What does it do?
The Prototype Builder is a planner-friendly Return on Investment (ROI) model similar to the models developers use to evaluation the financial feasibility of potential projects. The Prototype Builder is an intergral part of the Envision Tomorrow scenario planning process. The tool is used to create the building library used in scenario painting, but also has significant utility as a stand-alone tool.
As a stand-alone tool, the Prototype Builder is used to analyze the market feasibility of building types. It helps planners determine whether zoning and development codes will actually result in desired development outcomes given current and future market conditions. It can also be used to identify how various policy changes affect building type feasibility and how much funding may be needed to make desired development types “pencil out.” This can include direct subsidies for individual projects as well investments in public amenities that tend to increase average rents in a community and open up new development opportunities.
How does it work?
The Prototype Builder allows users to "construct" virtual buildings by changing physical and financial data to assess the return on investment for different building types. Physical (height, unit size, parking requirements, etc.) and financial (land cost, average rents, parking costs, etc.) parameters are input into a pro-forma to determine a hypothetical developer’s return on investment for a project. Leveraging tools such as loans, grants, and tax credits can be added to assess the impact of these tools on a project’s return on investment. The market impact of public amenity investment can also be used to alter inputs to determine the effect on project feasibility from higher average rents.
Generic, national-level inputs are preloaded for many of the variables in the Prototype Builder. Local refinement is important and research should begin early in the scenario planning process. Online resources such as LoopNet, Zillow and even Craigslist can be helpful for establishing current rent ranges for various land uses. In addition, focus groups or interviews with experts in the development, property management, real estate and lending industries can be invaluable for both gathering and checking market research data.
Green infrastructure – green roofs, rainwater harvesting, rain gardens – is an alternative to conventional "grey" infrastructure used to remove water pollutants from stormwater runoff. In addition to generally being more effective at removing water pollutants, it provides many other additional environmental, economic, and aesthetic benefits. The Green Infrastructure App allows consideration of water quality needs when modeling a building and a scenario in Envision Tomorrow and quantifies several of the many benefits of green infrastructure.
At a site level, it estimates the volume of water that should be captured to meet water quality standards and allows the user to select from a variety of controls, including green infrastructure, to capture that volume. It will estimate the costs of the controls and the impact on the return on investment. The app will also estimate the amount of key water pollutants expected and the effectiveness of the controls selected in removing those pollutants.
For a planning area, the app will estimate several of the many additional benefits when green infrastructure controls are selected. These benefits include:
- Runoff reductions
- Energy savings
- Air pollutant reductions
- CO2 reductions
- Potential open space and habitat
The app will also profile how stormwater is handled across a planning area, providing some initial insight into opportunities for district-wide stormwater management.
The Green Infrastructure App is integrated into both the Envision Tomorrow Prototype Builder and the Scenario Builder. The Green Infrastructure tab in the Prototype Builder uses information calculated or input elsewhere in the Prototype Builder to estimate water volumes, the size of water quality controls, and the expected amount of runoff pollutants. Required water quality volumes are based on the expected impervious cover. Users have the option to use preset buttons that select and size controls given the building footprint, landscaping area, and parking area calculated by the Prototype Builder. These controls include:
- green roofs
- green roofs connected to a cistern
- biofiltration facilities
- rain gardens
- conventional sedimentation-sand filters
Design settings for controls may be manually adjusted. Using default costs, which may also be adjusted, the app estimates the costs of these controls and their efficiency in removing four key water pollutants that indicate the level of turbidity, nutrient loading, contaminant levels, and disease-causing bacteria levels. Expected pollutant levels are based on the building uses selected in the Prototype Builder.
Based on the controls selected for individual building prototypes, the app will aggregate associated information across a planning area in the Scenario Builder. For green infrastructure controls, it uses formulas found in the Center for Neighborhood Technology guide, The Value of Green Infrastructure, to estimate additional environmental and economic benefits. The app will also create a stormwater facility profile and estimate the removal of key pollutants across a scenario planning area by aggregating information from the Prototype Builder portion of the app.