The purpose of the interviews was to gain general knowledge about how glass façade design is carried out today. The following experts have been interviewed.

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248 A^PPENDIXA-I^NTERVIEWS

A PPENDIX A I NTERVIEWS

1. L IST OF I NTERVIEWEES

The purpose of the interviews was to gain general knowledge about how glass façade design is carried out today. The following experts have been interviewed.

N° N

AME

C

OMPANY

S

PECIALISATION

1 Mr. Damian Rogan Eckelrsley O’Callaghan, London (UK)

Structural engineers, consultant.

2 Mr. Sergio De Gaetano Thornton Tomasetti, London (UK)

Consultants.

Façade engineers.

3 Mrs. Mercedes Gargallo Arup,

London (UK)

Consultants.

Façade engineers.

4 Mr. Alex Barmas Arup,

London (UK)

Consultants.

Façade engineers.

5 Mr. Jonathan Sakula Buro Happold, London (UK)

Consultants.

6 Dr. Mikkel Kragh Dow Corning Seneffe (Belgium)

Façade and architectural design consultants.

7 Mr. Giampiero Manara Permasteelisa,

Vittorio Veneto (Italy)

Structural and façade engineers. Manufacturers.

8 Mr. Enrico Giacopelli Enrico Giacopelli Architects, Turin (Italy)

Architects.

9 Mr. Francesco Buono University Estate

management, Pisa (Italy)

Engineers. Design and construction managers.

10 Mr. Bruno Persichetti AICE Consulting S.r.l. Pisa (Italy)

Engineers.

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2. L IST OF Q UESTIONS

Each interview was based on a framework of 14 questions: 7 of them focus on the design and construction process in general façade projects, especially concerned with glass. The other 7 questions are mainly related to renovation projects:

G

ENERAL

P

ROJECTS

A1. What does your Company do? What is your role?

A2. In what phase are you normally involved in the field of building façades?

A3. How many phases do you normally execute? Please choose among the proposed list or name them.

A4. How has the façade process been evolving? Looking at the table of façade design and construction process, please indicate you interest in cooperate with other stakeholders.

A5. What are the process steps, and how are they linked?

A6. What is the role of different stakeholders in this process? Is the cooperation effective?

A7. According to your experience, what are the weaknesses and the challenges for glass façade engineering?

R

ENOVATION

P

ROJECTS

B1. Which percentage of renovation projects do you usually find in your work?

B2. How many kinds of renovation classes can you define? Do you have a procedure to follow for the survey and diagnostic operation? (Structural, energy behaviour, map of decay etc.)

B3. How do you assess the actual energetic performance of a glass façade and is that measured afterwards?

B4. Is the demand for energy rating systems increasing or not?

B5. How did you manage to preserve the original appearance and the quality of the architectural monument?

B6. Could you please give us any suggestion, recommendation about the process

map? Which part would you improve/change/delete?

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The interviews were carried out in person (except one that was mainly developed by e mail) and consisted of a 1-hour meeting. The interviewees were asked to comment on the map, to correct and eventually integrate it, talking freely of the topics they consider to be most relevant with respect to the subject matter.

3. S UMMARY OF I NTERVIEWS – B RIEF M EMORANDUM

The following summaries of the interviews is based on the Author's handouts and therefore only represents an extract of the most significant issues that have been dealt with, without claiming completeness of the thought of the intervieews. A few questions, mainly concerning the discussion on process mapping, have not been reported, since the corrections were mostly graphics and have been assimilated into the final version of the mapping.

A1. What does your Company do? What is your role?

1 Eckersley O’Callaghan is an international structural and façade design engineering company, formed in 2004 by Brian Eckersley and James O’Callaghan after many years working separately as Chartered Engineers. We have developed an international reputation for our structural glass designs. We enjoy complex briefs and deliver solutions across a wide variety of forms, materials and project scales in the UK, US and worldwide. Currently, I am the Façade Group Leader at Eckersley O'Callaghan, London City.

2 Thornton Tomasetti was founded in 1956, and today is a 750-person organization of engineers, architects and other professionals collaborating from offices across the United States and in Asia-Pacific, Europe, Latin America and the Middle East. The company provides engineering design, investigation and analysis services to clients worldwide on projects of every size and level of complexity. We address the full life cycle of structures through our six integrated practices in Building Structure, Building Skin, Building Performance, Construction Support Services, Property Loss Consulting and Building Sustainability. Currently, I am the Vice President, Director of Building Skin at Thornton Tomasetti, London.

