"It's hard to fall out of love with Mies's glass box"

Architects' obsession with glazed facades is coming to an end, says Arup facade specialist Mikkel Kragh. He tells Amanda Birch how the future will look very different.


You have said that this could be the decade of the facade engineer - what did you mean by that?


The building envelope represents 25% of construction costs. It is fundamental in terms of building performance, it is the image of the building and there is tremendous need for co-ordination and integration to avoid costly failures and shortcomings. The focus on value for money, combined with environmental performance as a driver, is putting new emphasis on the role of the facade engineer as an integrator.


What are the key issues facing facade design?


Architects need to be aware of two main issues: first, adapting existing buildings to deal with a changing climate; and, second, enhancing performance to mitigate climate change. With retrofit and new- build we need to consider performance not just in terms of energy consumption but also embodied carbon.


Are we going to see fewer commercial buildings with floor-to-ceiling glass?


I was part of a glass debate a few years ago and it was considered that the market was driving the floor-to-ceiling aesthetic. Letting agents claimed they couldn't attract tenants without large amounts of glass. We felt we should educate the market.


It's not necessary to feature fully glazed buildings - non-transparent facades can be just as exciting. However, we are not there yet. The market appears to expect transparent buildings. It's almost a default expectation and is not the right starting point. In the future we will see an increased emphasis on materiality - glass is a wonderful material but it could be used differently.


We are doing research into composite facades [glass fibre reinforced polymers] and we should be considering low carbon options and designs for disassembly and the reuse of materials.

[translucent fibre-reinforced polymers]

In our research into timber as a structural material in high-rise buildings, we predict that timber will be used as a low-carbon structural material that will be integrated with the cladding, and we will see a return to more traditional ways of construction.


Is energy-efficiency becoming more important than a facade's appearance?


It depends on who you are talking to. As someone once said:


"Good architecture must be sustainable but not all sustainable architecture is good architecture."


There are architects who go further than the building regulation requirements, but the typical scenario is an architect asking: "How much glass can we get?" This is obviously the wrong question as it's aiming for the lowest acceptable performance of the facade and this is really sad.


It is hard to fall out of love with Mies's glass box, but I predict that materials and materiality will drive a new trend after having indulged in so-called "transparency" for the last few decades.

[Ludwig Mies van der Rohe]

What buildings have you worked on with facades that we could learn from?


With Ropemaker Place [designed by Arup Associates] we designed a facade that fulfilled three scenarios: it complied with building regulations, it followed the client's brief, and the team wanted to design a sustainable building for a low-energy tenant - it was brilliant!

[Ropemaker Place _ Arup Associates. Photo (c) James Ward]

I also worked on the Danish Pavilion for the Shanghai Expo 2010 with Danish architect BIG. We proposed not having air-conditioning in the pavilion, which fundamentally changed everyone's expectations for a summer Expo in Shanghai. Instead we naturally ventilated the building.  The pavilion was made from a perforated steel envelope and featured large openings at ground and roof level. It was a beautifully integrated building and attracted 5.5 million visitors.

[Danish Pavilion, Expo 2010, Shanghai _ BIG Architects]

What new facade materials are you researching?


We've been working on composite materials [glass fibre reinforced polymers] and what these new materials can do in high performance facade systems. We are also looking at low-cost, transparent, building-integrated photovoltaics, which is the Holy Grail. We are focusing on bringing down the cost of PVs and we are at the early stages of developing this. The technology won't be on the market for another few years and we are yet to see if these PV coatings are aesthetically acceptable.

[translucent fibre-reinforced polymers _ The Integrated Building Envelope]

I'm also involved with companies such as Formtexx to create cost- effective free-form envelopes that enable architects to work more freely with form.


Has there been an improvement in collaboration between the disciplines of architecture, structures and services to achieve a well-integrated facade?


There is always room for improvement, but it has got better. Clients are more aware now and we can save them money and trouble if they possess a good business sense and want facades that not only comply with the regulations, but deliver over and above this level to provide high performance and low environmental impact.


Why do you believe the term facade engineering should be changed to building envelope engineering?


