David Hills, Michael Breen and Anne Wynne discuss how the practice’s approach to materiality is informed by contextuality, environmental concerns, and the accumulated knowledge of previous projects.
Anne Wynne, David Hills, and Michael Breen pictured in DSDHA’s meeting/crit space with a selection of products from the materials library.
Established by Deborah Saunt and David Hills, DSDHA is an internationally acclaimed architecture, urban design and research studio based in south London. Over the last 24 years, the practice has made a name for itself by producing high-quality, typologically diverse buildings that have garnered 19 RIBA Awards, as well as two nominations for the European Union Prize for Contemporary Architecture, and a Stirling Prize nomination.
Evocative projects, such as the National Youth Theatre pavilion in Islington, South Molton Street in Mayfair, Alex Monroe’s jewellery studio in Bermondsey, and Parkside Pavilion in Potters Fields Park, bring to mind materially rich and beautifully detailed façades made of glazed brick, profiled and glazed terracotta, handcrafted zinc, and charred timber respectively. Founding director David Hills, associate architect Michael Breen, and senior architect Anne Wynne explain how the work is informed not just by context and site history but by environmental issues, hands-on research, and the practice’s own back catalogue of works.
How is the materials library organised?
Michael Breen It’s organised by project rather than material type. Each scheme has its own labelled wooden crate containing all the material samples that pertain to it. We display some of the more interesting samples relating to current projects around the studio, so staff members can see what is being specified across the practice. David Hills Behind the workstations there are a series of shelves which house materials relating to ‘live’ projects. They are built up over the lifetime of the project, and in some cases tested outside in the yard, before being filtered down into the definitive final specification. Following completion of the building, the samples are archived as a long-term reference source for future works.
Faience cladding panel from NBK. “This is a bespoke faience façade panel developed for The Mansion on Marylebone Lane. The warm, pinkish red colour, which subtly changes depending on the time of day and viewing position, draws its inspiration from nearby Wigmore Hall and was developed with a specialist company in Germany over a two year period. A paler tone was used on the panels at the rear of the building in reference to white-glazed bricks commonly used on Victorian courtyards.”
Is anyone in charge of managing this process?
Michael Breen I’m responsible for the overall curation of the library, but I try to encourage the project architects to responsibly manage the resource. We don’t want the library to be too strict or rigid, but at the same time we want to avoid disorder!
So much of the library contains previously specified and project-proven materials rather than non-specific, generic products?
David Hills Yes, but the material input for a new building isn’t based on, ‘oh we’ve used this product before, let’s use it again’. The project-based archive serves as starting-off point for further development and investigation, following what is primarily a contextual response to the site and brief.
Glazed brick from St. Joris. “These beautiful bricks were specified for the National Youth Theatre pavilion on Holloway Road. They are not only suitable for tough urban environments but also evoke local historic buildings, including pubs and tube stations. We particularly like the higher intensity of colour along the edges of the brick, which is reminiscent of faience.”
At what point would you say that materials become a focus on your projects?
Michael Breen Delivering social value is one of our primary objectives with material selection following on from this. Saying that, materials are always on our mind, and their specification often arises from in depth studies into the project’s site history and/or surrounding context.
A good example is The Mansion at Marylebone Lane, a seven-storey residential scheme in London’s West End. We did a huge amount of material research in order to complement the area’s rich tonality of terracotta buildings. This involved bringing of samples to site gradually refining the glaze finish to see what would work within the local context.
On the Hickman, a large, adaptive reuse scheme in London’s Whitechapel, we subtly referenced the building’s historic former occupier: saw and tool maker Buck & Hickman in the form of metal grilles, balustrades and saw-tooth profiled screens, used throughout the interior.
David Hills Another good example is the National Youth Theatre pavilion on Holloway Road in north London. Internally, it was all about natural materials and the predominant use of timber, whereas outside, the focus was on highlighting the civic nature of the building, expressed through beautiful, green-glazed bricks.
Anne Wynne The glazed bricks, which are made in Holland by St. Joris and supplied by Ibstock in the UK, evoke the quality of the surrounding public buildings, such as tube stations and pubs, while also complementing the tough urban environment of the Holloway Road.