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Founded in 1946 with an initial focus on structural engineering, Arup first came to the world’s attention with the structural design of the Sydney Opera House, followed by its work on the Centre Pompidou in Paris. Arup has since grown into a truly multidisciplinary organisation. Most recently, its work for the 2008 Olympics in Beijing has reaffirmed its reputation for delivering innovative and sustainable designs that reinvent the built environment. (M): I am an architect and I work as senior façade designer at Arup, London.

(A): After a working period in the U.S., I am a façade engineer at Arup, London. My job is mainly related to building physics and thermal performance of cladding elements, as well as curtain wall detailing.

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5 Buro Happold, founded in 1976, is a professional services firm providing engineering consultancy, design, planning, project management and consulting services for all aspects of buildings, infrastructure and the environment. The firm now operates worldwide and in almost all areas of engineering for the built environment, with offices in seven countries. I am the Technical Director at Buro Happold, London. My main interests are façade consultancy and engineering, glass engineering and blast engineering.

6 Dow Corning was established in 1943 specifically to explore and develop the potential of silicones. The company provides performance-enhancing solutions to serve the diverse needs of more than 25,000 customers worldwide. A global leader in silicones, silicon-based technology and innovation, Dow Corning offers more than 7,000 products and services.

Currently I am the global façade and architectural design Leader at Dow Corning, Charleroi Area, Belgium.

7 Permasteelisa Group is a worldwide leading Contractor in the engineering, project management, manufacturing and installation of architectural envelopes and interior systems, with its headquarters at Vittorio Veneto. It holds a market share of 30% for curtain walls. The company was founded in 1973 as ISA by Massimo Colomban. The company grew throughout the 1970s and 1980s, which allowed it to acquire Australian façade maker Permasteel in 1987, after which it became Permasteelisa. In Permasteelisa I lead the Engineering Department in Permasteelisa Italy. My team deals with both structural and building physics topics in façades. My interests mainly focus on structural design.

8 The firm, founded by three architects, works since 1985 in the areas of architectural design, urban planning and industrial construction. It is based in Turin and provides advice and continuous supplies of individual projects to private customers, companies and public institutions. The firm, in parallel with more traditional activities, has developed special expertise in the design and management of buildings in the high mountains, in the design of public buildings, design and consultancy services in the field of industrial design of furniture, exhibitions and events in the field of hospital design. I am an architect with a strong interest in restoration, especially of modern buildings. I am a member of the board of DOCOMOMO, an international association that works for the preservation of the those buildings that belongs to the Modern Movement.

9 I am a civil engineer with a strong interest in history and in architecture. I work for the Engineering Department for the University of Pisa, Italy. The University Estate is composed of historic buildings, belonging to different eras: in my work I have dealt with medieval buildings, but also the recovery of industrial structures dating back to the 19^th and 20^th century, which needed to be adapted to the new needs of the present. In addition, in recent years the University has promoted the construction of new buildings and student residences, in which innovative technologies have been applied. Among these, I would stress the realization of the glass façade, supported by a network of cables, designed by Werner Sobek for the University residence "I Praticelli" in Pisa.

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10 A.I.C.E. Consulting S.r.l. is an engineering company based in Pisa, Italy, providing high-tech engineering services for the construction sector in Italy and worldwide. Our team is comprised of professional engineers, architects and technicians specialised in various fields, performing their activities using state-of-the-art hardware and software tools as well as sophisticated testing and measurement equipment. The Company was founded in 1990.

Today, through the sub-divisions of the Technical Department (Design, Diagnostic Surveys, Monitoring), the Company provides a wide range of engineering services from planning and site management to structural diagnostics, monitoring and testing of civil and industrial constructions, bridges and roads, technological systems, as well as historical and listed buildings. I am a civil engineer and I work as a project manager in A.I.C.E. Consulting.

A2. In what phase are you normally involved in the field of building façades?

A3. How many phases do you normally execute?

1 Normally we are involved by the architect, who want to initially test the feasibility of his/her project idea. In other cases, as was the case for Apple, was the Client himself to desire the development of the project idea. This happens only when the Customer, while not a technician, has a precise definition of the goals he wants to pursue.

