Decisionmaking process

Here, we define an “integrated” façade as a façade that is designed, analyzed, procured and operated as a system. This is in contrast to a façade that is treated as building skin and is considered only as a layered configuration defined by its construction and its impact on the building as such. In the past, building façades have seldom been treated as integrated systems. Many factors have contributed to that; lack of full understanding how they function in buildings is only one. Building procurement constraints, difficulties in multi-party communication and collaboration, and conflicting participant interests are some of the other.

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 marshal, 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. For example, the architect may propose an integrated façade that poses additional requirements on the structural system design, which in turn may increase construction cost; the client may object to the higher cost and, in the attempt to reduce project cost, the value engineer may eventually eliminate the integrated system altogether.

Agreement among decision makers is harder to reach if their backgrounds and professional experience are heterogeneous. Integrated façades are typically very complex systems that require a high degree of technical understanding and consideration 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 one-sided performance, a malfunctioning system, or in the elimination of the idea.

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. Decision-making is much more difficult when it is done sequentially and with only selective information available. 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.

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. These are computer programs that can analyze 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 prolonged 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. Such tools can serve a dual purpose: (a) to predict the performance of components, integrated systems and the overall building, and (b) 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.

The following table is a partial list of commercial software available in North America that can be used in the planning, design, analysis and evaluation of integrated façade systems. Software in the figure is grouped by profession that uses the software as part of its regular work process. The figure does not include proprietary software that is in use exclusively by organizations that developed the software.

Table of commercial software tools

Note: This is a snapshot of existing tools. Others may not be mentioned here in this list.

Question/Information: eslee@lbl.gov