Building study: Greenwich Design District

新格林威治设计区(Greenwich Design District)的成功之处就在于此，想要一个小工作室空间的创意人士必须排队等候。位于格林威治半岛的开发商Knight Dragon于2017年宣布，他们委托了8个小型建筑师为艺术家设计一个靠近O2和北格林威治地铁站的新区域。在一些人看来，这是一种玩世不恭的策略，目的是通过营造一种充满创意的氛围，来提高该地区对潜在买家的吸引力。如今，该地区已经完工，而且确实热闹非凡。这表明，只要有合适的空间和便宜的租金，这个想法是可行的。

Unlike the high-rise housing blocks surrounding the design district, this consists of buildings no more than four storeys high packed closely together to give the district an intimate feel. The blocks are mostly muted in appearance, being finished in materials including brick, concrete, aluminium and stainless steel. Two buildings stand out in this largely monochrome landscape, one clad in an orangey-brown Corten weathering steel and the other a vivid green which shifts to a bluer shade depending on how the light is falling. These two buildings also happen to be the only ones constructed from timber.

Designed by Mole Architects, the timber buildings were carefully modelled and designed to minimise embodied carbon and ensure that they would not overheat, a potential problem with lightweight construction and increasing summer temperatures. Now fully occupied, the realities of the different demands of a diverse community mean one of the buildings has been radically altered due to the specific requirements of the tenants. How flexible are these buildings and how are they performing 10 months after the design district formally opened?

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According to Meredith Bowles, principal of Mole Architects, the brief was straightforward. “The brief here was inexpensive space to let to creative industries,” he says. The brief included a floor-to-wall ratio that could not be exceeded – this was to keep down costs, which were set at a maximum of £3,000/m².

Bowles adds that there was an assumption that each floor would feature one big space. “We thought about Victorian warehouse spaces, which are perfect as they can take being banged around, have big windows with plenty of light and heavy structures which keeps them cool.”

业主故意让建筑师们彼此分开，他们的想法是，他们每个人都将产生一个独特的设计响应，由总体规划维系在一起。对于许多建筑师来说，在一个几乎没有背景线索的区域内想出一个有意义的设计叙事是一个挑战。鲍尔斯转而研究了该遗址的历史，在引入北海天然气之前，它是东格林威治煤气厂的所在地。

Research turned up a Second World War era photograph of two scientists who were working at the fuel research station on the site which was trying to find alternative fuels for navy ships. One scientist wore a black lab coat, the other a white one, and they were holding two very different, and strange devices which provided a narrative for the two very different looking buildings.

The Corten-clad building, which is known as the Ziggurat or C2 to give it the formal name, was inspired by the now dismantled gasholders on the site. The rusted surface of the Corten references the corroded frame of the former gasholder, and the building steps in towards the top like the telescopic holders that rise and fall depending on how much gas is being stored.

绿蓝色建筑的颜色，被称为菱形或D2，来自于气体火焰的颜色，窗户旁边的玻璃鳍增强了这种感觉，玻璃鳍具有二色薄膜，根据光线的变化从黄色到橙色的颜色变化。

Bowles说，很容易说服客户和承包商采用全木材建筑，因为Knight Dragon已经任命了一个经验丰富的顾问团队，包括Skelly & Couch for M&E和Whitby Wood作为结构工程师。Ardmore是负责建造新设计区的所有建筑的承包商。

This was a time when fears about the flammability of timber had not taken root as the buildings were designed before the combustible cladding ban. Building in timber was more expensive than concrete or steel, but this was offset by savings on the foundations as these could be less substantial.

The big gain is embodied carbon reduction. Not accounting for carbon sequestration, the Ziggurat has a foundations and frame embodied carbon content of 202kg/CO2m², a 41% saving over a traditional reinforced concrete frame. The Rhomboid demonstrates slightly higher savings as the embodied carbon is 271kg/CO2m², a 48% saving over the traditional equivalent. Both buildings have a calculated space heating demand of 52 kWh/m²yr, nearly 47% better than that required by 2013 Part L.

The Ziggurat has a glulam frame to enable the large spans on each of the building’s three floor levels. Cross-laminated timber (CLT) is used for the floor slabs and structural insulated panels (SIPs) for the exterior walls.

Bowles explains that, as the building steps progressively inwards at each level, the beams need to cantilever out on the lower levels as the columns are set back from the edge. SIP panels are lighter than CLT, reducing the loads on the cantilevers with the added benefit that these are installed in one operation rather than needing to install the insulation separately had CLT been used. The Rhomboid features vertical external walls, so features a CLT structure with glulam columns and beams at the centre of the building to support the large spans.

Ensuring that the building remained low carbon in operation during its life was important to Bowles, and to give it that cool, airy Victorian warehouse feel. Skelly and Couch modelled the building using CIBSE’s TM52 methodology and established that the building would become uncomfortably hot on very hot days when the building was fully occupied.

模型还显示，在外墙内部包覆相变材料——这些材料从液体变为固体，然后再次释放或吸收潜热——安装外部百叶窗将温度降低到更可接受的水平。

As the building would meet building regulations and BREEAM credit requirements without these measures, the client had to be persuaded that the additional investment was worthwhile. The overheating scenarios were presented to the client. “Fortunately, the contractor was in the room and told the story of a complex retrofit of an air-conditioning system,” says Bowles. “We said, ‘you’re going to get complaints because it will be uncomfortable’. Fortunately, they went for it.”