2 The façade consultant can be involved by several subjects: client, architect, contractor (for design & build contracts). In the UK, Stage A, B of the project are normally related to feasibility studies. Thereby, the work of a façade consultant usually starts at Stage C/D.

There is a constant interaction with the architect/AE team, especially as regards some topics outline in activity A2:

 Form/shape.

 Material palette.

 Performance.

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The services that we offer can range from feasibility study, to the preparation of documents and shop drawings. Everything we do, from concept design to implementation and renovation, is design-led and underpinned by technical rigour: Arup has different sectors concerning with materials, building physics and building performance and systems. Each of us, along with your workgroup, deals with a single aspect and detail goes into trying to coordinate with other disciplines.

5 We usually develop a design idea or a concept, to the final version with detailing. Our work aim at advising clients on the best way to develop, design and procure the building envelope, using our knowledge of the full supply chain to provide high level technical advice across the whole design process, including the choice of materials and systems.

6 Dow Corning is a global leader in the development of silicon-based innovation for the high- performance building industry. Our work is especially focused on the development of

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technological solutions, with the development of details up to the executive level. This determines the use of standard solutions, or the development of the appropriate solution for the single project, “custom-tailored”. Taking a holistic approach, Dow Corning brings together expertise from across the company to help customers find solutions to a wide range of high performance façades (and buildings) challenges.

7 We usually start working on the project after the initial design phase. Normally, there is a study that has been already developed from an architectural point of view. We offer the technical solution during the tender selection: i.e. how to achieve a sustainable intervention in terms of structural, functional, energy level, manufacturability. The previous architectural analysis usually does not go into detailed aspects as well. Then, when the contract is awarded, we develop the solution up to the execution phase and construction.

8 Our work is mainly related to project design, implementation of the preliminary and final design of the façade, with the collaboration of technical specialists and manufacturers, who then develop the technical specifications.

9 The main task of the technical University Office is to establish, initially, what are the requirements and the general aims. Throughout the course of the project, we are required to check for any deviation from that baseline, both technically and economically. Finally, the other main task consists in the management of the construction phase, with the direction of the work on building site.

10 The company can perform diagnostic surveys (structural and building services) and design.

So, we can offer different services, from surveys, monitoring, as regards existing façades, up to the detail design. Of course, with regard to the definition the façade systems, we turn directly to the producers and collaborate with them in the development of the design.

A4. How has the façade process been evolving?

A5. What are the process steps, and how are they linked?

1 Decision-making is much more difficult when it is done sequentially and with only selective information available. The competent people dealing with the façade (or the building envelope) are referred to as façade engineers and the relatively new field is becoming increasingly important as part of an integrated approach to design and delivery of buildings.

Notwithstanding the impact of facades there is a lack of industry-wide regulation of the professionals in this field.

2 The typical construction process often puts the burden (and risk) of engineering the façade on the vendor, particularly under design-build contracts which then carries a contingency cost. One needs to involve the contractor and manufacturer early on, as part of the design team. For example, clients could pre-qualify the curtain-wall contractor and involve their expertise early on toward designing a least-cost solution that includes ease of construction,

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appropriateness and availability of existing components.

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There is an architectural trend toward greater transparency. People want a good visual connection to the outside, but the thermal requirements kills that transparency. With high high-performance systems, i.e. double-skin façades as an example, one can improve thermal performance and gain transparency. There is often a need for an integrated approach and an improvement in communication, among the design team, contractors and the manufacturing.

5 As with many architectural trends, understanding the reality of building performance in the field as compared to design intent is often difficult to ascertain. We have been particularly interested in this emerging trend because prior simulation studies have shown that it should be technically possible to produce an all-glass façade with excellent performance although it is not a simple challenge.

6 Technological progress and industrialisation of the construction industry means that the role of the architect is changing from 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 aarchitectural practices can sustain in-house skills in every field resulted in façade engineering as a relatively new professional discipline.

7 The field of advanced façades is a rapidly evolving work-in-progress. The façade is of paramount importance in terms of building performance and is an important architectural element, ranking alongside building site and form. It is not only the aesthetics that make the façade so significant - depending on a series of factors such as complexity, materials and finishes, performance, and magnitude and location of the project, the façade can account for anything between 15 and 25% of the total construction costs and represent a substantial part of the technical and commercial risk on any given project. In this context, the role and the importance of the façade engineer is increasing.

