Informed Design: Lessons Learned

How Moseley Architects Uses Analysis to Leverage Design Creativity

Moseley Architects has been working since 2000 to continually improve the sustainability of its design portfolio. Over the past four years, the firm has placed a particular emphasis on integrating performance analysis into its early design process. John Nichols, Moseley’s Director of Energy Analytics and Informed Design, has led this effort since its inception, and recently sat down with us to share his insights. From massings to metrics and envelope to fenestration, here is an overview of Moseley’s modeling approach along with four important lessons the firm has learned along the way.

Moseley’s “Informed Design” Initiative

The intent of the Informed Design initiative is to combine the power of analysis with the creativity of design teams to improve building performance across Moseley’s diverse project portfolio. According to John, the name Informed Design “speaks to our goal of making decisions in response to modeling data in a way that leverages our designers’ inherent creativity, without being limited or boxed in by numbers alone.”

A secondary goal of the initiative was to improve the firm’s AIA 2030 Commitment performance. “We were struggling with the 2030 Commitment in the sense that it’s like a GPS signal without navigation,” says John. “It shows us where we are versus where we want to be, but it lacks any turn-by-turn guidance to help get us from A to B. We needed a process that could help bridge that gap.”

The result was a lightweight, collaborative workflow for schematic analysis that capitalizes on performance data from Sefaira’s analysis plugin and web application. After an initial pilot phase that involved an architect from each of Moseley’s offices and market sectors, John worked to expand the process firm-wide.

To date, Moseley Architects has implemented Sefaira analysis on over 50 projects and 20 interviews across five different market sectors. Here are four key takeaways from the firm’s experience thus far.

1. Massing-Stage Analysis is Key to Informing Design

Moseley’s experience reaffirms the importance of massing decisions, particularly on daylighting and HVAC loads. John’s experience has also been that the visibility of data at this stage focuses priorities and helps to stimulate discussion about performance between the client and design team.

Massing analysis showing breakdown of energy end uses and annual daylight metrics. Image copyright Moseley Architects, used with permission.

As shown above, even a simple massing comparison inevitably raises questions. “Why is the cooling load in the plaza option so high? Why is the daylight performance of the Courtyard scheme worse than the L option?” These types of questions lead to conversation, follow-up analyses, and often to design changes. For example, reworking the “plaza” massing in this example significantly improved its performance, while a daylight visualization of the “courtyard” and “L” schemes clarified the advantages of the latter.

Reworking the “Plaza” option in response to the original analysis data greatly improved its energy and daylight performance. Image copyright Moseley Architects, used with permission.

“Just having this type of discussion before the floor plan and massing have been ‘nailed down’ is a big step forward,” says John — and often leads to improvements that would not have otherwise materialized.

A daylight study shows the advantages of an L scheme over the option with a small courtyard. Image copyright Moseley Architects, used with permission.

2. EUI Isn’t Always the Best Metric

Many design teams and clients are readily familiar with Energy Use Intensity (EUI), and projects may even have specific EUI targets. But while EUI is an important point of comparison, it doesn’t tell the whole story. In particular, John’s experience is that:

EUI doesn’t always align with energy cost, or with carbon emissions, which may be more important goals on many projects; and
EUI can mask differences in total energy use and cost, which are often caused by differences in square footage between options.

The key take-away from these analyses, according to John, is that looking at cost, carbon, comfort, and peak loads can reveal problems or opportunities that may otherwise go unnoticed when EUI is used as the sole metric.

Project B has a slightly lower EUI than Project A, but significantly higher energy costs and carbon emissions. Such discrepancies are often due to the different costs and carbon intensities of on-site natural gas vs. electric heating in areas with a coal-dominated electric grid. Image copyright Moseley Architects, used with permission.

A more efficient layout with less circulation and support space (i.e. higher Building Efficiency Ratio) can result in real savings in upfront capital costs and ongoing energy costs, even if the resulting EUI is slightly higher.

3. The Envelope Matters — Even on Large, Internally-Loaded Buildings

Conventional wisdom holds that big buildings are “internally loaded” — dominated by loads like lighting, appliances, and ventilation — and therefore the envelope is less important than on small buildings.

Energy consumption tends to be dominated by external loads in small buildings, and by internal loads in large buildings. But this doesn’t tell the whole story. Image copyright Moseley Architects, used with permission.

While Moseley’s modeling experience bears this out when looking at overall energy use, John has also seen that the envelope still matters when viewed on a space-by-space level. Visual comfort, thermal comfort (particularly in spaces with lots of glazing), and peak heating and cooling loads can all be significantly impacted by the envelope (Image 8), which may not be apparent if the analysis focuses only on the building’s energy use. According to John, early decisions that reduce peak loads can result in smaller, less expensive HVAC system, which is a valuable addition to their ongoing annual energy savings.

Glazing orientation has a big impact on daylight quality and solar heat gain, as seen here for a pair of classrooms with a shared corridor. Even on projects where the overall building orientation is driven by site or other constraints, the orientation of key program spaces can greatly affect both comfort and HVAC loads.

4. Glazing Decisions are too Complex to be Made by Rules of Thumb

Glazing size, glass properties, and shading devices need to be studied together in order to make optimal glazing decisions. In the example below, a study of clerestory windows in a gymnasium demonstrated that glass with higher visible light transmittance allows the glazed area to be significantly smaller, enabling the project to achieve the same daylight levels with less construction cost and better energy performance — a finding that would have been missed if the glazing was selected primary based on its Solar Heat Gain Coefficient. Similarly, a comparison of different toplighting options for a fire station revealed that several small unit skylights were the most effective solution for both energy and daylight — which ran contrary to the team’s initial expectation.

Glass with higher Visible Light Transmittance (VLT) can sometimes achieve the same daylighting results with a smaller glazed area, as proved to be the case for the gymnasium clerestory windows shown here.

Conclusion

In addition to these and many other lessons-learned, Moseley Architects has seen early-phase analysis lead to a number of improvements to the firm’s design process and project outcomes. Since launching the Informed Design workflow, Moseley Architects’ use of energy modeling as a design tool has increased from less than 40% of projects to now more than 60%. While less quantifiable, John also sees positive impacts on team collaboration, client relationships, and internal knowledge around performance. Moseley Architects’ experience shows that fast, lightweight analysis can be deployed effectively across a firm, can have a meaningful impact on performance outcomes, and can add real value to projects.

About Sefaira

Sefaira’s Software-as-a-Service (SaaS) solution enables architects, building engineers, and designers to create more energy-efficient and comfortable spaces. By using Sefaira, practitioners can reduce energy use while optimizing for better occupant comfort, effective natural daylighting, and appropriately-sized heating, ventilation and air conditioning (HVAC) systems. Learn more at www.sefaira.com