Portico is an example of a computational law system in the context of building codes. The system allows you to load a previously created building design; it presents a three-dimensional rendering of the design; and it allows you to modify the building in a few ways, e.g. making it larger, making it taller, and moving the building around on the parcel. As you make changes, the system assesses the compliance of the design with regulations on footprint, height, setbacks, and shadow lines; and it automatically updates its assessment as the user makes changes. When asked, the system provides explanations for its assessments.

Load the Portico Demonstration to see the system in action. Adjust the sliders to see the building from different points of view. Click the Turn button to increase the speed of rotation; click the Stop button to decrease the speed or stop the rotation. Click Larger or Smaller to change the horizontal size of the building; click Taller or Shorter to change the height. Click and drag the building to move it around the parcel. As you perform these operations, you will notice that the display either remains blue, indicating compliance with all regulations, or it turns red, indicating a violation.

The table on the left at the bottom provides qualitative information about the building and the parcel - its zone and whether or not it is a substandard lot, a flag lot, or in a flood zone - and it allows you to change these bits of information.

The table on the right gives numerical values for the leftmost and rightmost points of the building, the foremost and rearmost points of the building, and the bottommost and topmost points of the building. These change as you change the size of the building or move it around on the parcel.

The table in the center presents the system's analysis. Each row consists of a particular standard, the actual value associated with that standard, the allowable minimal or maximal value for that item, and a check mark indicating whether or not the building is in compliance. Clicking on a value in the table produces a pop-up explaining how the system arrived at that value.

The compliance rules used by the system are based on the planning standards for the City of Palo Alto. Click here for a simplified version of these rules written in English that closely resembles the actual text in the City's regulations.