This post was written by guest blogger Stephen F Pope, OAA, FRAIC of S.F. Pope Sustainability Consulting. Stephen has extensive experience working in Design Charrettes and has recently been working with Arborus in delivering Design Charrettes for Enbridge Gas Distribution’s Savings By Design green building initiative.
One of the challenges encountered in Design Charrettes is creating an environment where the design team can sufficiently distance themselves from “real life” in order to free up fresh and effective thinking. One circumstance that frustrates effective thinking is where the participating “designers” are not the project authors, rather they are staff charged with developing an established design. This results in an inability to critically discuss potential changes to “the design” and the resulting discussion of energy use isn’t as wide ranging as needed. The “designers of record” can be left defending an undeveloped position rather than looking at the whole picture with fresh eyes. For a design process whose highest aspiration is to find ways to increase energy efficiency AND save construction capital, this kind of restriction is very problematic.
To overcome the natural instinct to be defensive about prior decisions, one needs to establish a method to investigate the project assumptions at the early stages of the discussion. The setup is critical to preparing the soil for a fertile Charrette. One may want to open the discussion of a project with a comment such as:
“OK, for the purpose of this discussion, we are looking back at the project from some time in the future. The project is a tremendous commercial and financial success, and we wish to be clear about how and why. What were the conditions that made this project such a success? What are the user/owner/operator experiences that made that success?”
This is similar, but not as obvious as an “In an ideal world…” type of starting point, but the difference is important because sometimes it seems the building industry has lost its ability to think beyond the confines of the initial project assumptions. Talking about “an ideal world” can seem irresponsible to busy designers, leading them to think that the process is only fluff. Getting “practical” people to shed their preconceptions and received wisdom is hard work. It’s probably why Amory Lovins has been saying the same things for almost 40 years.
One use of the “discussing success” approach is to develop metrics for success that are outside of common parlance. Another reason is to smoke out any conflicting ideas about success and get them resolved as early as possible.
This approach can avoid the traps in the common design process by setting the context for the level of performance desired, rather simply stating a target. Conscientious designers take targets seriously, but tend to stop once that target has been achieved. Aiming at 25% better than code might actually be too low a target. Expressing the performance target as a change in the internal relationships between building systems may provide a more coherent description of success. For example, asking what level of improvement over code is required for the building envelope to produce a step-change in the mechanical plant and distribution capacity is a more tangible than asking for a 50% reduction in heat loss. The rephrasing of the performance goal identifies both improved performance capacities and potential savings that can be used to balance an increase in investment in the building envelope.
We also need to emphasize that changes to one system are important only with regard to the performance of the whole building. Talking about making the envelope “25% better” than code is misleading and technically incorrect. It may even be impossible to squeeze that much more out of the OBC 2012 SB-10 envelope requirements.
It is also important to distinguish between the “blue-sky” modelling undertaken during a Charrette and compliance modelling. Often consultants only imagine compliance modelling, and are stuck on the idea of the “accuracy” of the model rather than use of a model to get coordinated performance results across all building systems. In this respect we have to rescue energy modelling from the commodity service, compliance-based hole that it’s been thrown into. We have to encourage play.
One way to separate compliance from “blue sky” is to hold off the discussion of assemblies until a specific U-value for the specific project has been identified. This would tie into a set of questions promoted by the NREL Charrette Guide, where the modeller starts with generating the impacts of adiabatic envelop assemblies, then works backward to code levels, effectively making a description of the diminishing returns curve for the unique project.
At the beginning of the energy discussion in a Charrette, the designers are presented with modeling results showing the “best bets” or biggest hits in energy efficiency measures, and then asked to comment on the impacts and assemble the bundles of efficiency measures with which they would be most comfortable. This can be more effective in terms of engaging the designers than leading them blindly through the question of “What do we get if we do this?”. There may be a variety of different bundles that achieve a similar energy performance level and addressing the availability of different approaches makes it easier to find one where the effort and expense are seen to be worthwhile.
While this may require additional energy modeling prior to the actual Charrette, with this early investment it may be possible to encourage design teams to go well beyond the meeting a arbitrary performance target in search of the “tunnel through the cost barrier”.