Link to Student
Journal Entry For
Module 7 - Study Your Options
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I wanted to design a open office (single story) building in Boston where the weather is too cold and snowy.
- Design Decision 1: Ideal Architectural Design & Roof design for PV panels
- Design Variables
- Number of Sides in the Polygon Profile
- Height of the building
- Top most point of the roof (to decide whether slanted roof is good or not)
- Windows opening ratio
- Evaluators
- Cost of the Building (Roof, Windows and Floor area)
- Solar insolation values of Window Surfaces
- Building Surface Area
- Building Volume
- Solar insolation values of Roof surface
- Most Important Tradeoffs to Consider
- As height of building and top most point of the roof increases cost of the building increases
- As opening ratio of the window increases, the framing metal area decreases thus decreasing the cost (the open glass area increases when framing area decreases, but for the scope of this assignment it is not accounted)
- For a given building surface envelope area, the volume (the open office space) of the building is greater for the building with more number of side in its base profile
- Roof area increases with increase in height of top most point but again, the building cost might increase
- Design Decision 2: Sustainability
- Design Variables
- Type of material for the structural frame
- Different Material Suppliers
- Choice of MEP systems: Solar Powered or Natural Gas
- Energy production from PV panels
- Evaluators
- Embodied Carbon of the materials
- Carbon Footprint from Transportation of materials
- Operational Carbon Footprint
- Cost of Material procurement and MEP system (including PV panels)
- Most Important Tradeoffs to Consider
- Transportation cost of materials from nearby suppliers will be less but if the materials from that supplier that high embodied carbon then the carbon footprint increases, this needs to be consider while optimizing
- Cost of Solar Powered and efficient MEPs might be higher but their operational carbon footprint will be usually less
- Cost of PV panels increases with their increase in efficiency
- Design Decision 3: User Comfort
- Design Variables
- Placement of windows or view points
- Window opening area
- Floor Area
- Capacity of the building
- Evaluators
- Percentage of line of sights from the viewpoints that intersect with the nearby buildings
- Floor area per person
- Heating load
- Cost of the building
- Most Important Tradeoffs to Consider
- Lesser is the percentage of obstruction and more is the number of view points, more will be the view quality, but this will increase the cost
- More is the window opening area, higher will be the view quality but this will increase solar heat gains
- The more spacious the office is, the more will be the user comfort, but again the capacity and the floor area should be looked thoroughly to get the ideal floor area per person person value as the cost of the building increases with increase in floor area
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Step 2 - Generative Design Study
- For this assignment, the first design decision: “Ideal Architectural design and roof area for PV Panels” was chosen
- Design approach:
- Building profile is a regular polygon which was created using inscribed circle. Base profile is created with base radius being constant and it was translated in z-direction to create top profile. Number of sides of the polygon, height of the top floor are design variables
- Then, Surface.loft was used to sweep the area between these two profiles and Topology.faces was used to list all the faces of the building
- The top most point for the slanted roof is given as design variable which is nothing but origin translated to some distance in z-direction. If it is 0 then we will be having a flat roof
- The roof was then panelized to account for PV Panels
- Windows are placed at specific points such that number of windows at each face of the building equal to number of sides of the polygon profile .T
- The geometry of points for the 4 point Revit family for windows are found out using Surface.PointAtParameter. 0,1 are removed as we don’t want to have windows on the edges of the building.
- Opening Ratio of Windows: opening ratio parameter of the Revit panel family was used in order to analyze how solar insolation values on window surfaces changes with change in opening area of the window
- Evaluators:
- Surface Area and Volume:
- Cost: Cost of building surface area, floor area, windows were included and calculated as follows
- Solar Insolation:
Custom node solar_insolation_surface was created as discussed in previous Modules. Shaded surfaces can be found in the Revit file which were create using “Box” mass element to simulate the surrounding buildings. We need to have more insolation values for both roof and wall so that we can produce more solar energy and more solar heat gain to minimize heating loads in the cold climate like Boston, respectively. Note: Location was set to Boston
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Step 3 - Generative Design Study Results
- The screenshot of the Scatterplot or Parallel Coordinates Graph illustrating the tradeoff that you chose to model and study.
- Provide a brief explanation of what’s being shown in the Scatterplot or Parallel Coordinates Graph and how the tradeoff being illustrated would impact the design decision. What would you do with this info?
- An image of your Dynamo Study Graph (showing all your nodes and the connecting logic):
- Scatter Plots:
- Surface area vs Volume for different number of sides: Area and volume are linearly dependent and for a given volume surface area will be less for profile with more number of sides (blue color). So, to minimize surface area and maximize volume we need to have higher number sided-polygon
- But the problem with more number of sides is the cost will be high as shown in the below scatter plot:
- The amount of solar incidence on windows (solar insolation) is highest for buildings with 5-sided polygon profile (pentagon: light green color code)
- And the window solar insolation value remains more or less the same with increase in opening ratio
- The energy generation potential of PV panels when placed on the roof will be higher for buildings with lower number of sides. And it is also cheaper compared to their higher number sided polygon building counterparts.
- From some of the above analysis, we can say that the trade-offs are not consistent for all the evaluators. So to tackle this, weights must be assigned to each evaluator to find the optimal solution
