Technology Hardware & glazing systems
Trends in curtainwall design

Curtainwall designs have evolved considerably since the first framed
wall was introduced to enclose a building envelope, spawning new
variations of high performance glazed curtainwall systems. Today’s
curtainwall systems allow architects to design durable and cost
effective cladding solutions that meet specific performance and
aesthetic criteria.

The assembly lines at Aluminum Curtainwall Systems in Kamloops, British Columbia. Photo By Kamil Kropac, Courtesy Of Aluminum Curtainwall Systems.

Q:How has the process of curtainwall design and manufacturing changed over the last 20 years?

A:Kevin Fairchild, product marketing manager, Kawneer Company:
“Technological advancements in CAD (computer aided design) have greatly increased our design capabilities while allowing us to develop products much more quickly. Automation is playing a larger role in manufacturing and we have seen a real improvement in production.”

A: Frank Luciani, president, Aluminum Curtainwall Systems:
“In our view the worldwide quality control initiatives (the ISO 9000) helped curtainwall companies to better understand their core business with focus on streamlining the design process, improving quality control measures in their plants and therefore becoming more efficient.

“Operating in a tightly quality controlled manufacturing environment results in more sophisticated products being produced which are capable of achieving higher performance levels required in today’s ever challenging construction market.“

A: Steve Gusterson, pre-construction design services, Alumicor Limited:
“Twenty years ago, curtainwall in Canada was really in its infancy. There were fewer manufacturers of systems, the systems were comparatively primitive and there were few options.”

A: Tony Menecola, owner and president, Applewood Glass and Mirror:
“Curtainwall contractors are more aware of the proper rain screen design of curtainwall and what the proper procedures are to install a leak-free system. Trends are now more towards unitized (pre-glazed) systems. Unitized requires a much larger capital investment by the curtainwall contractors in facility and equipment. In my opinion the benefits of unitized to the contractor as well as the end-user are well worth the investment.”
Q:What have been the most significant technological advancements in this market and what are the driving factors behind them?

Stockton Arena, Stockton, California, features a Kawneer 1600 SS (Screw Spline) curtainwall.  Photo Courtesy Of Kawneer Company.

A: Kevin Fairchild, product marketing manager, Kawneer Company:
“Automated machinery has significantly reduced the time needed to fabricate product while also increasing product quality. Sealants/silicone have also improved greatly, leading to improved product life and increased design capabilities.”

A: Frank Luciani, president, Aluminum Curtainwall Systems:
“The development of high performance ‘neutral’ coatings on glass, driven by more stringent energy codes, has certainly influenced the way glass façade looks today. These coatings are ‘neutral’ in appearance, thus having a minimal impact on the color, tint or reflectivity of the glass.”

A: Steve Gusterson, pre-construction design services, Alumicor Limited:
“There are many, but I believe thermal improvement of systems to be the most significant technical advancement. This is being promoted by architects and curtainwall consultants but I think much of that is a result of end-user concerns about their buildings performance and longevity. Concerns about the potential for development of mould in hidden areas are much a part of that.”

A: Tony Menecola, owner and president, Applewood Glass and Mirror:
“Definitely ‘unitized curtainwall’ vs. the old ‘stick system’. Better quality and quality control as well as speed
of installation.”

Q:How are architects and designers challenging curtainwall manufacturers and installers with their designs?

A:Kevin Fairchild, product marketing manager, Kawneer Company:
“Architects and designers are always pushing the envelope by wanting more performance and improved aesthetics. As a manufacturer, you have to constantly improve your products by making them more versatile in both design and function. Installers face a lot more variety/customization in installation jobs.”

A: Frank Luciani, president, Aluminum Curtainwall Systems:
“Visual clarity continues to be the prime importance in glass selection, while challenging building/façade geometries continue to provide new opportunities for product development. Building with ‘twisting’ floor plans, inverted facades incorporating unique glass in-fills, ‘sustainable design’ curtainwall systems with integral sunshade devices all continue to challenge the manufacturers and installers.”

Shop glazing curtainwalls. Courtesy Of Applewood Glass And Mirror.

A: Steve Gusterson, pre-construction design services, Alumicor Limited:
“Without the challenges put to us by designers, the systems would simply remain static. Wider mullion spacings, offset mullion spacing and the greater movement of lighter building construction are always a challenge.”

A: Tony Menecola, owner and president, Applewood Glass and Mirror:
“Panels (frame sizes) are getting larger and forcing contractors to become more creative with installation methods. We have installed triple glazed unitized panels as big as 10 feet by 14 feet and weighing over 1500 pounds. We approach all jobs from the perspective ‘can we pre-glaze it?’”