相变材料被整合到一个看起来像标准石膏板的材料中。鲍尔斯说，这种名为Thermacool的石膏板和传统的石膏板一样容易安装。通风通过带有热回收系统的机械通风提供，以节约能源，空气通过地板静压室提供。该建筑的气密性等级为3m3/m2 @50pa，这再次有助于节约能源。

金字形神塔的顶层是一个维多利亚式仓库风格的工作室。它的特色是锯齿形的屋顶，带有裸露的木椽、胶合板和朝北的灯。

It is being leased by a dance company called Clod Ensemble as a rehearsal space and, on the day that Building visited, the sun was shining and the space was flooded with light. The windows were open, and the space was pleasantly cool although it was 20ºC outside.

Roxanne Peak-Payne, Clod’s executive producer, says a range of people have used the space in multiple ways in different weather conditions and all are delighted with it. “The feedback from everybody who has come into the space – there is a kind of ‘wow’ moment every time someone steps in; it has a very big impression,” she says.

“对我们来说，使用天然材料和美学的高质量设计对于在办公室和排练室创造一个积极的工作环境非常重要。”

Peak-Payne says the top-floor space is pleasantly cool, even recently when temperatures exceeded 30ºC. “It has been very hot but the skylights open, and also when you open the long windows fully there is a natural draught created and it becomes cool very quickly, which is great.”

Downstairs, on the first floor, the cross-ventilation strategy has been compromised by the changes made to the building to suit Clod Ensemble. It is using this space for offices and a recording studio plus another tenant has taken a small space on one side of the floor.

This meant that the space has been subdivided with partition walls and the difference in temperature is noticeable although not unpleasant. This could be due to the blinds being left up despite the sun shining in.

Peak-Payne says the main office, which has windows on two walls, is fine but that a smaller room, which has windows on one side only, does get warmer but is still usable. She adds that the blinds have been used to reduce the sun’s intensity in the late afternoon and also in the upstairs rehearsal space in anticipation of hot weather.

并不是所有的工作人员都知道百叶窗的目的。负责Clod通讯的苏珊娜·赫斯特说，人们喜欢把百叶窗拉上，这样他们就可以欣赏风景。当鲍尔斯解释说，百叶窗的存在是为了遮挡阳光时，她表示惊讶。匹克-佩恩解释说，员工已经逐渐搬进了这栋大楼，所以一些员工可能不知道如何管理这个空间来保持凉爽。

The rows of windows on the south-facing elevation are arranged in groups of three with a blind for each group. Each blind is operated by a manual winder. Unfortunately, the location of one of the partition walls has separated the winder from the blind it is operating, with the winder in one room and the windows next door. Less than ideal.

Wouldn’t a building management system (BMS) automatically controlling the blinds solve these issues? Bowles says not: “A BMS has to be programmed and managed. There is the issue of user control and cost.”

Another issue is noise transmission. A dance troupe were practising on the top floor during Building’s visit. The volume was cranked up on the sound system and very noticeable in the offices below.

这种声音可能是通过每层楼打开的窗户传播的，但当低音为主的音轨开始播放时，很明显声音是从220毫米厚的平板传来的。音响系统是为专业使用而设计的，声音非常大;实际上，唯一能够抵抗这种噪音水平的材料是混凝土，尽管交叉层压层板可以胜任抵抗日常办公室和家庭噪音的工作。

The space between the Ziggurat and B2, a building designed by 6a with a steeply angled facade, is occupied by a giant transparent caterpillar-shaped construction. Designed by SelgasCano, which was responsible for the 2015 Serpentine pavilion, it houses food stalls.

This food had to be cooked somewhere, with the ground floor of the adjacent Ziggurat an obvious choice. This presented Bowles with a challenge as a space designed as an artist’s studio had to be made to work as a commercial kitchen.

“There were two issues. Firstly, would the space be high enough to fit in the ventilation system? And we were concerned about the impact of condensation and potentially fire on the exposed timber,” he says.

The ventilation system is bespoke and is effectively a giant cooker hood that extends along the length of the cooking areas. The glulam beams are 450mm deep and the ventilation system extends approximately 800mm below that. The floor has been raised to accommodate additional drainage. Despite losing some 1,500mm of headroom, there was still just enough room, a benefit of emulating high-ceilinged Victorian warehouses.

It has been very hot but the skylights open, and also when you open the long window fully there is a natural draught and it becomes cool

Roxanne Peak-Payne, executive producer, Clod

The ventilation system features powerful extraction fans which suck out the moisture generated by boiling liquids in saucepans. It is also fitted with a fire suppression system to tackle any pan fires. A fire-retardant coating has been applied to the exposed timber, too. “We were satisfied we weren’t doing anything foolish,” Bowles says.

One room on the first floor of Ziggurat is being set up as a recording studio by Clod Ensemble. The vibration generated by the ventilation system was transmitting through the slab into the studio. The problem was solved by swapping the ventilation system hangers for ones capable of damping out the vibrations. “If we had known that at the outset, it would have been easier to sort out,” observes Bowles. The studio is due to be fitted out by a professional sound studio specialist to take care of other noise.

菱形已被证明比金字形神更具挑战性，因为它被用于更传统的艺术目的。顶楼的特点是更传统的平拱，有大而平的开放部分屋顶。

It is being used by the Photography Foundation, which creates pathways for disadvantaged young adults into photography careers. Its sister company, Storytellers London, a photography agency, is on the floor below and there is a colour forecasting agency on this floor, too. The building also houses a company making bikepacking bags and another making bespoke trainers from recycled shoes.

The design district is over 90% full, with most of the available space in building D4 for a single let tenant who wants 10,000ft2 space over four floors.

The compromises engendered by some significant, unanticipated changes to the Ziggurat are centred on ventilation and to some extent user education issues rather than those imposed by the building structure. Which demonstrates that the embodied carbon benefits of timber construction do not come at the price of decreased flexibility.