Monami Waki

Journal Entry For
Module 9 - Make Your Pitch
ACC Folder Link
Link to Student

High-Performance Roof Prioritization Assistant

Intended users

  • Architects designing high-performance buildings
  • Sustainability consultants seeking optimal roof strategies for LEED / resilience / carbon reduction based on client priorities
  • Building owners and developers making investment decisions about rooftop PV, green roofs, and stormwater management

Need you’re trying to provide a solution or support for

Designers and owners face complex trade-offs when allocating roof space between solar PV, green infrastructure (green roofs / stormwater retention), and managing structural costs. Decisions typically prioritize one factor (cost or sustainability), without a holistic view of combined performance. This tool helps users make informed, balanced design choices by calculating an aggregate Sustainability / Resilience / Cost Score based on user-defined priorities — supporting transparent decision-making in early design phases.

Inputs

  1. User-defined priority weights (%)
    1. Sustainability Weight (%) → prioritizes operational emissions reductions
    2. Resilience Weight (%) → prioritizes stormwater retention benefits
    3. Cost Weight (%) → prioritizes minimizing net cost
  2. Design Variables
    1. % of roof area allocated to PV, % of roof area allocated to green roof
    2. Location (to determine feasible electricity generation per square foot)
    3. Structural system parameters (allowable load)
    4. Financial factors (PV costs, green roof costs, utility rates, incentive rates)

Underlying logic of the model

  • Each dimension (sustainability, resilience, and cost) is scored on a 1-10 scale based on performance
    • Sustainability: tCO₂e emissions avoided (via PV + battery) → mapped to category 1-10
    • Resilience: % stormwater retained → mapped to category 1-10
    • Cost: Net cost = (PV cost + green roof structural cost) - avoided utility costs → mapped to category 1-10 (lower net cost = higher score)
  • User-input weights are applied to each score
    • Overall score = (Sustainability Weight × Sustainability Score) + (Resilience Weight × Resilience Score) + (Cost Weight × Cost Score)
  • The tool automatically evaluates various combinations of roof allocation (PV vs green roof) to identify options that best align with user-defined priorities.

Outputs

  • Overall Sustainability / Resilience / Cost Score for each evaluated design option
    • Visualization: Parallel coordinates and scatter plot of design options, highlighting where overall scores are the highest
  • Breakdown of:
    • tCO₂e saved annually
    • Volume of stormwater retained
    • Net system cost and payback period
    • Structural costs from the green roof