1 New Park Square, Edinburgh

1 New Park Square is the first landmark project for the wider vision of a low-carbon community of working, living and leisure at Edinburgh Park by developer, Parabola. The building echoes this philosophy through robust long-lasting materials, low energy in-use, supported by the use of an exposed concrete frame.

Judges' Comments:

The visual impact of the concrete throughout the building is simply stunning. Walking into the main reception to see the exposed concrete being complemented by various forms of art and lighting is refreshing to see. The GGBS partial replacement concrete being used for the walls with the darker CEM I concrete on the soffits creates a contrast, which works well throughout. Great attention was taken with the tie holes to ensure uniformity in design but also ensure the visual impact is not affected in any way.

The wall and soffit panel sizes are noticeably consistent throughout, adding to the visual impact of the exposed concrete, which has been improved through using bespoke forms. The concrete finish together with the consistent panel sizes enhances the impact of the exposed concrete throughout. Any blemishes actually add to the authenticity of the build. This building should be promoted and celebrated as a best use of concrete within construction.

DAMAC Tower, Nine Elms, London

DAMAC Tower is sometimes referred to as the 'Jenga' tower, due to its unique building silhouette in which the façades of the building's massing push and pull in and outwards. By careful planning of the structural grid to match with the linear façade, up to 4.5m cantilevers were achieved with no impact on the floor-to-floor heights.

Judges' Comments:

The use of high-strength concrete was nothing new but the only material capable to achieve the vision of the designers. The hanging concrete soffit that contained the spa pool had to be kept within the confines of the south block.

The cantilevered sections at height were able to exploit the space above in proximity to the live rail track. The bridge not only spans the buildings but also at the front is cantilevered forward. Large steel tendons proprietary and traditional were embedded into the concrete frame to receive the steel and simplify interfaces.

The complexity behind this build is easily appreciated. The cost per square metre for project development was quoted as being approximately 80% of other developments across at the main Nine Elms project site.

The engineering involved is complex and worthy of a commendation.

Newlyn Coastal Research & Development, Penzance

A field-based pilot project to evaluate the performance of various ecologically enhanced armour units in an intertidal high-energy wave environment. The ecological armour units are designed to encourage the settlement of marine organisms, providing a carbon sink as well as withstanding high-energy wave conditions and providing shoreline stabilisation.

Judges' Comments:

Concrete serves an excellent functional purpose here, as the blocks are designed especially for prevention of coastal erosion and protection against flood, at the same time as fostering the growth of marine organisms.

As the blocks have already attracted substantial algae growth their appearance is in keeping with the rest of the stone breakwater and this also allows them to appear more 'natural' in keeping with the environment. The units do appear to have been very successful in developing the formation of marine life.

The use of concrete is well established in marine and coastal locations but this project, while small scale, is part of a wider Environment Agency scheme to determine the best shape profiles to protect coastal flood and erosion at the same time as supporting the settlement of marine organisms. It is therefore innovative, not relying on established products or schemes and could have wider opportunities for concrete development in this situation.

Osiers Road, Wandsworth

The Osiers Road façade is a showcase in the richness and variety of finish that can be achieved with architectural precast concrete. This multi-finish unitised system, both uniquely stunning and cost-effective, creates a striking aesthetic that is sympathetic to the local history and was achieved through careful modelling, bespoke mouldage, multi-stage casting and innovative fixings.

Judges' Comments:

Careful accurate modelling was required to achieve the quality finish on this project. Pigmented concrete was used. The light concrete gave fossilised appearance whereas the black pigmented concrete was of matt finish. Bespoke moulds were developed for the weave pattern panels using rubber, which helped to hide the joints. It must be stated that the corner sections of the weave panels were remarkable in the finish, giving the effect of wrapping around the structure's edges.

Acid etch on all weave precast was used to give a completely unformed finish. The remit was to keep the design, form and layouts as simple as possible, which was satisfied. No sign of weathering or stains, maybe due to the pigment included in the concrete. Even with the fall across the site the bottom section lined up immaculately with surrounding pavements. To get this detailed so well is a testament to the planning involved.

The Salvation Army New THQ, Denmark Hill, London

This is a new flagship office; a five-storey building, partially embedded into the sloping site and with a large central atrium. Exposed concrete ribbed slabs and exemplar plain finish walls provide a sustainable, economic, flexible and stunningly attractive space.

Judges' Comments:

This is a five-floor building embedded into a sloping site with a large central atrium. Constructed with exposed concrete ribbed soffits and plain finish to core & walls, the design accommodates space requirements from the informal open office to break-out areas and hierarchic rooms (based on army culture). Some Precast elements complement the in-situ concrete.

The client brief was for a plain finish concrete rather than it being value engineered. It would make a good reference for benchmarking.

The ribbed slabs have been designed with band beams around column heads. Ribs reduce material usage compared with a flat slab and allowed the foundations to be reduced in size due to lower self-weight. The ribbed slab also improves head height, as services are incorporated in the ribs. A raised floor above the slab accommodates service distribution.

A simple clean and practical finish was the sole requirement of the concrete elements.

Kathy Calverley, Managing Director, The Concrete Society
Ian Evans, Principal Engineer, The Concrete Society
Ian Heritage, Senior Advisory Engineer, The Concrete Society
Richard Barnes, Advisory Engineer, The Concrete Society
James Niland, Advisory Engineer, The Concrete Society
Deiniol Willams, Past President, Fosroc
Paul Browne, Past President, Mapei

Supporting sponsors

The Concrete Repair Association

Award Winner: Concrete Repairs Limited, M6 River Dane Bridge (Area 10) Phases 1 & 2

The main shaft building is a 50-year-old cast-in-situ concrete structure, with an external elevation extending 45m above ground. Its coastal location and sulfides from the mine contributed to reinforcement corrosion, compounded by high internal levels of humidity. As principal contractor, CRL's skill and expertise in finding solutions to the complex structural issues that arose enabled it to manage and carry out the works throughout the pandemic. The judges commented, "We were impressed by the range of skills and concrete repair disciplines involved, with significant structural repairs. What really made CRL stand out was the level of detail and clarity regarding environmental impact and sustainability."