C1, one of the first buildings to complete in the new Design District on Greenwich Peninsula, is a pared-back, super-flexible workspace – complete with rooftop basketball court, writes Jon Astbury
25 August 2021 By Jon Astbury. Photography Taran Wilkhu
Given that the entire concept behind Architecture 00’s C1 building – a metal mesh-wrapped stack of raw concrete floors at Greenwich’s new Design District – is one of incompleteness, it is strange, but perhaps appropriate, to visit it at a time when it is one of the few completed buildings among a cluster of scaffolding and emerging concrete frames.
‘For me, the most exciting time is when a big development is under construction, when it is all concrete frames,’ says Architecture 00 co-director Lynton Pepper. ‘It has a sense of potential – this could be this. As soon as you clad it, it becomes: this is that.’ It was a desire to capture that ‘building site potential’ that has seen C1 left in its state of arrested development. Rather than completely filling and cladding this raw stack of concrete floor plates, it has been left exposed, with three floors of offices efficiently squeezed inwards to create a series of large external decks. Atop the building, an open steel frame encloses a rooftop basketball court. The whole structure is wrapped in metal mesh, fixed to the edge of the floor plates with exposed, piercing-like brackets. It is wonderfully and visibly straightforward. Pepper describes it as a case of ‘what can we pare this building down to? A series of decks, with some insulated bits in it and mesh to stop people falling out of it – that’s pretty much it’.
C1 is one of what we might unofficially call the ‘gateway’ buildings for the Design District – four structures that occupy the outermost corners of each of its four clusters, denominated A (north-west), B (south-west), C (north-east) and D (south-east). Along with Barozzi Veiga Arquitectos’ A1 building, a shiny metal cuboid set to be occupied by Ravensbourne University, Architecture 00’s C1 building forms the northern face of the masterplan. This is by far the busiest edge, being the main pedestrian route to and from North Greenwich station (itself set for redevelopment), and the most exposed, albeit slightly blocked by Marks Barfield’s 2014 Gateway Pavilion.
More on this topicDesigning the Greenwich Peninsula’s Design District
This prominent position lends 00’s decision to aim for rawness – seen both at C1 and at its sister building, D1, on the site’s eastern edge – some added boldness. What Pepper describes as a risk of ‘façade wars’, given developer Knight Dragon’s ‘design blind’ brief, has certainly played out across the Design District’s four clusters, and not to its detriment. But, in eschewing a more traditionally clad envelope in favour of metal mesh, 00 has drawn on its own set of references, be it Frei Otto’s Aviary at London Zoo or, at a more mundane scale, the mesh that surrounds the nearby Greenwich Peninsula golf driving range.
Architecture 00’s approach cleverly solves some of the site’s challenges, while also introducing some of its own. The Design District comprises purposefully tight and comparatively low plots, thankfully refusing the Greenwich norm of Tesco Express and Wagamama-filled podiums supporting tall, bland towers. Giving over such a large amount of space to external decks – and having faith in tenants to activate them – was by no means a small decision, but one that 00 felt was crucial to its philosophy of creating buildings that ‘enable people to do stuff’.
In consideration of the small size of the site, the ratio of net to gross internal area was maximised by eliminating a central core that might eat up space in the offices themselves. This makes the workspaces incredibly simple and non-prescriptive, and it is given a more refined feel than the rest of the scheme by the gold-coloured aluminium frames that surround them. It is the building’s mesh wrapper that transforms these spaces, allowing the large sliding windows to be completely opened to the outside without the need for balustrades.
Stairs, lifts, toilets and plant have been pushed to the outside, meaning they require tenants to leave their offices to reach them. In part, this was to fulfil a desire in the brief for each block to have its own legible ‘front door’, rather than one entrance for all tenants. But it was also key to 00’s vision for external spaces that would be an active intermingling of the tenants and the public – spaces that would be not just an add-on but a key aspect of the everyday life of the building. In another ingenious move, the external stair on the building’s southern edge interlocks as it moves upwards, meeting the fire escape requirement for an external deck of this size without having to use up yet more space by adding another separate stair.