David Hills We wanted to make an appropriate public frontage for an amazing organisation that hitherto had very little presence on the street. The local red glazed-brick tube stations informed the building’s structure and form. A green glaze was eventually chosen in reference to the aquamarine/green faience panels on a local pub, itself an important community meeting space. The colour is also a reference to the backstage green rooms of performance venues.
Terrazzo floor tiles from In Opera Group. “We used bespoke terrazzo floor tiles for the Exchange Square public realm project in Broadgate. In contrast to the textured, non-slip surface, the perimeter of each tile features a thin, flush, polished bead. This ensures refined crisp edges when the tiles are laid next to each other, rather than multiple‘ rough’ junctions.”
What role does sustainability play in your material choices?
Michael Breen The practice ethos is ‘the best, for the most, for the least’; so it’s about providing the best quality experience for the least environmental impact. Like many practices, we are trying to better educate ourselves and improve our performance from project to project.
David Hills We try to reuse materials where appropriate. Inspiration for our recent competition-winning interpretation centre and gallery adaptation for the Henry Moore Foundation in Hertfordshire came from the sculptor’s material frugality and the way he would re-use existing buildings by literally bringing them to his estate from elsewhere.
One of our early projects, Parkside Pavilion in Potters Field Park, London, explored how to avoid treating timber structures with preservatives. We ended up charring the surface of the horizontally stacked timber walls; only finding out later that this is actually an ancient technique that is still commonly used in Japan. We experimented with char times using blow torches in the office yard, before the contractor set up a purpose-made rig. I believe that this was the first time that the process was used in the UK.
How do you go about finding usable recycled materials for your projects?
Michael Breen It’s getting easier. I went to the Surface Design Show earlier in the year and found a huge number of innovative products made from recycled materials. It’s heartening to see so many companies out there rapidly developing quality products that use waste plastics and other discarded materials.
Uncoated Corten steel cladding section from M&M Architectural. “We wanted to create a veiled moiré-like façade for the Alex Monroe Workshop in London and decided to employ horizontal Corten steel ‘blades ’to achieve this effect. The blades form part of larger rainscreen-style panels, which include simplified classical reliefs evoking those found on surrounding Victorian buildings.”
Do you find that clients are more knowledgeable and enlightened about environmental issues today?
David Hills It forms the starting point for most briefs. With the Henry Moore Foundation, for example, the target is to approach net zero carbon. On office projects, the client’s first question is invariably, ‘what does net carbon mean to you for an office building?’ This extends all the way from material selection to operation in use.
Anne Wynne This ties back to the idea of reducing material content. For instance, we were able to significantly reduce the amount of concrete in the floor slabs of a commercial project in Piccadilly by simply adding a single column to the structural grid. While this may detract slightly from the open-plan nature of the space, the environmental benefits are well worth it. Likewise, deciding to eschew suspended ceilings in place of exposed soffits and utilising self-finished rather than painted internal elements can make a real difference over the lifetime of a building.l
Materials that last a long time, age well and don’t require any specialist maintenance appeal to us for their ability to minimise resource depletion and future labour costs.
Corten Steel seating component from Millimetre. “Bespoke designed for Exchange Square park in Broadgate ,this full-scale mock-up forms part of an external curved seat. The element, which is inspired by the train tracks of nearby Liverpool Street Station forms a visual edge to the landscape before transforming into the parapet of the park pavilion. We decided to use acid-washed and blackened galvanised steel in the final specification to eliminate the chance of rust from the Corten staining the surrounding white terrazzo floor tiles.
Does material research and innovation occur in house or do you develop relationships with specialist suppliers and manufacturers?
Michael Breen Understandably, many clients are risk adverse when it comes to doing something that is new and untried, so we work closely with experts to achieve the right result. Alex Monroe’s jewellery studio in Bermondsey is a good example. We worked closely with specialists to ensure that the bespoke, handmade Corten façade would be resistant to surface staining and water drips over its lifetime.
