Unitized Curtain Wall

Case Studies in Performance Optimization and Design Variation

Overview

Authors

Photo of Brian Masuda

Brian Masuda

Ennead Architects

bmasuda@ennead.com

Photo of Kathleen Kulpa

Kathleen Kulpa

Architect

Ennead Architects

kkulpa@ennead.com

Photo of Margaret Tyrpa

Margaret Tyrpa

Ennead Architects

mtyrpa@ennead.com


Keywords


Abstract

Unitized curtain wall has become ubiquitous in contemporary facade design and construction due to advantages associated with speed of erection, lower installation cost and improved quality control. The degree to which these benefits are realized is directly proportional to the ability of the designer to maximize repetitive detailing and minimize the number of unit types. These two factors often contribute to design solutions that are characterized by a uniform appearance.

With the ever-increasing performance requirements of building facades, the ability for unitized curtain wall systems to transcend their innate uniformity by accommodating variability in configuration and material infill is becoming compulsory. There is an increasing need for exterior wall systems that can accommodate variation within an efficient framework in order to respond to unique and specific environmental, programmatic and aesthetic parameters.

The David H. Koch Cancer Center Memorial Sloan Kettering in New York City and The Beus Center for Law and Society in Phoenix, Arizona are two case studies that explore the potential variability in unitized wall systems as a way to optimize performance. Key points to be covered include: designing flexibility into the module to create a more adaptable response to specific solar conditions, context, program, and aesthetic considerations; the integration of opaque infill panels into a unitized wall system adopting properties of a rainscreen to optimize thermal values; and the ability of a unitized wall system to support self-shading geometry and depth as a strategy to control solar heat gain without additional layers which often result in thermal bridging. The similarities and differences between the two facades designs as a response to their distinct climates will be highlighted for each of the above topics.

Introduction

When first introduced, unitized curtain wall systems were mainly reserved for large scale urban buildings with great expanses of repetitive glass and metal facades. Projects with these characteristics were able

Access Restricted

Members get unlimited access to all of our resources. Join now for the best value.

Background

MSK + CUNY

The MSK+CUNY project, located on the Upper East Side of New York City, was a joint venture between two institutions, Memorial Sloan Kettering Cancer Center and The City

Access Restricted

Members get unlimited access to all of our resources. Join now for the best value.

Beus Center for Law & Society

The Beus Center for Law and Society (BCLS), the new home to the Sandra Day O’Connor College of Law at Arizona State University, is a six-story, 280,000-square-foot building located at

Access Restricted

Members get unlimited access to all of our resources. Join now for the best value.

Analysis & Response

MSK + CUNY

Figure 3: MSK + CUNY exterior wall rendering. Image courtesy of Ennead Architects.

The development of an exterior skin that satisfied both buildings had inherent design challenges. The two

Access Restricted

Members get unlimited access to all of our resources. Join now for the best value.

Geometry and Solar Control

The MSK client specifically requested maximizing the views for the patients receiving treatment, ideally vision glazing which did not require exterior or interior shading devices, even during peak hours of

Access Restricted

Members get unlimited access to all of our resources. Join now for the best value.

Integration of Opaque Walls & Thermal Performance

The design team evaluated material options for the opaque portions of the unitized curtain wall and chose terra cotta for its design properties and opportunities and for texture and depth

Access Restricted

Members get unlimited access to all of our resources. Join now for the best value.

Analysis & Response

Beus Center for Law & Society

Figure 9a: BCLS exterior sandstone and glass façade. Image courtesy of Ennead Architects. Figure 9b: BCLS outward-facing unitized façade location. Diagram courtesy of Ennead Architects.

Sited

Access Restricted

Members get unlimited access to all of our resources. Join now for the best value.

Stacking & Modulation

During the design process, digital tools were used to analyze a range of solar-related issues including building configuration, facade orientation, glare and daylighting, shading, and heat gain. This analysis informed

Access Restricted

Members get unlimited access to all of our resources. Join now for the best value.

Geometry & Solar Control

Vertical, strip glazing units at various widths were captured between sandstone-clad spandrel panels in a saw-toothed configuration achieving self-shading through window recess with an extended jamb return. A projection of

Access Restricted

Members get unlimited access to all of our resources. Join now for the best value.

Integration of Opaque Walls & Thermal Performance

Parametric studies were used to evaluate different patterns and rhythms of the modular array to calibrate window-to-wall ratios in order to keep internal cooling loads within specific low targets. Lower

Access Restricted

Members get unlimited access to all of our resources. Join now for the best value.

Detail Development

MSK + CUNY

The MSK+CUNY curtain wall design was based on the principals of unitized system; split vertical mullions, continuous gutters at the stack joint, and a continuous air barrier

Access Restricted

Members get unlimited access to all of our resources. Join now for the best value.

Detail Development

Beus Center for Law & Society

The opaque portions of the BCLS’s unitized wall system were developed as a spandrel back pan assembly and rainscreen stone panel system utilizing

Access Restricted

Members get unlimited access to all of our resources. Join now for the best value.

Conclusions

Unitizing curtainwall meets many of the demands of the current building industry: factory quality construction and a fast and cost-effective installation. Traditional unitized wall systems would benefit from improved overall

Access Restricted

Members get unlimited access to all of our resources. Join now for the best value.