. Light landscaping and outdoor seating create a respectful, vibrant atmosphere that bridges the site's history with the new design.
The sensitive heritage context necessitated a high degree of integration between structural, façade and mechanical systems. The envelope comprises three key façade types: glazed perimeter walls, a rainscreen roof system, and a glass skylight.
Image credits: DaeWha Kang Design (DKD)
Glazed perimeter openable walls
Designed to be slender, lightweight and highly efficient, the glazed façade system avoids compression transfer from the roof into the façade posts, which however act as tensile outriggers to limit the pavilion's sway and minimize tolerance requirements at the roof-glazed wall interface.
A modified slimline Jansen steel system supports large openable glass panes, offering a light, transparent design that seamlessly integrates with the courtyard for an immersive indoor-outdoor experience.
Concealed within the mullions are integrated roof drainage downpipes, demonstrating design teams’ meticulous attention to detail.
Roof
The roof features a traditional warm construction with an EPDM membrane, overlaid with architecturally mirror-polished stainless steel rainscreen panels. The insulation in this opaque part of the building ensures occupant comfort in all seasons.
A collaborative process with the lighting team refined the 3D panel shapes to prevent disruptive reflections on the courtyard façade.
During fabrication, rigorous testing and quality control procedures ensured that all elements met the architectural aspirations, while responding to limitations of fabrication and material properties.
Research into processing sequences minimized waste and optimized panel thickness. Curved panels added stiffness but had to remain within allowable elongation limits during pressing of the pre-polished panels.
Efficiency was further improved by reusing a single mould for panel forming across all panel shape variations. The mould was gradually deepened to create more curved panels.
Skylight
A fully prefabricated, bespoke modular skylight completes the roof structure. As both a structural and decorative element, it was fully preassembled in a workshop to meet tight tolerances. The utilisation of Raico Therm+ system supports its expressive form.
Image credits: Octatube
Design for disassembly
The project’s core suitability principle is exemplified through its design for disassembly. From the outset, this approach influenced every aspect of the pavilion's design and detailing. By using only bolted connections and avoiding on-site welding or bonding, the pavilion can be entirely disassembled and reassembled elsewhere without needing to reproduce any elements. This extends the lifecycle of materials, reduces waste, and minimizes environmental impact.
Proprietary products were adapted to realise this project’s specific aspirations, delivering unique solutions without the need for additional system testing to demonstrate performance. Through collaboration and engineering expertise, the project achieved its goals and set a benchmark for reuse. By utilising high-quality, long-lasting materials the pavilion can be repositioned to a different place in timeless architecture.
Construction
Installing the pavilion’s façade and roof cladding to precise tolerances was another significant challenge. The pavilion, circular in shape, is visible from all angles and close distances, with its roof cladding arranged in a circular grid visible from rooms overlooking the courtyard. To meet exacting installation standards, a bespoke set of installation limits was defined. The contractor employed a template that was gradually moved and adjusted as the roof panels were installed from the centre outward.
Conclusion
The OWO Pavilion revitalizes a historic space, contributing significantly to architectural design and its context.
The project is a testament to a highly collaborative environment, excellence in design and fabrication and a unified drive to achieve the best possible outcome.
Image credits: DaeWha Kang Design (DKD)