David Hills We did a lot of material experimentation with specialist manufacturers on a series of projects that preceded – but were linked to – our Exchange Square public park in the City of London. One of the briefs was for a series of large, reconfigurable, multi-use structures, which we decided to design in timber utilising specialist stage-building technology. The client played a huge role in facilitating this, as many in their position would have probably wanted a standardised product with interchangeable parts in case of future damage.
Anne Wynne Exchange Square also enabled us to experiment with landscape elements, including bespoke 3D-engineered terrazzo floor mixes, which were tested for aesthetic performance, water resistance and weathering in our yard. We’re fortunate that the office is next door to Szerelmey, so they did the full-size mocks in their yard, which is much bigger than ours!
Our original intention was to recycle existing red granite paving, by grinding it down and remaking it into terrazzo, but this proved unfeasible in terms of carbon cost. Since this project, there has been a gradual increase in awareness of the opportunity for reusing and sharing unwanted site materials between other London-based building projects. We think that material exchanges will be key to future recycling within the construction industry.
End grain European oak flooring from Naturally Wood Floors. “This is an attractive, natural, self-finished and hardwearing flooring product that very much fits the ethos of the practice. We are looking to use it on our Arts and Crafts building refurbishment project on Blossom Street.”
Coming back to new materials and construction methods, what specifically interests the practice and why?
David Hills It’s about finding the right material for the project. The community building we designed for Greenwich Peninsula, for example, took its inspiration from the gasometers that had previously occupied the site – rather than a particular preference for steel and glass structures.
The material we’ve reused the most is terracotta. Our South Molton Street project in London demonstrated how this traditional material can be used in a contemporary way. We used terracotta subsequently – albeit in a slightly different way and glazed in the manner of faience –on Marylebone Lane. It’s masonry based, it’s really robust, and has a visual character that changes depending on the time of day. We tend to favour a pared-back material palette, and terracotta allows us to articulate façades with shadow and light, rather than introducing additional elements or colours. There is tremendous tonal range when it comes to glazes, reflecting the wonderful patina that often develops over time.
Is there a material that you would like to use in the future but haven’t been able to yet?
Anne Wynne We’ve been exploring the potential of using structural timber piles with Steve Webb of Webb Yates. Our office is close to Vauxhall Bridge and there are timber piles sunk into the riverbed that have lasted for hundreds of years. The opportunity to use really primitive forms of construction is exciting. We’re also talking to Webb Yates about using structural stone to construct an external lift. It’s about using traditional materials in new ways.
Corrugated and perforated metal sheet from Glassolutions.“This metal sheet formed part of the façade of the Greenwich Peninsula community building. It provides the required industrial aesthetic while also modulating daylighting, privacy, and views into and out of the building.
What happens to samples that are not archived when projects come to an end?
Michael Breen The most interesting materials are retained and/or put on display, but space is limited so we have to be selective. Some suppliers have adopted new methods for distributing samples. James Mossman, for example, employs a mobile brick library, which comes to the practice.
Do you find that manufacturers are happy for you to send product samples back?
Michael Breen The focus seems to be on getting their name and products into practices rather than having a strategy for dealing with this particular aspect of recycling and waste.
Charred English oak from Shou-Sugi-Ban. “We experimented with charred timber on Parkside Pavilion, and are planning to use it again on a new-build office that forms part of the Blossom Street development. The materials palette also includes dark bricks and glazed lavastone tiles in reference to a tinder box company that once occupied the site.”
Is it a case of ‘narrowing down’ a wide array of products online first, before cherry picking a few physical samples for evaluation in the studio?
David Hills That’s an interesting question. Bricks, for instance, look completely different online than they do in real life, so you can only ‘edit’ the online selection to a certain extent. The physical sample is always going to be important because we don’t look at materials in isolation; we want to see them next to the other elements that make up the palette. And of course, clients want to see this too.
So how do you manage waste in the library?
Anne Wynne We have an annual audit of the products that do not make it into the project archive boxes. The yard gets full of largescale external materials and sometimes people will take these for use on their own building projects. Some get recycled into studio maquettes or taken home and converted into household items, such as wooden chopping blocks.
David Hills Cataloguing is incredibly important. There’s no point in keeping something if you don’t know what and where it is!