8 From a purely architectural perspective, the use of all-glass facades combined with advanced technological solutions is a rich, modern expression of form and function. The main aspects of the actual process are, in my view:

1.Clarify design needs and constraints.

2.Surveys and assessment of existing conditions.

3.Materials and finishes study.

9 The traditional construction process, which involved various activities performed in parallel by different designers, is no longer sustainable. For the success of a project, a multidisciplinary approach is required and a strong coordination by the Project Manager in essential.

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10 Successful projects generally depend on a high degree of collaboration across th design team and throughout the supply chain. Where the collaboration and the contractual set up is handled competently, value can be added through excellent technical and aesthetical detailing and risk can be managed in terms of cost and programme. Not willing to invest more at the beginning to realize much larger savings later is a poor business strategy. A frequent reason for this is the fact that those who control construction budgets are not the same individuals or groups as those who control operation and maintenance budgets. They have no incentive to invest in the future of the building and have every incentive to minimize what they view as their expenditure. It takes an informed and involved owner to resolve this contradiction.

A6. What is the role of different stakeholders in this process?

Is the cooperation effective?

1 There is a strong relationship between the façade consultant and the design team, especially during the phases of decision making and select renovation options. Mechanical and electrical engineers are required to give the information and the parameters to the façade consultant, therefore their contribution is crucial to obtain the correct input for the project.

2 The leader of the entire process is generally the architect/AE team. Unfortunately, architects typically involve façade engineers later in the design process, sometimes as late as 50%

design development of the project. For advanced façade-building systems, a team effort between the architect and engineers is required to solve integrated design challenges, and to maximize these integrated performance benefits we have found that the team must work together from project inception.

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Integrated façades are typically very complex systems that require a high degree of technical understanding that range from thermodynamics and material sciences to air flow to lighting and daylighting to HVAC equipment and systems. Each of these has to be considered in its own right; consideration of one at the expense of another can result in systems with inappropriate performance, a malfunctioning system, or in the elimination of the idea.

5 Many parties that are in involved in building design, procurement and operation are also active participants in decision-making that results in integrated façades. These include the client, the architect, the façade systems specialist, the mechanical engineer, the cost estimator, the fire engineer, the structural engineer, the construction manager, the lighting consultant and the value engineer. Each decision maker plays a different role and often has different (possibly conflicting!) goals that sometimes make decision-making difficult.

6 Agreement among decision makers is harder to reach if their backgrounds and professional experience are heterogeneous. For instance, the architect may propose an integrated façade that poses additional requirements on the structural system design, which in turn may

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increase construction cost; the client may object to the higher cost and, in the attempt to reduce project cost, the project manager may eliminate the integrated system altogether.

7 Simultaneous discussion of all parties that need to be involved with the same information available to everyone is the most effective way to reach agreement and make decisions. All too often parties join the decision making process while it is already in progress; they often miss the reasoning for the previously made decisions, are often given only the information someone else considers “pertinent” at the time, and are in general significantly less informed about the issues than some other participants. It is also critical that the design team educate the contractors (and specialist subcontractors) as well.

8 The design of a façade requires the involvement of many professionals and the intermingling of complementary disciplines. This should happen during the design phase. Unfortunately, the coordination does not work properly and there is a loss of information that leads to conflicts. An additional problem occurs with the interaction with external Public Offices. In addition, other problems are recorded during the execution phase, in which often the interests, the time schedule of the client, the designer and the contractor can conflict, especially in the case of sub-contractors.

9 In my experience, one of the main problem regards the coordination between the design team and the contractor and subcontractors. The important issue consists in the respect of all the requirements that are outlined in the technical specification. The client (i.e. the University Estate Management) needs to be made aware that warranties can become a problem when different vendors provide different components of the built-up façade assembly. The specifications must carefully delineate who does what and who takes responsibility.

10 The most commonly reasons that complicate the design and construction process are the lack of communication among the stakeholders and the lack of adequate supporting information, and insufficient technical knowledge about the alternative. Implementation of façade systems must consider the same criteria as other projects: project economics, impact on tenants, and impact on building maintenance and operations. Two critical issues are the cost and quality dealer support, and the ability of building staff to maintain, operate and to some extent optimize the system.

A7. According to your experience, what are the weaknesses and the challenges for glass façade engineering?