A lot of people associate facade engineering with hi-tech steel and glass but it is much more than that. Facade engineering also deals with, for example, roofs, conventional brickwork, stone and composites and is a very broad field. However, I fear the name won't change as people have invested a lot of time and energy putting facade engineering on the map.


Are the Part L building regulations relating to facade design stringent enough?


Personally, I think some curtain walling systems will struggle to comply with a strict interpretation of the regulations. Coming up with solutions and understanding the subtleties required is not that trivial anymore.
We will see new systems coming in and less transparent facades, but I do believe we can go further. The end game is that buildings should be energy efficient. How we get there is a political decision and a compromise between industry professionals and a need to reduce carbon emissions.


What is your favourite facade?


This is not an easy question as there are many modern examples, but I will mention an historical example instead, which is Gropius's Bauhaus in Dessau. It's an unbelievably modern and elegant building for its time especially when you take into account that it was built in 1925. 

[Walter Gropius]

The facade wouldn't perform to today's standards, so it has problems, but I would like to take inspiration from it for developing facade design that, as they say, does what it says on the tin - it's very simple, does the job and is outstanding.

[Bauhaus Dessau _ 1925 _ Walter Gropius]

[Building Design 21 April 2011 (c) 2011 CMP Information Ltd.]

Facade Engineering Insight

YouTube style interview recorded in connection with the Facade Design and Engineering conference in London, October 2010.

Design Science

"

The function of what I call design science is to solve problems by introducing into the environment new artifacts, the availability of which will induce their spontaneous employment by humans and thus, coincidentally, cause humans to abandon their previous problem-producing behaviors and devices. For example, when humans have a vital need to cross the roaring rapids of a river, as a design scientist I would design them a bridge, causing them, I am sure, to abandon spontaneously and forever the risking of their lives by trying to swim to the other shore.

"

[R. Buckminster Fuller, from Cosmography _Source: Buckminster Fuller Institute]

Engineering and Material Evidence (interview)

Your specialisms are; facade engineering, building physics, integrated design, facade technology and R&D, building performance simulation. What do you find so fascinating about the building skin?


I find the building envelope fascinating because of its obvious impact on architectural expression and the spaces we design. Successful design, engineering, and production of building envelopes require integration across disciplines. The building envelope has a – for me at least – unparalleled impact on the perceived qualities of architecture – in terms of both aesthetics and performance.


At the seminar you said: “there is definitely science in what we do”, This, I believe, is related to your understanding of Material Evidence! How is Material Evidence developed and evaluated in your praxis?


We would probably never use the term ‘Material Evidence’, but our Firm [Arup] is generally known for its creative and innovative approach to Design. As engineers – or designers – we are often trying out solutions beyond ‘the known’ and forced to work from first principles. One of my tasks is to spot research elements embedded in our engineering work – Research which would normally go undetected because the engineer sees it as a natural part of solving an engineering problem or challenge. Communication is instrumental to the creative approach and the testing of innovative ideas involves mathematical, physical, and virtual modelling.


In the Material Evidence seminar you talked about the idea of “total design” as a practise taking place between the disciplines. Could you elaborate on this idea and explain how this new interdisciplinary process creates a new platform for research in architecture?


Total Design takes on different meanings depending on context. I guess it’s shorthand for integration of disciplines and the aspiration to not try and engineer an architectural vision, but develop solutions, which work well at every level. For sake of argument: the shape of a roof may be driven by a certain ventilation strategy, while at the same time working well structurally and generating a beautiful space. Another example is the way building design should be sustainable, integrated with the urban context as well as the use of resources and energy – aspects which require a range of skills not necessarily pertaining to traditional building engineering disciplines.


This Material Evidence or knowledge you produce. How is that spread within the Firm? How do you recycle knowledge within the Firm?


The harvesting and dissemination of knowledge is the corner stone of development and innovation. In Arup, we have recognised the importance of knowledge sharing a long time ago and the result is a wide range of tools and platforms, ranging from skills networks and online forums to project databases and various forms of publications. We have also recently launched the Arup University, which takes our in-house training to another level with well-defined learning standards and collaborations with Universities.


At the seminar you mentioned the roadmap; what is the role of the roadmap?


