BUILDING ENERGY USE
Buildings account for 33% of Seattle's core greenhouse gas emissions. Seattle's Energy Benchmarking Program requires owners of non-residential and multifamily buildings (20,000 square feet or larger) to track energy performance and annually report to the City of Seattle. From combing through the 2018 dataset, 3,491 buildings reported on their energy use. Highlighted below are interesting insights in Seattle's building history from the data. The Office of Sustainability has produced multiple reports on this data as well, available here.
Building Type and Year Built Within the data, buildings are broken out into seven different categories and have data on year built. See the graph below to see number of buildings built per year by building type. Some interesting items to note:
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Building Height and Year Built
When it was completed in 1912, the Smith tower (38 floors in height) was the tallest building west of the Mississippi. The next building built in Seattle over 40 floors wasn’t built until 1969 (Westin Hotel), 57 years later (we are excluding the Space Needle in this summary). Though it may seem from looking at downtown that we’re constantly building high-rises, buildings in Seattle are typically not high-rises: within the full dataset of 3,491 buildings, about 90% of them are six stories or less, with four stories being the most frequent building height. Buildings above 20 stories are all found in downtown Seattle and First Hill, except for three outliers: two in U-district (University Tower Plaza and UW Tower Building Complex) and one on Lake Washington in Madison Park (Washington Park Towers). These were all built before 1975 and would not be permitted under current zoning codes.
When it was completed in 1912, the Smith tower (38 floors in height) was the tallest building west of the Mississippi. The next building built in Seattle over 40 floors wasn’t built until 1969 (Westin Hotel), 57 years later (we are excluding the Space Needle in this summary). Though it may seem from looking at downtown that we’re constantly building high-rises, buildings in Seattle are typically not high-rises: within the full dataset of 3,491 buildings, about 90% of them are six stories or less, with four stories being the most frequent building height. Buildings above 20 stories are all found in downtown Seattle and First Hill, except for three outliers: two in U-district (University Tower Plaza and UW Tower Building Complex) and one on Lake Washington in Madison Park (Washington Park Towers). These were all built before 1975 and would not be permitted under current zoning codes.
Energy Efficiency by Building Type
Energy use greatly varies by building type. Scroll through the list below to see the average energy use intensity of the 59 building types. Data centers come in as the most energy intensive, using over 50 times the energy per square foot as a self-storage facility.
Energy use greatly varies by building type. Scroll through the list below to see the average energy use intensity of the 59 building types. Data centers come in as the most energy intensive, using over 50 times the energy per square foot as a self-storage facility.
Multifamily Housing Energy Use Efficiency
Has multifamily housing gotten more energy efficient? Yes, it has. Plotting out the energy use efficiency per square foot of multifamily low-rise (1 to 4 stories), mid-rise (6 to 10 stories) and high-rise (over 10 stories) and their associated trendlines, we see a continued decrease in energy use per square foot for all three multifamily building types. This is to be expected as the data covers a 118-year period and technological improvements in building materials coupled with more aggressive energy efficiency goals has led to this improvement.
Has multifamily housing gotten more energy efficient? Yes, it has. Plotting out the energy use efficiency per square foot of multifamily low-rise (1 to 4 stories), mid-rise (6 to 10 stories) and high-rise (over 10 stories) and their associated trendlines, we see a continued decrease in energy use per square foot for all three multifamily building types. This is to be expected as the data covers a 118-year period and technological improvements in building materials coupled with more aggressive energy efficiency goals has led to this improvement.
Grocery Store Energy Efficiency
Let's look at energy use at grocery stores in more detail, the sixth most energy consuming building type per square foot. The dataset has energy use data for 38 grocery stores. There are many factors that affect the energy use of a grocery store per square foot, with key drivers being the energy efficiency and size of the building, how much of the store is refrigerated/frozen/prepared food versus dry goods, if the building is standalone or part of a larger complex. Is there any correlation between the age of the building an energy use intensity? Not really, it seems to be more tied to other factors.
Let's look at energy use at grocery stores in more detail, the sixth most energy consuming building type per square foot. The dataset has energy use data for 38 grocery stores. There are many factors that affect the energy use of a grocery store per square foot, with key drivers being the energy efficiency and size of the building, how much of the store is refrigerated/frozen/prepared food versus dry goods, if the building is standalone or part of a larger complex. Is there any correlation between the age of the building an energy use intensity? Not really, it seems to be more tied to other factors.
Conclusion
Energy efficiency of buildings is a complicated, as many factors affect it: building age, size, primary use type, geographic location, building occupancy rates, and annual weather changes. That said, analysis of data can shed light on how specific buildings are functioning to comparable ones. Once the 2020 data is released, it will make for an interesting comparison to see how building energy use has changed by type as a result of the COVID-19 pandemic.
Energy efficiency of buildings is a complicated, as many factors affect it: building age, size, primary use type, geographic location, building occupancy rates, and annual weather changes. That said, analysis of data can shed light on how specific buildings are functioning to comparable ones. Once the 2020 data is released, it will make for an interesting comparison to see how building energy use has changed by type as a result of the COVID-19 pandemic.