1 An evaluation tool simple enough to input some rough data shall be useful, such as a sort of checklists and general instructions. In addition, first cost is usually the criterion given most consideration in decision-making for integrated façade systems. This is unfortunate, as focus on first cost typically fails to consider the benefits of particular investment on life-cycle cost.

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All too often a building element that is more expensive to install than some other alternative works better and reduces operating, maintenance and replacement costs in the future use of the building.

2 The implementation of BIM technologies can be useful for new construction, especially to define the shape and the geometry of the façade. In renovations and refurbishments the development of other software can be more useful, such as some apps for the architectural surveys.

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The development of design tools that can help one quickly understand whether a given strategy is viable for a particular site. It is important to understand that integrated façade systems do not have to cause higher overall building cost. If a certain level of building performance is a goal, an integrated façade system that achieves that goal may actually cost less than an elaborate building skin that may or may not provide comparable performance.

For example, a naturally-ventilated building may allow the building owner to downsize or eliminate the HVAC system resulting in a lower overall building cost.

5 Computer based tools can aid in decision-making. While no tools designed specifically for simulation and analysis of performance of integrated façade systems are available on the market today, some of the available general computer-based building tools can serve the purpose rather well when utilized by skilled staff who understand the capabilities and limitations of the tools.

6 These are computer programs that can analyse or simulate a given aspect of performance of integrated façade systems. For example, “whole building energy tools” can simulate the energy performance of the entire building over periods of time, so one can see the effects of a particular integrated façade system on the building’s energy consumption. Or,

“daylighting” tools can show the impact of natural light that the façade system allows to penetrate the building on the consumption of electricity from electrical lighting.

7 Planning, design and procurement processes and time lines and schedules need to be considered. The delivery of integrated façade systems often is in conflict with standard building procurement practices that may make the entire plan impossible to execute. This is particularly true if the proposed system adversely affects time to occupancy. Technical merit and constructability of the proposed integrated façade system can be an issue. The proposed system may include components that have not yet been proven to work together under some particular condition, may be difficult to construct in the given location, or may cause general construction problems for the building. This is particularly true if deployment of new technology is involved.

8 Given the many different possible circumstances, conditions and decision-making issues one can face in considering and proposing an integrated façade system for a building, the decision-making group. Chances of success increase if the owner and the architect understand the benefits of integrated façade systems to the extent that they are willing to

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put these systems “off limits” during project value engineering. If change and cost cutting is unavoidable, they may still find a way for the remaining solution to work within the needed performance boundaries.

9 Integrated façade systems (or any other part of the building) sometimes do not work as expected because of component substitution during construction. The designed and specified system components may not be timely available, or alternatives may cost less;

substitute components are used without consideration that they may not perform the way the original is supposed to. This can result in serious erosion of system performance that is hard to trace if the component is small and difficult to reach. To avoid such problems, one should commission any integrated façade system before delivering the building for occupancy, as should be the case with any other important system in the building.

10 The use of software that can give a quick ad “rough” solution can be really useful, especially during the first stages of design, in order to give the right direction to the design development. Such tools can serve a dual purpose: to predict the performance of components, integrated systems and the overall building, and to show why a given decision has a given impact, as well as to bring in the forefront the important underlying assumptions. Judicious use of such tools in the decision making process can provide answers to disputed questions, and can demonstrate cause and results of decisions to those who are less knowledgeable about the issue.

B1. Which percentage of renovation projects do you usually find in your work?

B2. How many kinds of renovation classes can you define?

1 The percentage, especially in European panorama, is more or less 50%, whilst in the U.S. and in other foreign countries we normally deal with new construction. Heritage constraint seems to be the first and most significant issue to define the approach to the project and to state what I can do or not. The definition of heritage constraints is normally done by the architect, but sometimes the facade consultant can be required to carry out the report. In my view, there are two main attitudes:

 In historical bldgs, you have to keep as much as possible.

 In non-historical bldgs, you have to get rid of much as possible.

The UK approach to renovating is generally undertaken to meet new energy regulations; the renovation implies both to replace windows and HVAC systems. Another important constraint is related to the future use of the bldg and to the client requirements: the more stringent limits concern energy requirements. Residential and industrial are not very relevant, while offices and other facilities are significant.

2 We mainly deal with new buildings. But, especially in European market, there are many reasons that can be addressed to renovate/refurbish a façade.