Q:Where are trends heading for pre-glazed or unitized curtainwalls in the future?

A:Kevin Fairchild, product marketing manager, Kawneer Company:
“As the shortage of qualified labour continues, more and more companies are switching to pre-glazed and unitized curtainwalls. These products are also fabricated/glazed in a controlled environment, which leads to better quality. I believe that we will see a large increase in sales of pre-glazed and unitized curtainwalls within the next three to five years.”

A: Frank Luciani, president, Aluminum Curtainwall Systems:
“In our view, here are some the trends we see in our market area: transparency of the glass façade; design flexibility to suit more complex façade shapes; energy efficiency and incorporation of the ‘smart curtainwall technology’ and the curtainwall façade as a major element in the design of ‘zero-energy buildings’.”

Packing unitized curtainwall panels for shipping at Alumicor’s facility in Toronto, Ontario. Photo By Steve Gusterson.

A: Steve Gusterson, pre-construction design services, Alumicor Limited:
“With a dwindling work force and the need for better quality control, there is no question that pre-glazed and
unitized systems will become as popular in Canada as they have in many large US markets.”

Q:How have the advancements in new coated glass products impacted the curtainwall market?

A:Kevin Fairchild, product marketing manager, Kawneer Company:
“Coated glass products have had an influence by offering architects and designers more aesthetic options as well as offering the building tenants/owners privacy and personal protection.”

A: Frank Luciani, president, Aluminum Curtainwall Systems:
“The ‘neutral’ coatings when combined with a substrate such as low-iron glass, or low-iron patterned glass can produce very ‘transparent’ façade, which brings new opportunities for artistic expression in modern architecture.”

A: Steve Gusterson, pre-construction design services, Alumicor Limited:
“Only in helping to achieve greater thermal performance of the combined products or what could be called ‘the total system’.”

A: Tony Menecola, owner and president, Applewood Glass and Mirror:
“Yes. You are starting to see far less spandrel area in office buildings. The excess light is handled by the use of sun shades and light shelves. Heat gain and loss is where new high performance low-E coatings help in this design. Architects are moving away from the ‘mirror box’ that once was the norm. Designs now are more transparent.”

Q:Curtainwalls sometimes fail. What are the most common causes and how can they be prevented?

Maple Leaf Foods head office in Mississauga, Ontario, was built using Alumicor’s BF2000 Unitized and 2500 Series stick curtainwalls. Photo Courtesy Of Alumicor.

A:Kevin Fairchild, product marketing manager, Kawneer Company:
“Most of the time this is contributed to improper installation and/or the wrong product selection for the
application. Manufacturers must make sure that their customers understand the correct product applications and that they are properly trained on the correct installation methods.”

A: Frank Luciani, president, Aluminum Curtainwall Systems:
“In most cases the causes of curtainwall failures are inadequate quality control measures in the plant and/or the field and workmanship issues resulting from inadequate training.”

A: Steve Gusterson, pre-construction design services, Alumicor Limited:
“Failures in a proven/tested curtainwall system are most often due to poor workmanship in either fabrication or installation. Sometimes, however, it can be attributed to a specific detail in a particular project design that was either overlooked or not addressed properly.”

A: Tony Menecola, owner and president, Applewood Glass and Mirror:
“Like most problems, usually human error as opposed to poor design. This is easier to control in shop conditions because it’s a more controlled environment then the construction job site, especially during the winter months. This is one of the benefits of unitized curtainwalls.”

Q:How has LEED (Leadership in Energy and Environmental Design Green Building Rating) influenced this market?

A:Kevin Fairchild, product marketing manager, Kawneer Company:
“We are seeing a big push toward ‘green’ buildings and LEED has really been instrumental in bringing this
concept to the forefront.”

A: Frank Luciani, president, Aluminum Curtainwall Systems:
“LEED has become part of the building design. The building envelope gives the designer great opportunity
to achieve ‘sustainable design’ by incorporating various passive or active solar control devices in their approach to balance energy efficiency of the mechanical system for the entire building. Collectively, we need to look at the building façade as actively functioning/living part of our environment and not as a passive ‘shelter’ from our surrounding climate.”

A: Steve Gusterson, pre-construction design services, Alumicor Limited:
“It has provided a new bandwagon for manufacturers to jump upon. I have yet to see any manufacturer seriously consider LEED in their latest designs. That is probably due to ignorance on the subject more than anything else. I’m not sure that our industry understands what contributions, great or small, our products can make to a LEED project.”

Installing the last panels on The Warp glazing project in Surrey, British Columbia. Photo By Kamil Kropac, Courtesy Of Aluminum Curtainwall Systems.

