The Most Powerful Tools

“Si quaeris peninsulam amoenam circumspice” translates to “If you seek a pleasant peninsula, look around you,” is the official motto of the state of Michigan. This motto, which appears on the state’s flag and seal, was adapted from Architect Christopher Wren’s inscription in London’s St Paul’s Cathedral, stating, “If you seek his monument, look around you.” In both cases, the message is the same. At some point along the journey, it’s good to recognize that you’ve arrived. Often, it will be sooner than you might expect. 

During my time consulting with architects on sustainable design, the questions I receive most often are about tools. Architects ask which simulation tools they should use to evaluate a design, where to find lists of all available tools on a given topic, or which tools are new and exciting. Along with locating and evaluating tools, I’m also asked to review new tools and to help develop specific tools that don’t yet exist. Typically, my response to any question about tools is my motto for sustainability in architecture, “If you seek the knowledge to design a sustainable building, look around you.”

Architects are trained in passive strategies from the first year in architecture school. Most have read books such as Sun, Wind, and Light or Design with Nature and typically have a good intuition for the strategies that lead to great daylight or energy performance. Even if the phrase “passive strategies” or “environmental design”  was not explicitly used to describe a building’s relationship with its site and climate, architects tend to understand whether or not the sun is desirable in a specific space at a particular time of day. More often than not, the answers to the questions that would be addressed through simulation tools are relatively straightforward to the confident, trained professional. Confidence is the key in that statement since it’s often a lack of confidence that creates the need to hide behind computer-generated numbers rather than rely on one’s own professional intuition. Luckily, confidence can be built through practice. One of the best ways to build good intuition, develop confidence, and improve project performance is by stepping back and looking at a project with a critical eye.

The formal process for using existing knowledge and mindfulness to evaluate a design is called Critical Analysis, and it’s an effective alternative to simulation tools for early concept work. To perform a critical analysis, begin by setting aside a time to analyze a design, maybe an hour at an early milestone, and invite others to engage, both those involved with the project, as well as fresh eyes. Intentional and mindful separation from the busy everyday workflow is critical, so keep the block of time firm and unrushed. Start the conversation by familiarizing the group with the project and its performance goals and then taking five minutes or so for everyone to think through the design, its strategies, constraints, opportunities, early success, and potential problem areas on their own in silence. For the remainder of the session, evaluate the project’s approach to realizing the goals one by one, by comparing its design strategies against accepted best practices and established rules of thumb. Be sure to end up with a plan for changes or strategies that would improve the project’s performance relative to its goals.

It might seem like I’m describing a design review or project pin-up, which is precisely correct. When we discuss design during a pin-up, we compare the project before us to our knowledge of design and identify strategies for improvement. We don’t need to first run the project through a “design quality” computer simulator. We, as architects, have confidence in our ability to discuss design and steer a project in the right direction. The difference with a critical analysis is the topic of discussion; it’s about performance rather than aesthetics. The discussion must focus on the project’s goals and the architectural strategies necessary to realize those goals.   

Here’s an example to help demonstrate the process. Suppose that a project in a hot, humid climate has a goal of meeting the 2030 challenge and must achieve a EUI of 20 kBtu/sf/y for an 80% reduction from the benchmark of 100 kBtu/sf/yr. The current design contains large expenses of west-facing glass and a thin roof construction. Established best practices for energy conservation for that climate and building type include limited glazing, extensive shading on the Western facade, and sufficient insulation in the walls and roof. The first takeaway should be that the project is not on track to achieve its goal due to the heat gain from both radiation through the windows and conduction through the roof. Strategies for improvement might include limiting western glazing below 40%, shading the western facade, and ensuring enough space in the roof for quality insulation. At this point, the project team returns to their desks and incorporates strategies that will improve the building’s energy performance. It wasn’t necessary to know numerically how the design performed to understand that it was not on track to meet its goal or how it could improve. Seems simple?

“If you seek the knowledge to design a sustainable building, look around you.”