Roadmapping is a type of management forecasting tool that can be used in a number of ways: as a method for capturing a time sequence of trends, targets and responses, as a living agenda covering tactical and strategic level objectives as a company-wide project plan. It can also act as an enabler for sharing market goals in supply chains and promotes team buy-in to corporate strategy and planning. We develop the roadmaps in workshops with key people in the firm and use the roadmap when prioritising our internal investments.


In the seminar you present the project “THE INTEGRATED BUILDING ENVELOPE” What is the main motivation for entering into such a project?


We were invited to a pre-project, exploring innovation and future building technology. It was an interesting opportunity to network and explore development opportunities. After a series of workshops, we proposed to create a consortium and develop new technology, employing new materials in a commercial building envelope application. It was a way of ‘pushing the envelope’ in terms of technology and the way facade systems are developed. Clearly we were also interested in the networking aspect.


At the seminar you said: It is because we feel that we can do better; according to seeking an alternative to aluminium! Could you elaborate on this professional drive for inventing better solutions?


We were not specifically seeking and alternative to aluminium, we were rather seeking to see how far we could get, using composites in a commercial curtain walling applications. Aluminium is the de facto standard in curtain walling frames. Because of the very high thermal conductivity of aluminium and the need to reduce thermal transmission, the frames need to be thermally broken which introduces complexity and cost. We started with a material with a lower thermal conductivity – a material with modifiable characteristics – and wanted to design around the properties of that material instead of mimicking conventional materials such as steel and aluminium. We set ourselves a series of very ambitious goals and worked to what we saw as a commercially relevant set of performance requirements.


The participants involved in this project represented a section through the supply chain. How does this group of different trade groups help to create new knowledge /Material Evidence?


We put together a consortium across the supply chain in an effort to develop technology, which was considered in a 360° view. We facilitated sharing of knowledge through a considered combination of workshops, site visits, and in-depth research and design. The sharing of knowledge and the development of concepts took place through use of sketching, modelling, and prototyping as appropriate. We went to great lengths to create an environment where information could be shared and the participants were free to contribute, using the most appropriate means of design communication.


What is the role of the demonstrator in this particular project?


We developed a number of models – both virtual and physical – during the project. We delivered what we called a visual mock-up on the conclusion of the first stage of the project (which was supported by Realdania under the Building Lab DK programme). The purpose of the visual mock-up was to communicate to ourselves and to our prospective clients ‘the look and feel’ of the new material in a novel curtain walling application. Clearly, an important element of this activity was to learn about the material and the challenges associated with the assembly processes.


You described a model on Buildability as a trinity of financial, technical and architectural importance. You said; “If you can solve this triangle you have a project”. Could you elaborate on the three aspects?


Did I? Well yes, when we deal with the relatively complex projects, we need to develop solutions which are technically feasible within the available budget, while ‘delivering’ the architectural vision. Compromises are inevitable and so the challenge is to develop a solution which meets (or exceeds!) the client’s brief, manage expectations along the way, and work closely with the contractors to minimise or avoid problems during construction. A typical example would be the delivery of a fluid form architectural building envelope in a relatively rational and economical way. The way you break down the fluid form into discrete elements is inevitably a compromise for the architect. Technically it needs to be feasible and buildable. And it needs to be realised within a given budget or it’s ‘back to the drawing board’.


At the seminar you talked about the many buildings being thought in two dimensions; you talked about the ability to think in build dimension, could you elaborate on this?


I was referring to the way details are traditionally drawn up in two dimensions whereas the real challenge is to resolve the interface details in three dimensions. The widespread use of CAD means the details may be mistakenly read as resolved, whereas they may not be fully developed at all. We say that ‘the devil is in the detail’ and this is particularly the case for complex building details. An experienced designer will be able to think the detail in three dimensions and also be able to sketch it freehand. The ability to sketch is key to ‘thinking on your feet’ and developing buildable solutions. There is a generation gap between, on the one hand, the wiz kids who master advanced CAD software but have limited design experience and, on the other hand, experienced designers with limited knowledge of – and interest in – CAD tools.


You talked about this “hands on” - material and - building process. How does that contribute to the development of knowledge?


