ARTICLE BACK TO ZERO
PASSIVE HOUSE
THE OBSTACLES OF EXCEEDING EXPECTATION
In the January issue of Connection, I wrote about the Passive House -- covering the technological means and methods by which this new level of sustainable craft may be achieved. I wish that I could say that the process since that time has been a seamless one, but the future of sustainable design is sometimes a harder reality to achieve in the present. Given that passive design is not yet a wholly recognized practice, I'd like to take this opportunity to address the potential roadblocks in pursuing a level of design that exceeds standard energy codes and the difficulties of getting “Back to Zero�.
I now have two projects that are designed to approach Net-Zero Energy consumption, but taking theoretical drawings and models into reality has been anything but simple and straightforward. Both projects are in construction as of this publication, but energy detailing, construction budgeting, and client compromises have led to long delays from both original schedules. I had hoped to have a great many pictures from the various stages of construction from January to now, but I have to apologize to you, the reader, that not much has transpired on site, except for the hope that we will not give up and maintain optimism for the completion of each project by early spring 2015. The Phoenix House that had been featured in the January issue of Connection has, in fact, received Passive House Institute US PHIUS+ Pre-Certification; allowing us to proceed with construction in confidence that the performance criteria are met in the design. Over the past ten months, however, construction has been limited to foundation and basement work, and the installation of the prefabricated exterior shell panels. The on-site delay experienced by the contractor, in this case, was due to the proprietary panels, the fact that this integral product could only be sourced in Germany, and that Germany had been plagued by recent dock strikes. Of course, a worker strike could happen anywhere. The unfortunate aspect of this lesson, however, is that Passive House approved products are difficult to source in the States; not only taxing projects (our clients and contractors) with international freight, but with longer lead times in the procurement of products that are necessary to achieving highperformance standards. In the end, the panels arrived a whopping eight-weeks after the expected delivery date. And it was only after the panels were in-
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hand and installation begun, that the contractor noticed additional complications: first, in not having the required number of panels and second, that a number of the received panels would require refabrication as they were not to specification. In both cases, the issues had been caused by mistranslation of the shop drawings into fabrication of the panel system; resulting in newly and refabricated panels that again required transatlantic shipping and further delaying construction. Prefabricated construction promotes a variety of benefits; not the least of which is precision fabrication and ease of assembly through the controlled environment of skilled craftsman in a factory setting. The final on-site assembly, on the other hand, remains a challenge for framing crews (particularly those in the US) that are largely unfamiliar with the process and craft of constructing prefabricated structures. Presenting these few lessons-learned is in no way meant to discourage architects, clients, and builders from pursuing NetZero projects. On the contrary, reducing the carbon footprint of our built environment is a necessary part of creating sustainable communities. It is by sharing our lessons learned that we can avoid future such pitfalls and, hopefully together, create an industry in the US that is conducive to developing high-performance projects. One common dilemma of any project -- that could have led to fewer problems on the Phoenix Passive House -- is more transparent communication. There was a point in the contract documents phase for instance, when the bid process was completed, that our client came to terms with costs that were not anticipated due to the premium placed on high performance building products and systems. There has been a breakdown in communicating both the value and the premium associated with such projects.
THE ARCHITECTURE AND DESIGN JOURNAL OF THE YOUNG ARCHITECTS FORUM