A: Tony Menecola, owner and president, Applewood Glass and Mirror:
“It is just starting to appear in specifications, especially in Design Build. We have been involved on two relatively small LEED projects and are presently working on one that is a seven storey curtainwall. Most requirements thus far have been relatively easy to achieve because they have been more product oriented rather then design oriented but I’m sure that will change.”

Q:What role will ‘smart curtainwall’ technology play in the design and development of new curtainwall systems?

A:Kevin Fairchild, product marketing manager, Kawneer Company:
“I think we are on the front end of a shift towards ‘smart curtainwalls’. As photovoltaic panels become more powerful and less costly, we will see this market expand quickly. The same is true for double-skin and other ‘smart curtainwalls’. Once building owners feel that the ‘pay-back’ period for investing in self sustaining or smart curtainwalls is acceptable, the market will gravitate to this technology.”

A: Frank Luciani, president, Aluminum Curtainwall Systems:
“The ‘smart curtainwalls’, the ‘twin-wall’ systems, the façades incorporating photovoltaic elements within their designs will all play a major role toward achieving the ’zero energy’ building design goal. The ‘twin-wall’ system is a scientifically sound approach of designing a building façade, but surprisingly it has not been utilized enough in our country. With more emphasis on energy efficiency in buildings we feel that it is inevitable for ‘smart curtainwall technology’ to become the ‘new curtainwall standard’ in the future.”

A: Steve Gusterson, pre-construction design services, Alumicor Limited:
“The development of new systems is primarily driven by what designers demand. In turn, the designers
(architects) rely on their clients, the owners, to permit them some foresight in building design. Unfortunately, I don’t believe we have enough sophisticated end-users in Canada. For the most part, the market is driven purely by price which permits little or no creativity in design. Outside of universities, there are few owners that are willing to spend the money or take the risk of incorporating new or expensive technology into their curtainwall designs. LEED may help to change that thinking.”

A: Tony Menecola, owner and president, Applewood Glass and Mirror:
“We have found these products to be too costly and therefore owners/architects have typically changed their minds but if costs go down it would make them more attractive to end-users.”

Q: Where are trends heading in the future?

A:Kevin Fairchild, product marketing manager, Kawneer Company:
“I think we will begin to see more and more pre-glazed and unitized curtainwalls in the market. Thermal products will become more prevalent, even in warmer climates. We will see huge advancements in photovoltaic and other smart curtainwall technology.”

A: Frank Luciani, president, Aluminum Curtainwall Systems:
“Today the trend is in ‘design expression’, meaning complex building shapes incorporating the latest glass technologies that are currently available. In the future it will be more of the same with greater emphasis on energy efficiency and energy recovery.”

University of Toronto, Terrence Donnelly Centre for Cellular and Biomolecular Research, Toronto, Ontario, features a modified version of Kawneer 2500 PG Wall, unitized curtainwall. Photo Courtesy Of Kawneer Company.

A: Steve Gusterson, pre-construction design services, Alumicor Limited:
“Productivity, quality control and fewer hours spent on site will require we prepare for much more in pre-glazed and unitized product. The glazing contractors need to start considering the capital investments necessary to move in this direction.”

A: Tony Menecola, owner and president, Applewood Glass and Mirror:
“Higher performing walls incorporating triple glazed units with high performance thermal breaks. We have done a few and owners swear by the reduced utility costs. We have also seen an increase in translucent spandrel areas as well as a move away from the ‘mirrored’ reflective look on office buildings.” -end-

Who makes what?
Curtainwall products and systems manufactured for the North American market:

Kawneer Company: 1600 Wall System 1, 1600 Wall System 2, 1600 Wall System 3, 1600 Wall System 4, 1600 Wall System 5, 1600 SS (Screw Spline) Curtain Wall, 1600 L-R Wall, 7500 Wall, 2250 IG (Inside Glazed), 2500 L-R Wall and 2500 PG (Pre-Glaze) Wall.

Aluminum Curtainwall Systems (ACS): Specializes in the manufacture of unitized, pre-glazed curtainwall systems, based on the rain screen principle as well as passive solar control and day lighting devices such as sunshades and light shelves.

Alumicor Limited: 1750 Series (13⁄4 inch profile) stick curtain wall; 2200 Series (2.0 inch profile) stick curtain wall; 2500 Series (21⁄2 inch profile) stick/pre-glazed curtainwall; BF2000 (21⁄2 inch profile) unitized curtainwall.

Applewood Glass and Mirror: Unitized and stick systems – products from Fulton Windows, Kawneer and Alumicor. -end-