Again, I was referring to the way your knowledge of materials and the way things are put together naturally informs the way you go about designing – whether you are designing building envelopes or other things. If you are exploring ways of using new materials in architecture - or using materials in a new way in architecture – it is probably a good idea to spend some time in the workshop or the factory to gain an understanding of their characteristics and behaviour. An example is our building envelope development project, exploring the use of fibre-reinforced polymers (glass fibre) in facades. The experience of cutting the material and testing different types of bonded connections gave the designers an appreciation of the limitations and the possibilities.


You presented a series of beautiful hand drawn detail drawings and discussed these as being a particular way of solving problems. How do you learn from this material evidence?


The sketches are a fundamental part of the development of facade details and communication between the various members of the design team and other stakeholders. The sketch is powerful as a very immediate means of communication and, while the format clearly sets out principles and subtle details, it also clearly shows that it is design in development. A CAD drawing may be seen as a final design even if, in reality, it is an early draft and full of flaws. A catalogue of sketches is a good starting point for development of solutions in response to project-specific requirements.


How does material evidence like the demonstrator intersect with other sorts of material evidence such as detailed hand sketches and cad drawings?


The hand sketches are part of the exchange of ideas and the development of solutions, which are then firmed up as detailed drawings and shop drawings. The mock-up allows the designer to explore the materiality and also experience the issues associated with working the material and assembling the components and the system. The mock-up communicates to other stakeholders what the concept is in a way which a sketch would only do to specialists.


Would it be right to say that the demonstrator tests solutions suggested by the sketches? What is a shop drawing?


The sketches are used to develop the solutions while the visual mock-up (or the demonstrator) is a physical representation of the preferred option. Shop drawings are the production information which is fed from the designers to the workshop or factory.


You talked about the sketch book as a way to document this process and to communicate it. What is the role of the sketch book?


The sketch book has become our preferred way of communicating our design process because it captures the process and sets out options and solutions in a condensed way. The graphical nature of the sketchbook appeals to architects and clients and helps steer the conversation towards design decisions. It is also a quite powerful medium for back tracking the process you have been through and avoid time-consuming discussions. The sketchbook usually does not capture ‘hard core’ engineering calculations, but deliberately seeks to provide examples of previous projects and suggest alternative solutions and recommendation.


How do you as a project manager create breeding ground for this kind of knowledge production?


It depends on the context. In our development project it was interesting to observe the ‘creative tension’ between the abstract and open-minded architects wanting to explore unchartered territory and – in sharp contract – the detail-focussed engineers, who were keen to agree on a solution to be able to go away and work it up in detail. I put the group in different situations and different settings to facilitate and encourage new perspectives and new collaborations. Sometimes it worked very well, sometimes it worked less well. Again, it comes down to people and it is intrinsically challenging to free up the most gifted designers to spend time on what can be seen as an ‘esoteric’ activity.


Would you re-use this method in future development projects?


Overall, I was pleased with the method. Ideally, the process would have been more intensive and the meetings would have been more frequent, but the idea of meeting in different locations and doing workshops followed by research and engineering activity worked well and – unsurprisingly – the group worked better and better as the project progressed.


Could you maybe specify or sum up on the overall method “workshops followed by research” in relation to our topic?


In this context the workshop is a forum for presentation of work carried out by individuals and working group, discussion and exchange of ideas, collaborative design and identification of areas for further research and development. The participants leave the workshop with an understanding of the challenges across the board and not just from their own perspective. Their efforts during the following stage will ideally be informed by considerations brought to the table by the project partners and the impact of their research will potentially be higher.


E.g. how is material evidence from the workshops evaluated or transferred into research or knowledge? And what kind of “engineering activity” follows after each workshop?


The activities in a workshop will span across presentations in various forms, enquiry, discussions and collaborative sketching, model building, and ad hoc testing. There is a sense of validation after the review in the workshop, but the theories need backing up by some analytical work such as engineering calculations and physical testing.


[Dr Kragh, interviewed by Maria Hellesøe Mikkelsen, Royal Danish Academy of Fine Arts, School of Architecture]

Are engineers undervalued compared with architects?

YES

Tristram Carfrae, Chairman, building design practice, Arup

"
Engineers are using modern computing power to optimise building designs; mechanise building construction; and automate their operation. At the same time our architect colleagues (those with greater sartorial elegance) use the same technology to create ever more elaborate, expensive and inefficient building forms.

