Environmental Analysis Work Samples Project: biblio-ITHACA Victoria Lee
contents 00 Project Introduction, Documentation + Notes 01 Climate Analysis + Predictions 02 Solar Access 03 Renewable Energy Potential 04 Building Energy Model (BEM) 05 Detailing 06 Daylight Exposure + Visual Comfort 07 Conclusion
00 Project Documentation + Notes
Project title: biblio-ITHCA Address: 401-503 E State Street Project description: Situated on a site with unique landscape leveling, between a partial segment of the Six Mile Creek and E State Street, the library is a middle host that connects the nature and urbanscape of Ithaca. The library features layers of stone “screens” that invite its visitors from the busy urbanscape to a staged gradual reveal of the beautiful natural landscape of Six Mile Creek. The gradient of these layers of “screens” begin with stone blocks of strong presence, to stone stacking with gaps of filtered light, and finally opens to pockets of windows between a stone column grid that frames an unobstructed view of Six Mile Creek. Built flat ground up from a sunk-in site level, the library elevates itself to the E State Street level in a “staircase” formation. The “treads” of the “staircase” contains the programs of the library, and its hollowed space underneath serves as a parking structure for its visitors. The “treads” translate into a set of programmatic organizational bars that has a private-to-public program gradient from north to south of the library—the most private bar houses the visitor-restricted administration program and the room-bounded auditorium, and the most public bar houses the seating area with an open floor plan and large glazing that creates a sense of transparency for the space. With its unique gradient-layered arrangment and materiality, the library is intended to be a unique visual experience that highlights the contrast between the present-day artificiality in building quality—as shown beyond the stone material in the library and its surrounding context—and the authentic natural peace in monolithic architecture.
The front glass facade of the l
Elevation (south view) library reveals the layers of stone stacking and blocks in the library interior. The stone presence and elegance sharply contrasts the rest of the artificial building elements of the library and the surrounding architecture.
The library is set on a site w
Section (east view) with variations of levels, from a high elevation point on E State Street, to the sunk-in library site level, to the creek on an even lower level, and on a high elevation point again on the other side of the creek.
Setbacks / Buildable area Site Boundry: ~110 ft x 310 ft Site Area: 32,250 sq.ft
Buildable envelope isometric Max Buildable Area: 21,800 sq.ft 50% Lot Coverage: 16,125 sq.ft
01 Climate Analysis + Predictions
ITHACA, NY Geographical Information Location: 42.49°N, 76.47°W; Finger Lakes Region, Central NY; Northeastern U.S. Köppen Climate Classification type: Dfb General season conditions: warm and humid summers, cold and snowy winters Sun Path Between seasons, there is a significant difference in daylight hours in Ithaca. During the summer solstice (Jun 21), the daylight hours are 15 hours; meanwhile during the winter solstice (Dec 21), the daylight hours are 9 hours. The sun’s altitudes also vary greatly, where it sits at a higher altitude of 70° at noon during summer solstice and ~25° at noon during winter solstice. Wind rose Stronger winds are mainly coming from the northwestern and southeastern directions. They usually reach the levels of Fresh Breeze (8.0 m/s) and Strong Breeze (10.8 m/s). Diurnal averages The average temperature goes as high as 25° in the summer and as low as -20° in the winter. There is a larger difference between dry bulb and wet bulb temperatures during the summer, which means that there is a higher humidity over the summer. Solar radiation levels are also higher over the summer. Hourly heatmap: UTCI + Dry Bulb Temp. Similarly to the diurnal averages chart, the UTCI and dry bulb temperature charts lead to the conclusion that Ithaca has warm and humid summers. The UTCI further indicates that over the summer in Ithaca, there are 2889 days that have “No Thermal Stress” and over the winter, there are 2126 days with “Moderate Cold Stress”. The UTCI also helps visualize the length of the summer and winter seasons where summers are around May to August and winters are around late November to early April.
POTENTIAL DESIGN STRATEGIES SUNLIGHT EXPOSURE According to the sun path diagrams, it is evident that there is long sunlight exposure in the south direction of Ithaca. The southern facade needs to be protected according to the difference in sun altitude between the summer and winter.
Light shelves can be installed and they can protect the facade from direct, strong sunlight (solar radiation).