An insulated wall wraps the central facilities, finished in some places with polycarbonate, but beyond this there is only mesh between users and the elements, a condition that was created to enable the sort of messy workshop-style activities tenants might wish to undertake without requiring costly M&E facilities in the interiors.
‘We thought everyone would do an “internal” building; you’d work inside with nice windows and nice lights,’ says Pepper. ‘But what if users want to do something different? What happens if they want to set up a CNC factory in there?’
A vision for such open, flexible space rarely makes it into reality unscathed. Originally this external access and decking was to be fully public, but developer Knight Dragon required security doors to be installed, meaning the only fully public area is the first flight of stairs, which will no doubt be well used as seating, given its position facing SelgasCano’s nearby food court, or the canteen. Likewise, it is more probable that the offices’ computer-based tenants will use their external decks for smoking, lunch breaks and evening drinks, rather than, say, spray painting or wood cutting. But it is nonetheless a generous provision, made more so by the surprising feeling of freedom brought by the mesh’s elimination of the need for balustrades in these areas, save for a thin, waist-height piece of steel wire, which is primarily for psychological assurance.
The mesh gives rise to some strange moments and conditions. On the more public-facing north and eastern elevations without wide decks, a tiny gap between the windows and mesh can just about be squeezed through. This will likely not be of much use to tenants but is a great help for window cleaners, who can work on each level without a lift.
The rooftop basketball court was not originally in the brief, but proposed by 00 and funded by scaling back the amount of mesh wrapping the practice’s other building, D1, which features a more conventional glass ‘hat’ atop its raw concrete floor plates. Intended as a space for a range of sports activities as well as events such as outdoor cinemas, it will be bookable by tenants and the public alike. For confirmed tenant Concept Kicks, a trainer brand that was looking for a space with concrete floors high enough to have a basketball hoop, it is a set-up that feels as though it were meant to be.
The internal area was maximised by eliminating a central core that might eat up space in the offices
Surprisingly, this appears to be the only rooftop space provided in the Design District. It gives a unique view to the south-west of the District’s curious collection of buildings. Again, the mesh brings openness to this space, as well as adequate protection from falls.
Like many schemes in the Design District, C1 has a bone to pick with contemporary commercial developments, and rightly so. It attempts to address issues around the extreme lack of generosity found in and around office and work spaces, particularly when it comes to usable external space. As with the whole District, much depends on the tenants, who will to a large extent determine the success of C1’s provision, but the building itself sits at a wonderful and inviting meeting point of simplicity and strangeness that is full of potential.
Jon Astbury is assistant curator in architecture and design at the Barbican Centre
An important part of the brief for the building was to achieve a BREEAM Excellent rating, using natural ventilation and local MVHR units, as well as connecting to the district heating.
Our design approach was to maximise passive systems such as high thermal performance and an airtight envelope. We have provided large amounts of glazing for natural daylight, created solar shading via the walkway decks and stainless steel rope enclosure to minimise solar gain, and exposed as much thermal mass as possible internally to reduce the thermal peaks. Fully openable windows enable maximum natural ventilation and nighttime cooling as well as providing a smaller surface area of heat loss by primarily only insulating the net internal area. All these passive measures reduce the requirements for active systems and therefore reduce the whole-life carbon cost.
The design uses as few materials as possible and the number of bonded materials was reduced to aid future recycling. Self-finished materials were preferred, avoiding requirements for finishes and thereby reducing carbon emissions.