By 2050, the world needs to double its urban capacity while halving each person's eco-footprint. We can rise to meet this challenge by engineering sustainable buildings; intelligent transport systems; smart utilities; and renewable energy sources (the value of which will come, of course, from their post-modern decoration).

We engineers outnumber architects 10 to one, yet you rarely read our thoughts and opinions in the press. Is this because we have to be absolutely right, beyond any shadow of doubt, before we dare venture into the public domain? Where is the judgment and intuition we use every day in deciding what to (and what not to) calculate? Engineering is, after all, the valuable art of making science productive; of providing luscious fruit from dry research; of solving wicked problems.

So it's partly our own fault that we are undervalued - if only we could talk! If we could be passionately eloquent about what we have done, and what we could do, then maybe we could set aside our anoraks and work with our architect friends to create a better built environment: one that is beautiful, functional and efficient; one that people want to live in; one that the planet can afford.
"

NO

Piers Heath, Environmental engineer, Foster & Partners

"
The valued engineer is the one that is a seamless part of the creative process of designing and building. If engineers are simply given the role of necessary support service to delivering buildings, rather than a force in shaping and influencing their design, they will be destined to feel undervalued.

As an engineer working at Foster & Partners, I am continuing a tradition at the practice going back to the 1970s where sustainable solutions to architecture and planning are designed by an integrated team that includes the expertise of in-house engineers.

Today that integration is more seamless than ever and includes not just engineers but specialist modelling teams, urban planners and others. We are part of the design board that oversees the entire portfolio of work, steering and challenging the architect teams, and bringing combined knowledge to the delivery of sustainable projects.

This integrated approach puts the engineers where they should be, centre stage with the architects. The debate then is not about being undervalued, but about being understood, appreciated and brought into the creative process. The real challenge for engineers is to create the opportunity to be involved in projects from the outset. When engaged in the early analytical stages of design, the impact of their expertise on quality and performance is persuasive.

As the integrated design process becomes the rule rather than the exception, no engineer should use the excuse of feeling undervalued.
"

[Building Design 15 April 2011]

Words #001

“The first American house built in war-time Java completely bewildered natives there. Instead of building walls of local bamboo, which is closely spaced to keep out rain while admitting light and air, the white man put up solid walls to keep out light and air, and then cut windows in the walls to admit the light and air. Next, he put glass panes in the windows to admit light but keep out the air. Then, he covered the panes with blinds and curtains to keep out the light too.” Ken Kerr, 1978.

Commodity + Firmness + Delight

In his influential work De Architectura, Roman architect Vitruvius talks about the three elements of Architecture: Commodity, Firmness, and Delight. There are interesting parallels to the nature of façade engineering in that the building envelope needs to fulfil the functional requirements and meet the specified performance criteria, while having a fundamental impact on architectural aesthetics and the intangible qualities of the resulting enclosed space. This, then, is perhaps one of the aspects that appeal to a new generation of technically minded architects and architecturally minded engineers? There is no doubt that the nature of façade engineering can be both complex and stimulating. Appropriate application of highly specialised skills is potentially the difference between a successful project and a less successful one.

[ Vitruvius _ elements of Architecture ]

The need for specialist input stems from the gradual transition from traditional to non-traditional methods and technologies. Technological progress and the industrialisation of the construction industry mean that the role of the Architect is changing from that of controlling the design through a profound knowledge of materials and techniques to a role of orchestration of a multitude of specialist skills, knowledge, and industry intelligence – possibly benefiting from façade engineering input throughout the various stages of the design process. The increasing complexity of the technology and the recognition that not many architectural practices can sustain in-house skills in every field resulted in façade engineering as a relatively new professional discipline. The first façade engineering groups were set up around 20 years ago in response to the need for specialist input on technically challenging projects. Façade engineering covers the grey area between the more traditional disciplines but also overlaps significantly with all of them, to varying degrees depending on the circumstances.

Welcome

The Facade Design blog has been created as a repository for information and views on the design of building envelopes and related matters. The relationship between architecture, building envelope technology, and design process is the focus. The blog will offer food for thought and - who knows - perhaps even offer a source of inspiration to those with an interest in these topics.