This sketch depicts a house model developed by Socrates. The strategy protects the building from strong sunlight (solar radiation) exposure during the summer, but allows more sunlight to enter the space during the winter. This is designed with the consideration of the difference in sun altitudes throughout the seasons.
SOLAR RADIATION + POWER Ithaca receives a lot of daylight exposure over the summer months, and the solar radiation from that exposure can be converted into energy use.
Solar panels can be installed to receive direct solar radiation and convert it into electricity use.
WINDPROOF The shape of a structure can help it become windproof.
A hip roof is ideal to combat against strong wind breeze, because its surfaces can direct wind to travel elsewhere instead of allowing the wind to hit the facade directly.
FUTURE WEATHER + CLIMATE CHANGE
Comparing the UTCI from 2020, 2050 and 2080, the data leads to the conclusion that there will be an increase in th 2080. There is also a decrease in “Strong Cold Stress” days from 1284 days in 2020 to 994 days by 2080. From the d To design sustainable structures with the consideration of future climate change, it is important to incorporate strat of buildings, providing operable openings or shading (for better ventilation or solar protection), etc.
hermal stress—a significant increase from 91 “Strong Heat Stress” days in 2020 to 426 “Strong Heat Stress days by diurnal averages charts of 2020, 2050 and 2080, the data shows there will be a steady increase in temperatures. tegies that focus on cooling over the summer and heating over the winter. These strategies may include orientation
02 Solar Access
ANALYSIS The site is situated on a steep slope, but with the efforts of urban relandscaping, it is now divided into varying levels. The north-facing side of the site has a concrete wall built between E State Street and the parking lot, which created a significant level change in the landscape. The south-facing side neighbors a partial segment of the Six Mile Creek that runs across Tompkins County, and the creek is slightly sunk below the level of the site. With its unique landscape leveling, the site is an ideal middle host that connects the nature of the Six Mile Creek with the rest of the urban landscape in Ithaca.
COLOR LEGEND Sun Hour on Surface - solar exposure most sun hours fewest sun hours
Subtractive Method - obstruction index most sun productivity least sun productivity
Solar Envelope - overshadow prevention Green - buildable volume Blue - surrounding buildings Red (lining) - areas to avoid overshadow
SUN HOUR ON SURFACE ANALYSIS, SUBTRACTIVE METHOD ON SOLAR FORM FINDING + SOLAR ENVELOPE ANALYSIS
SUN HOUR ON SURFACE: Southeast view The building surfaces facing the south and east side receives the most number of sun hours throughout the year. There is a reasonable amount of distance between the site and the slope on the other side of the creek that prevents any overshawdowing.
SUBTRACTIVE METHOD: Southeast view The south-facing side of the building receives the most productive amount of sunlight. However, the north-facing side not so much, therefore, could be subtracted from the potential building volume.
SUN HOUR ON SURFACE: Northwest view The building surface facing north receives the fewest number of sun hours because there is a concrete wall in close distance that blocks solar access. The west-facing side also loses sun hours because of the building blockage nearby.
SOLAR ENVELOPE: Southeast view The volume of the solar envelope shows a generous amount of extra height that the project can use without overshadowing the surrounding buildings. The buildings around the site sit on a slope, therefore, they are on a higher elevation than the site. The high elevation puts them on an advantage against any overshadows.
DESIGN STRATEGIES
ITERATION #1: More solar exposure on north-facing side The building surface facing north receives the fewest number of sun hours because there is a concrete wall in close distance that blocks solar access. From the sun hour analysis, the data model shows that the roof has a high number of sun hours. This shows that it is an ideal area in the building that has solar access. Design strategy: Roof angle Since the roof has a high sun exposure, the roof is angled to strategically introduce sunlight into the north-side. This strategy is done according to the sun productivity volume generated using the subtractive method. This helps significantly increase sun hours. The angle of the roof can also be adjusted to control the amount of sunlight exposure.
ITERATION #2: Control sunlight exposure The building surface facing south receives the highest number of sun hours. This amount of sun exposure may be too excessive, and may lead to building problems such as glare and thermal discomfort. Design strategy: Sun shade A sun shade is added in front of the building in a strategic triangle shape. This adjusted the sun hours to a moderate amount. The point of the triangle that sits on the site ground can be adjusted in its eastwest axis (left-right), which influences the shading coverage of the south-facing building surface.