The concrete mix includes a high level of waste material to reduce embodied carbon. Concrete was chosen to provide high levels of thermal mass as well as a robust, long-lasting infrastructure that allows the ‘infill’ to be reconfigured over time. Though the slabs appear to continue from inside to outside, there is no thermal bridging, owing to the use of concealed thermal breaks. Lynton Pepper, director, Architecture 00
Thanks to its location at the northern entrance to Design District, beside the O2, C1 bears responsibility for creating the first impression, encapsulating what Design District is all about, and enticing people into the site.
Architecture 00 rose to the challenge by creating a building that emphasises light, air and openness. This is largely thanks to the publicly accessible concrete stairs on the exterior, which ascend the three floors of studio space to the rooftop. The choice to cover this with a mesh balustrade creates a transparent façade, offering visibility in both directions, which makes the building feel much more democratic and makes the most of views across the O2 and beyond.
This move also creates versatile terraces that can be used as breakout areas or outdoor workspaces, giving opportunities for tenant studios and workshops to engage with the public. C1's crowning glory, however, has to be the rooftop basketball court. With a commanding position and incredible panoramas, this head-turning space can be used for a range of sports and wellbeing activities, as well as outdoor events, and further underlines the animating idea that Design District is a creative community open to all. Helen Arvanitakis, director, Design District
This project was quite an ‘engineer’s playground’. C1 is an exciting structure, with interesting challenges and complex details wherever you look. It was refreshing working with architects keen to celebrate and expose the complex structure.
Large spans create impressive open-plan spaces internally, with floor plates that shift around at the different levels to create satisfying overhangs, achieved using large structural cantilevers and transfer elements.
A unique and interesting aspect of this building was helping the architects achieve the external circulation zones, walkways, stairs and lift cores, as well as the externally-hung concrete façade, which is wrapped in a steel tensile mesh. We designed a steel frame encased in concrete to support the three-storey concrete stairs, taking the weight of it down through one supporting steel column via a gigantic storey-deep truss.
We look forward to playing the architects at a game of basketball on the rooftop court, which is enclosed by a steel frame that restrains the mesh façade. Elliott Connolly, associate director, Whitby Wood
The building was designed to be a series of slabs that could be infilled to provide whatever enclosure was required at that time. It therefore makes use of very few materials, with concrete forming the main structure and walkways and only curtain walling and polycarbonate providing the infill.
To allow the decks to be used for many different functions, the building is wrapped in a net of stainless steel wire rope that also functions as balustrading and solar shading.
The structural slab is thermally broken at the head or base of the curtain walling, thereby creating a continuous insulation line through the entire envelope. The concrete slabs provide robust solar shading to the façade externally as well as thermal mass internally.
The seeming continuity of the slab from inside to outside reinforces the sense that the infill envelope can be adjusted and manipulated to suit future needs. The decks themselves are robust enough to provide a permissive environment that users will not be afraid to knock about nor feel precious about the finishes. Lynton Pepper, director, Architecture 00
Start on site February 2019 Completion June 2021 Gross internal floor area 925m² Net internal floor area 825m² Construction cost Undisclosed Architect Architecture 00 Client Knight Dragon Structural engineer Whitby Wood M&E consultant Skelly & Couch Quantity surveyor Artelia Principal designer Stace Main contractor Ardmore Approved building inspector Royal Borough of Greenwich CAD software used MicroStation
Annual CO2 emissions 10.54 kgCO2 /m2/yr Percentage of floor area with daylight factor >2% Awaiting results On-site energy generation District heating Heating and hot water load Unavailable Annual mains water consumption Awaiting results Airtightness at 50Pa 5.3 m3/hr/m 2 U-values Walls: 0.2 W/m²K; Floor: 0.2 W/m²K; Roof: 0.13 W/m²K; Windows: 1.37 W/m²K
Tags Architecture 00 Greenwich Design District Greenwich Peninsula Office
Love to know how much it’s going to cost tenants to ‘do stuff’ here.
Creatives are fleeing London due to greedy landlords and the type of regeneration which pushes out the very people who started the whole process will it just become a tech start up ghetto?
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