 Marketing (new image to the building);

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 Change of use;

 LEED upgrade (major rentability);

 Security upgrade (bomb blasting).

Main types of buildings can be renovated; we usually work on:

 Office facilities;

 Government buildings;

 Healthcare and schools/academic buildings, but they are much rarer, since they are normally low-budget.

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The most pressing requirements and indeed opportunity is to upgrade façades that are between 30 and 50 years old. Sustainable architecture, with goals of improving connections between indoor and outdoor space and occupant controllability is another factor driving this approach. As an example, Arup has developed in the UK the feasibility of upgrading a number of existing hospitals. It has been found that facade-led upgrades revitalise older buildings (Philip King, ARUP). The use of the buildings during the refurbishment is often required as a constraint.

5 The major complexities of renovation/refurbishment projects are related to evaluate what you have and what are the façade existing condition. The refurbishment project usually goes throughout different stages:

1. To carry out a general desk study/random surveys.

2. To propose further work to verify options/approaches.

3. To develop the designing solution.

6 The renovation of existing buildings with the installation of new high-performance facades is increasing, especially in Europe, because there is an interest to the building’s ability to meet the needs of the occupants: there are codes for access to daylight and fresh air in many EU countries, there is a different cultural mentality in the EU, since occupants refuse to work in buildings that do not supply what they see as “requirements” of a healthy work environment.

7 The market of façade renovations is more extensive in Europe, but also in the United States, where specific laws require the periodic review of the actual conditions and performances of envelopes, especially in the city centre. The main requirements that affect renovation projects are:

 Planning/Heritage constraints.

 Architectural statements.

 Desired look of the facade.

 Conceptual and renovation statements.

 Previous buildings/facade of similar type.

Sometimes the monitoring and tests are required. In other cases we can get rid of the entire façade but it depends on the historical values of the building. Interactive discussion with architects, client/tenant representative are fundamental.

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8 When we deal with restoration projects, we always try to understand, in accordance with the Heritage Building, what are the required constraints and objectives, in order to choose the most appropriate design strategies. They vary of course depending on the characteristics of the façade, and of the entire building, its location, the future use. In any case, the strategies can vary from a conservative approach, to the replacement of the envelope with similar elements; sometimes the architect can even choose to use a completely different and innovative architectural language.

9 The University Estate consists mainly of existing buildings. Interventions can range from local repair, up to the complete replacement of the elements. Technical performance specifications shall be included, such as:

 Acoustic;

 Structural;

 Fire;

 Weathertightness.

10 Our industry includes both the design of the new diagnostic tests on existing buildings. Life time of façades is about 25-30 years, thereby there are several envelopes that shall be upgraded to meet new standards and uses. In case of refurbishment, the client is usually more involved, especially at the early stages of design. Sometimes the refurbishment project involves purely technical problems. In case of historic buildings, the project is more similar to a real restoration, whilst for buildings that are considered “historically less important”, there is a greater freedom in the definition of façade profiles and glazing.

B3. Do you have a procedure to follow for the survey and diagnostic operation? (Structural, energy behaviour, map of decay etc.)

1 The consultancy phase is carried out before starting with the design and implies an option study on big scale with rough surveys. No models are developed in consultancy phase. The steps do not follow a standard.

2 Before starting with the site surveys, a more superficial “condition survey” is usually carried out (quick and dirty!). It involves visual analysis, some general considerations and the final report to the client.

This kind of work may be required for different reasons:

 Local law 11, NYC: the owner are required to provide periodical inspections (every 10 years) on external walls and roof.

 London: insurance companies usually require inspection to assess the condition of the building.

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As built drawings are often the main source of information in the initial phase of the work.

Also the information provided by the energy or the building manager can be useful at this stage, especially if energy improvements are the goals. No models shall be produced at this stage.

5 At the very beginning, the desk study shall imply several actions to assess the existing condition of the building; some of them are:

 Literature review (as built, drawings, reports, specifications);

 Site visit and random facade inspections;

 Functioning of the building or of any related problems (ask the building manager).

After that, the facade consultant write a report to the architect/client, evaluating the condition and recommending some general options for further work.

Only if the architect/client accept to go ahead with further work, then some additional tests/surveys must carried out. It implies:

 Thermal analysis;

 Laboratory studies for materials (i.e. evaluate the condition of the structure).