There are a few reasons why the critical analysis works as well as it does. First off, it’s fast. You can typically have actionable results in an hour or less with a small group or even in just a few minutes if completed solo. This is analysis at the pace of early design. Sending off a concept model for energy simulation and waiting a week for feedback is ten thousand years in concept-design-time. Running a simulation in-house might require more time just to fire up the software. If the modeling tool is too simple or if the modeler doesn’t have sufficient experience, the result is unlikely to be useful, regardless of how many digits follow the decimal point. Second, it’s free. In-house energy modeling tools often require expensive subscriptions, which can be onerous for smaller firms. Sending off a model to an outside consultant will eat up fee that could be better spent digging into details on later phases. Critical analysis requires nothing but existing knowledge and a bit of mindfulness. Last and most significantly, the architectural factors that determine building performance are not all that elastic. They’re also not mysteries. Windows can’t supply daylight to a distance beyond 2.5 times their height, so deep floor plates will be underlit. Buildings with a lot of glass use a lot of energy and are less comfortable every time. A sensitivity analysis will show that an architect has limited ability to improve energy performance but a lot of ability to throw open the energy flood gates. Projects that follow the best practices will perform well, while projects that stray from the established rules of thumb will not.   

After working through critical analysis, a project should be around 85% of the way there - no major mistakes, but not exactly optimized. For many projects, this is a fine place to end. Further analysis with simulation tools might not be necessary. For other projects, building performance simulation tools can be used to fine-tune a project from 85% to 99%. It’s best to begin engaging with modeling tools after opportunities for additional value from critical analysis have been exhausted. This usually means mid-schematic design for daylight modeling and design development for energy modeling. At these phases, the massing is less fluid, systems are being discussed, and schedules, occupancy, and specifications are a bit clearer. A computer simulation will now have enough information to produce meaningful results, and waiting a few days for a thorough result will still produce actionable information. 

An exception to the general critical-analysis-before-moving-to-simulation-workflow is when conditions are so complicated that good intuition cannot be effectively applied. For example, this might be the case with adaptive reuse, an odd orientation, an unusual program, or some other reason that the typical rules would not apply to a particular project. In this case, and only in this case, should a project skip critical analysis and engage directly with simulation during concept or early schematic design. 

Developing a good professional intuition is essential to creating sustainable architecture and leveraging this intuition with the right tools will allow any project to perform to its potential. Now, to return to the original question about which tools to use. There are many design tools out there, and more are being developed all the time. I like to group design tools into three categories based on their application and effectiveness to keep things simple. The three groups are tools that should be used on all projects, tools that can provide value on some projects, and ineffective tools that should not be used at all.

The first category, tools that should be used on every project, includes benchmarking and climate analysis tools to provide the contextual information necessary for goal setting and critical analysis. Also in the group are tools that provide best practices and rules-of-thumb to help develop intuition.

The second category, tools that can add value to some projects, comprises simulation tools. This group includes energy modeling, daylight modeling, computational fluid dynamics, life cycle analysis, and the like. This category is the broadest of the three and has a lot of variation within it. Based on the ratio of time required to gain actionable information, some types of simulation should be used more frequently than others. For example, daylight and glazing radiation simulation can be used on almost every project, while energy modeling and life cycle analysis can be performed more sparingly. Finally, any simulation involving airflow should be deployed only for unique, targeted cases. As a rule, simulations should always be performed by trained professionals. Without the necessary experience, It’s too easy to generate incorrect data or misinterpret results, which doesn’t help to improve the design.

The third and final category is for the tools that should not be used. This category is made up of simulation tools simplified down to be accessible to an untrained audience. Building performance simulation is complicated, and the simplification process limits its effectiveness. In the end, there’s no free lunch. General audience simulation tools typically can’t provide any more value than a critical analysis, and those with experience would choose more technical tools. 

In the end, the question of what tools to use comes down to first understanding where you want to go and then choosing the simplest method for getting there. Here’s another quote, this one by Henry David Thoreau, which is good to keep in mind when thinking through the potential of tools to improve project performance.

“Men have become the tools of their tools. Money is not required to buy one necessity of the soul. Most of the luxuries and many of the so-called comforts of life are not only not indispensable, but positive hindrances to the elevation of mankind.” 

Basically, Thoreau is saying, “if you seek a tool to improve your design, look around you”.