Category Archives: research

What does building performance “research” mean, exactly? (part 2)

The Scandinavian hospital study illustrates several contributions that building research offers, that energy modeling, commissioning, and system monitoring cannot:

1. Understanding of design intent

The vision of the design team – owners, stakeholders, architects, and engineers – has a permanent impact on the energy performance of a building. Siting, geometry, orientation, envelope materials, organization of the program, spatial configuration, and environmental control system choices all reflect this vision, tempered by constraints of time, money, and building codes, and all have substantial impacts on the energy needed to heat, cool, light, and ventilate the building.

The effects of these key performance-affecting decisions are so decisive, and so long-lasting, that we must understand the forces that shape them in the design process. This element is therefore a cornerstone of building performance research.

2. Systems-level analysis

Buildings operate as complex systems of people, machines, structures, and climates. Since these elements affect building performance as an interacting set, a clear understanding of building performance necessarily requires investigation into the operation of the system as a whole. Energy models do simulate buildings as systems, but their best role is to inform decisions among a limited set of design alternatives; they are definitely not diagnostic tools. To understand the operation, and especially the malfunction, of a real building requires field investigation.

Revealing unexpected activities of occupants, and understanding the origins of these activities, is an especially important aspect of field research. Unprogrammed use of spaces, manual overriding of system controls, and propping openings open or closed are just a few ways that occupants can unwittingly diminish the energy performance of their building; tracing these to their motivations, and then to concrete aspects of the building design or operation, is an essential component of systems-level building research.

3. Pattern discernment through comparison of multiple buildings of a type

Each building is substantially unique: despite common elements, a particular assembly of spaces, materials, climate, program, and occupants is rarely duplicated. This complicates efforts to determine which performance strategies work well, and which don’t, in a particular building type. Yet, as the Scandinavian hospital study shows, patterns do emerge when enough examples of a type are compared.

The seeking of patterns among multiple examples of complex systems has excellent precedents in field ecology (see work by E. Odum and J. Lovelock) and in architecture (C. Alexander, A Pattern Language). Their field techniques and analytical tools are directly applicable to building systems, as well, and should inspire us toward a “comparative building ecology” that illustrates performance patterns, in their contexts, robustly.

4. Controlled experimentation

Although every building is an uncontrolled experiment, some controlled experiments can be conducted within a building, nonetheless. Energy use of analogous spaces that differ only in occupancy or equipment can be compared; conditions in individual spaces can be tracked through varying seasons; passive airflow paths can be obstructed or cleared; light shelf sizes and angles can be varied; setpoints and schedules of mechanical systems can be adjusted, for example. While such adjustments are often undertaken by facilities managers, rarely are the results of individual changes tracked over time to yield meaningful information. Such experiments might also be simulated with models; an intriguing document by the New Buildings Institute presents such analysis for large buildings. Given the limitations of models, however, the realm of controlled experimentation remains an important one for teasing apart relationships among spaces, people, and environmental control systems in real buildings.

5. Publication

The ultimate goal of pure research is to publicize the results, so that a wide audience can learn from them (where “publication” includes meetings, talks, discussion forums, and websites as well as design and science journals). In contrast, commissioning reports and building energy models are private documents; indeed, building designers and owners are understandably reluctant to publish evidence of performance below expectations.

At the same time, the disclosure of design decision pathways, model predictions, operational realities, and performance outcomes would help future design teams immensely. This, therefore, is the most important of the unique contributions that building performance research has to offer: the provision of reliable information, obtained through rigorous investigation and experimentation, unbiased by financial or legal interests, in straightforward, accessible forms with the strength to change common practice.

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What does performance “research” mean, exactly? (part 1)

If “research” means original research, and if buildings are created from principles of spatial design, climate responsiveness, structural stability, heat transfer, fluid mechanics, and hydrophobicity, among others, that are already known, then what, exactly, does “research” mean in the context of the built environment? What else is new, in these constructions, that we have yet to learn? More specifically, what can we learn that is generally true, and generally applicable – that can inform the design of future buildings?

To an architect, there is still quite a lot! To a social scientist, there is an equal abundance. But in terms of energy performance…what can original research really offer, that energy modeling or commissioning or just system monitoring cannot?

One study that’s influencing our current work is still in progress by members of the University of Washington Integrated Design Lab in collaboration with BetterBricks and I-Sustain. Several additional people, including NBBJ architects and my boss, have also been closely involved. In this work, the group investigated a number of different Scandinavian hospitals, analyzed their geometry, orientation, layout, loads patterns, envelopes, hvac system design, and energy usage, and distilled a series of truths from the results that are evidently unknown to the US hospital design community. This will be a fantastic resource when it’s published!

One striking result, for example, was the superior effectiveness of decentralized ventilation systems in combination with radiant heating and cooling. While the inherent wastefulness of VAV reheat systems might seem obvious, with the strategy of cooling air to the lowest temperature needed by any of the zones served, and then reheating it locally for all the rest, the majority of American hospitals are designed with this exact system type. The next question, of course, is why? Are they cheaper? Easier to install? More reliable? Or just “the way it’s always been done”? There must be some obstacle out there to changing common practice.

(to be continued…)

Every building is an experiment

Scientists always replicate their experiments. No journal would publish their work if they didn’t.  Field ecologists agonize over finding comparable niches, hoping that statistical analysis will tease truth from the daunting variability of the natural environment. Chefs try a recipe repeatedly, adjusting ingredients minutely, to find the perfect taste. Athletes and musicians practice moves and passages over and over, striving for the subtle nuances that will make all the difference in the final performance.

But in architecture, every building is its own experiment. With rare exception, it is an experiment of one. No controls, no replicates, just one glorious culmination of years of hopes and ideas and struggles to get the thing built. And what of its performance?? Spatial performance is rewarded with glossy features in Architectural Record or Dwell. But “Star-chitects” like Peter Eisenman notwithstanding, energy performance is also a very real concern among designers! Buildings use enormous amounts of energy, and as a result, enormous effort has gone into programs to promote green building design: LEED, SEED, Architecture 2030, International Living Building Challenge, to name just a few. Buildings routinely win awards, gain certifications, and advertise themselves as “green” on the basis of design alone. Think of how astonishing this is: would a recipe, a music composition, a dance, a space, win awards without ever being experienced?

To be sure, building performance can be predicted to some extent from digital models. I build DOE2 and EnergyPlus models for a living, for example. They are valuable, even essential, tools. But they are not the whole story. Each model is only as good as the information that goes into it, and information is always incomplete in schematic design, which is when most building energy models are built. Elements get changed in design development without re-analysis. Decisions are re-visited during construction, materials are substituted, mistakes are made, budgets are cut, timelines are quickened, and occupants use the building in unexpected ways.

But what about that performance? Isn’t the final performance important enough that we actually go check, to see if the experiment worked? Actually – no! Tragically, most buildings never receive any greater performance assessment than the owner’s monthly glance at the utility bill. This is tragic because vast resources are invested in buildings, because thousands of green buildings have been built in the last decade and thousands more are on the boards, and because the lessons available from those we’ve built are not even being listened to, with a few laudable exceptions (such as those published here and here), so that new ones can benefit.

This blog exists for the green building agents who are out there listening, for public agencies that need persuasion to fund green building research, for new green buildings with valuable messages, and for designers who urgently need these messages.