6 Our engineers work closely to bring the benefits of high-level technical knowledge to the design of the envelope. With sustainability now a key regulatory requirement, we carefully analyse the environmental “behaviour” of different façade designs using advanced techniques such as thermal modelling, wind analysis, acoustic design, solar and glare studies.

7 When dealing with existing buildings, we often perform our surveys, with our own teams, in order to integrate the survey already proposed on tender documentation. For instant, in a recent façade renovation that I followed in France, on a building by Jean Prouvé, we had to initially detect and verify the location of deck slabs, columns, etc.. We had the original as- builts, but, as often happens, they were imprecise and not very reliable. So, in these cases there is often an intersection at an earlier stage, which usually we do not perform.

8 Initially, it is important to search all the available documentation about the façade and the building. Then, our survey operations generally consist in the definition of the geometry of the façade, the details, the mapping of possible states of decay, trying to identify the causes.

This is also the minimum documentation to be submitted to the Building Heritage: it is the base to develop and agree on the possible future design solutions.

9 We usually carry out inspections, surveys where necessary, but we employ the services of experts for the definition and conduct of diagnostic surveys.

10 Our company has developed a fairly standardized procedure for making surveys and investigations, mainly structural. This involves, in addition to research the available documentation, the preparation of a study plan, which is agreed with the customer.

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B4. How do you assess the actual energetic performance of a glass façade and is that measured afterwards?

B5. Is the demand for energy rating systems increasing or not?

1 The percentage of glass in the façade is mainly considered in terms of:

 U value (insulation)

 G factor (solar control)

Mechanical and building services engineers shall give the numbers and the requirements to prepare the first evaluation. Manufactures data are mainly important for to assess the requirements the access machine. LEED and energy rating systems are becoming an important basis for the development of these types of work.

2 A more detailed condition survey is eventually carried out later. Sometimes the state of the façade cannot be assessed locally (skyscrapers in NYC). The technical consulting can also be a single activity, not necessarily followed by a project. Some test shall be carried out, concerning:

 Glazing (GASP® Surface Stress Polarimeter, for measuring surface stress in heat- strengthened and tempered glass);

 Sealants/fixing systems;

 Frame.

Usually some simplified models are assessed by software like WIS, Energy plus (but only a rough modelling). Rating systems for sustainable design are one way of quantifying the potential sustainable savings and is rapidly gaining recognition by the design community as a viable convincing mechanism.

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The glazed areas of a facade raise a number of issues that need to be assessed:

 Daylight

 Shading devices

 Controlled use of natural ventilation (especially for taller bldgs.)

 Security against intruders.

We normally perform a rough survey at the first stages of design. We do not build models or calculation. Only during the following steps, we prepare more detailed technical solution.

The boom of certifications has been recognized as one of the decisive factors when considering the most important aspects of a façade refurbishment: the approach of such systems often requires to assess the existing performance of the façade and of the entire building, that need to be considered as the baseline of the project. This is the benchmark to measure and quantify the improvements. In addition, Façades present the opportunity to incorporate energy-generating technologies. There has been little adaptation of this to date in renovations.

5 No software models are generally generated at this stage of design. The main issues that

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need to be explored in case of refurbishment are mainly related to improving INSULATION and WEATHERTIGHTNESS. We may propose to design/analyse façade performance impacts for the 1% or 2% design condition only rather than a full-blown investigation of the building’s performance over a typical year. The level of analysis proposed is dictated by the client’s desire and level of design team’s need (depending on the complexity of the system) to understand the implications of the façade system design under typical operating conditions.

6 The company is collaborating with industry professionals to develop solutions to improve the energy efficiency of buildings, and improve the health and safety of building occupants. Dow Corning High Performance Building Solutions include proven materials for structural and protective glazing, weatherproofing, insulating glass, window and door fabrication, and building materials protection, as well as innovations for high-efficiency insulation, LED lighting, thermal management systems, and the incorporation of photovoltaic cells and solar panels into building design.

7 To fully understand how such a system is working, it is necessary to measure and monitor the performance of the system. This requires decisions on what to measure and monitor that will define the performance in view of the original system performance goals; it requires instrumentation, monitoring equipment and staff to do the work. Consequently, such activity requires a budget that must be planned for as part of the original building construction budget. Successful efforts in including integrated façade systems in a building always require a driving force in the decision making process. Such forces can be occupant driven (to reach higher level of comfort, for example), or occupant driven as perceived by the owner. The owner may feel obligated to be “green” or may strive for a specific LEED rating for the building. Stricter energy codes may also be a driving force.

