Quantitative and spatial analyses of proposed land use policy changes in Hawaii. Relies heavily on the Hawaii Zoning Atlas.

The repo is organized as follows:

• All code lives in the root folder
• Datasets live in the data folder
  • islands contains outlines of each county. Useful for clipping.
  • lege contains State House and Senate districts as of the 2020 redistricting. Necessary for district-level analysis.
  • zoning_maps contains spatial versions of the Hawaii Zoning Atlas data. Spring 2024 vintage.
  • zoning_text contains non-spatial versions of the same.
  • Also included: datasets that have been used for one-off analyses (parcels, SMA, SLUD, etc.)
• Tables and charts live in the output folder
  • of note: the by_district subfolder is generated iteratively by house_district_analysis.ipynb

• SOH SB 3202 (2024) - Passed as Act 39. Requires counties to adopt policies that will permit 2 ADUs on most residential parcels.
  • conference_analysis.ipynb maps the effective area of the final (conference) draft of the bill, which excludes certain State Land Use Districts, Special Management Areas, and hazard areas. Outputs tables and maps.
  • house_district_analysis.ipynb calculates single-family zoning area by House District to understand the impact that the Starter Homes Bill might have on each district. Includes handy code for creating a statewide zoning dataset, and for iteratively generating tables and graphs for each district.
  • sb3202.ipynb explores an intermediate draft of the bill. Useful mainly for reference in using KML files, and in grouping and mapping zones.

• Maui Bill 103 (2024) - Proposal to increase the number of units allowed per parcel in residential areas from 1 per 6000-10000 sqft of lot area to 1 per 2500. Excludes Molokai.
  • maui_density_bill.ipynb joins Maui zoning and parcel data to explore the potential impacts of the bill on zoned capacity.
  • Processed spatial dataset is stored as data\maui_gdf.geojson.
  • Tabular results are exported as output\maui_nui_parcels_with_zoning.csv.

• TBD

• Hawaii Bill ___ - major update to land use ordinance. I can't remember the bill # right now.
  • county_analysis.ipynb is an incomplete county-level exploration of HZA data.

The Hawaii Zoning Atlas is a comprehensive statewide dataset of zoning regulations with a focus on housing. The data is free for non-commercial use and the latest (Spring 2024) vintage be found as final.geojson in the CodeWithAloha/Hawaii-Zoning-Atlas repo. That README includes more background on the creation of the dataset.

For a data dictionary, see How to Make a Zoning Atlas 2.0: The Official Methodology of the National Zoning Atlas. The use of a national data standard allows researchers to compare Hawaii with other jurisdictions and with itself over successive policy changes.

HZA kickoff - the first 25 minutes of this video include a discussion of exclusionary zoning in Hawaii, a demonstration of the Atlas, and potential applications of the underlying dataset.

Regulatory utilization - HZA director Trey Gordner's masters thesis discusses how to use open GIS data (like the zoning atlas, which came later) to estimate the restrictiveness of land use regulations.