FINAL DESIGN STRATEGY: ROOF OVERHANG
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In the final design, a roof overhang is featured on the south-facing side of library building. It extends to a length that allows sun blockage during the summer solstice, but allows sun exposure during the winter solstice.
03 Renewable Energy Potential SUN HOUR ON SURFACE ANALYSIS, RADIATION MAPPING + ANALYSIS, PV PANEL PLACEMENT + BUDGET, LOAD MATCHING
COLOR LEGEND Sun Hour on Surface - solar exposure most sun hours fewest sun hours SUN HOUR ON SURFACE: Southeast view The building surfaces facing the south and east side receives the most number of sun hours throughout the year. Taking glazing placement into consideration, it is ideal to place PV panels on the 4 roof surfaces highlighted below:
ENERGY + CARBON FOOTPRINT Hot water load (gas/electric) [kWh/m2] - COP 2.5 Heating load (gas/electric) [kWh/m2] - COP 2.5 Cooling load (electric) [kWh/m2] - COP 3 Site energy use [kWh/m2/a] - 131 Energy cost [$/kWh] - 0.2 Energy cost per area per year [$/m2/a] - 26 Energy use intensity [kg CO2/m2/a] - 65
4 panels (roof coverage only), 2000m² floor area 1st data set: battery set to 0 kWh, net load match (annually): 0.641621, hourly load match: 0.318598. 2nd data set: battery set to 200 kWh, net load match (annually): 0.569808, hourly load match: 0.469128. From the two sets of data, it is shown that PV panels do not perform as effectively when battery is inserted. Import energy significantly decreases because of battery usage demand.
7 panels (roof + facade coverage), 2000m² floor area 3rd data set: battery set to 0 kWh, net load match (annually): 0.888978, hourly load match: 0.360338. 4th data set: battery set to 200 kWh, net load match (annually): 0.78195, hourly load match: 0.561278. From the two sets of data, it is shown that PV panels do not perform as effectively in the annual time scale when battery is inserted. Import energy significantly decerases because of battery usage demand.
CONCLUSION - Additional facade coverage greatly increases load match, bringing the building performance closer to net zero. - Battery state fails to even out the energy load and exported energy of the building. Therefore, they tend to not perform as effectively as having no battery usage.
04 Building Energy Model (BEM) SITE CONDITIONS + BASE CASE The image on the left shows my most recent development in studio (in terms of form finding). The south-facing facade is where most sunlight exposure is captured and is therefore, mainly glazing to increase heat gain (especially beneficial over the winter). The material for the facade and roof are changed and compared throughout iterations in this assignment. The site EUI is initially measured to be 689.9 kWh PE/m2/a, which is relatively high and the goal of each iteration is to minimize it as much as possible. BASE CASE: PERFORMANCE Site EUI (kWh PE/m2/a) = 689.9 AIA Site EUI Baseline (kWh PE/m2/a) = 1167.2 $/m2/a = 34.5 kg CO2/m2/a = 199.3
ITERATION #1: PERFORMANCE + ANALYSIS Site EUI (kWh/m2/a) = 607.1 $/m2/a = 30.8 kg CO2/m2/a = 177.7 To avoid change of program massing, it is a very intentional decision to control the EUI through material usage rather than form alteration. Therefore, the material choices have been strategically chosen to have lower U-values as the lower translate to better insulation and reduces energy loss. The roof and facade material choices are especially designed for Climate Zone 5 according to CliamteStudio data, which is beneficial as the library is situated in Ithaca which is in Climate Zone 5. A double layer type of glazing is chosen to withstand cold temperature/weather penetration. The improvement of data justifies these material choices. The EUI has decreased by 20 KWh/m2/yr, resulting in a 82.8 KWh/m2/a decrease in site EUI. The loads of the library has also decreased significantly by a 30,000 KWh margin.
ITERATION #2: PV PANEL A PV panel is placed on top of the flat-slating roof, and the data below shows its performance:
ITERATION #2: PERFORMANCE + ANALYSIS According to the simulation data, the total solar power that the PV panel generates annully is 261,725 kWh. This translate to 131 kWh/ m2/a as the final site EUI (given that the building area is 2,000 m2).
EUI
ITERATION #1: MATERIAL CHOICE The material for the roof, facade, and glazing have been altered to be the following instead:
CONCLUSION With a strategic round of material selection and installment of PV panel, the site EUI was able to decrease from an alarmingly high site EUI of 689.9 kWh PE/m2/a to a much lower site EUI of 131 kWh/m2/a, bringing the building closer to net zero.