8 We generally do not realize the investigation phase, and we delegate to an external team.

More clients are interested in obtaining a positive LEED rating. In some cases, cities or agencies are mandating minimum LEED ratings.

9 Operating and maintenance costs are other important criteria. If planned, designed and installed properly, integrated façade systems usually result in lower overall operating costs.

The savings are mostly achieved from a reduced overall energy consumption in the building.

Properly designed systems are usually easier to maintain because maintenance is accounted and planned for, specific performance can be monitored, and problems and malfunctions may be detected sooner.

10 Without measurement of system performance one can never be certain how well a given system is working. This is particularly true of integrated façade systems; since relatively few have been installed and monitored to date, too little empirical knowledge about them is available to be universally useful. Specific performance goals can be important criteria in decision-making and may be the catalyst in designing a specific integrated façade system.

These can be a better energy performance of the building, better or specific response of the building to its surrounding environment, increased occupant comfort, lower operating cost, a “greener” building (i.e., a higher LEED rating), attained publicity, etc.

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B6. How did you manage to preserve the original appearance and the quality of the architectural monument?

1 When dealing with an historical building that needs to be preserved, the most important issues to be considered are:

 Function: can I fit the new function in the existing building?

 Daylight (especially for office, schools etc.): sometimes an environmental model can be developed

 Structural: how do the existing facade perform? What are the failure criteria?

 Layout of the building: what are the thermal insulation requirements?

 Image of the new curtain wall: in terms of architectural trends, client expectations.

Access and maintenance are central issues to be considered at this stage, in terms of:

a) Material selection.

b) Maintenance equipment and access strategy.

2 Select renovation options: the first activity is to have a meeting with the Planning Officer of the City Council. Historic preservation is a central issue and can modify the design approach and the different technical solutions. It is advisable to split the map into two:

 Listed buildings.

 Non-historic buildings.

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AND

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In selecting options, the first step is the definition of materials and systems. Over cladding and recladding schemes shall be introduced: many aspects of the facades’ design and performance need to be considered together. An engineering–led approach is essential in order to optimise design and without calculations and simulations, there is a considerable possibility that some information shall be loose. In addition, a particular issue is the need for accurate energy modelling in order to inform decision making: only in this way it is possible to assess and balance the requirements, that my often conflict, between the need to reuse the building, and to respect its historical image.

5 There are several design approaches and degrees of intervention on the existing buildings.

The choice of this approach depends on the type of building, the choices of the Customer, regulatory requirements and the constraints imposed by public offices, such as the Planning Office and the Building Heritage. The general recommendations can be:

 To repair;

 To overclad;

 To reclad.

Recladding basically means to replace both glazing and frame. Over-cladding implies also fire implication, since the behaviour of the cavity must be addressed. When evaluating different renovation options (activity A2), the design has not already started. Then, the main issues to be explored are: structural evaluation; acoustic implication; condensation study (external/internal); materials (corrosion for iron, timber, paint finishes etc.).

6 The challenge of implementing this system appeared insurmountable because of the difficulty in meeting the requirements of the energy code.

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7 Our Group can develop a specific technical solution for a single renovation project, in order to reach the desired outlook and to demonstrate compliance through technical interpretation. Permasteelisa has developed its own applied software to determine the U- value and SHGC of the façade assembly. In addition, a full-scale mock-up can be constructed, tested and evaluated. The, the testing methodologies, data and supporting documentation can be sent to the accredited laboratory for validation.

8 Our approach usually begins with the collection of historical documents, the original drawings and all the available documentation. Historical research often is the starting point to understand what are the design constraints, and then to choose what has historical value, and therefore should be retained, and what should be replaced.

9 We ensure that the approved design documents meet all regulatory requirements, and that the relevant approvals of Public Offices have been acquired. Also, we have to be vigilant during the construction phase. Of course, the approach varies depending on the characteristics of each building.

10 Our methodology for the investigation of a historic building first starts with the definition of general project constraints and objectives. The available documentation is then collected and selected. If diagnostic tests are scheduled, an investigation plan is established, that must be agreed and approved by the Client. The constraints imposed by the Building Heritage are very important. After considering all these factors, we define the intervention strategy.