BASE CASE
MATERIAL
PV PANEL
iterations
05 Detailing
WALL Limestone blocks (2’) Rigid insulation (10”) Gypsum board (1/2”)
ROOF Glulam beam (6x18) Glulam decking (6”) Rigid insulation (10”) Standing seam metal cladding (2”)
BASE CASE From the temperature simulation, it is evident that heat / warm temperature from the interior is escaping from the awkward gap between the roof girder and the stone wall. There are general directions where they are escaping to the roof and to the stone wall. ITERATION A plywood block is placed in the gap among the roof, girder, and stone wall—which is where all the heat is escaping to in the first place. From the rerun of the temperature simulation, it is evident that the plywood block has helped stop the heat from escaping, by creating a thermal bridge.
Ψ = -0.053 W/mK UA,2d = 0.094 W/m2K UA,1d = 0.154 W/m2K UB,2d = 0.153 W/m2K UB,1d = 0.153 W/m2K ΦTOTAL = 13.462 W/m L2D = 0.538 W/mK ΔT = 25.0 oC
Ψ = 0.019 W/mK UA,2d = 0.183 W/m2K UA,1d = 0.154 W/m2K UB,2d = 0.153 W/m2K UB,1d = 0.153 W/m2K ΦTOTAL = 15.267 W/m L2D = 0.611 W/mK ΔT = 25.0 oC
06 Daylight + Visual Comfort AUDITORIUM Facing the west side of the library, the auditorium cantilevers over the entry of the parking structure that is below the building. The auditorium features large glazing, and it is meant to allow view access to the urbanscape of East State Street.
POINT-IN-TIME ILLUMINANCE
MATERIAL CHOICE Floor: concrete Partition walls: wood panels Roof: CLT, glulam decking OCCUPANCY PROFILE - max. 60 occupants - for educational use, i.e. lectures, meetings
DAYLIGHT AV
DATA ANALYSIS From the daylight availability data, it is evident that the auditorium receives a large amount of daylight, with most point areas receiving more than 80% each day (refer to daylight availability simulation image). From the point-in-time illuminance data, it shows the inevitability of areas closer to glazing having stronger daylight exposure. Though that is the case, the exposure still remain at a comfortable level and not excessive. From the glare analysis data, it can be seen that glaring is most severe near glazing, as well as near partition walls, which might be because of the reflectiveness of the material.
VAILABILITY
GLARE ANALYSIS
GLARE ANALYSIS: BASE CASE
GLARE ANALYSIS: NEW ITERATION
ILLUMINANCE TARGET The lighting target is to create a close to uniformly distrubuted lighting to the space, in attempt to clear visual discomfort and distractions from viewing the lecture boards/slides that are in front of the room. SOLUTION TO GLARING ISSUES To tackle glaring issues that are closer to the glazing, the roof overhang can be extended to block out more daylight exposure. To tackle glaring issues that are closer to the partition walls, another wood material with lower reflectiveness can be chosen to prevent incoming daylight from glazing direction from bouncing off of the reflective walls. ANALYSIS TO NEW ITERATION With the roof overhang extended and a material change to the partition walls (the material is more matte than glossy in this iteration), the overall sDG has decreased from 44.4% to 37.7%. From the simulation images, it is also evident that there is less glaring near the partition walls (as shown with the gradient: less yellow, more white; meaning glaring is not as severe as before).
07 Conclusion
Throughout the studio project, there were several important considerations that deeply influence the outcome of aesthetics and functionality of the library building. Those are: 1) South-facing situation of the building - The south side of the site is where most of the daylight would be captured, and that is also where the front (or main) facade of the library building is. 2) Incorporation of large glazing on the south side - This must be carefully considered as it may lead to visual discomfort due to over exposure of daylight and glaring issues. 3) Connection details between stone wall/columns and timber roof - The construction of these details must be decided with the consideration of thermal bridging. In the ES simulations, the data was able to help identify solutions to the above considerations. There were some failed design iterations that were scrapped because of the concerning data that some simulation showed. For example, the data from 03 Renewable Energy Potential showed that a multi-paneled roof may not best capture the solar energy that the south side of the site abundantly receives, which is why the iterations in that assignment did not make it to the final design of the library.