Introducing the Housing Attainability Explorer

Author: Eric Kronberg

Editors: Carrie Whitney, Darby Fly

What kinds of homes can fit on a single lot—and how might their estimated development costs compare with locally relevant income benchmarks?

KUA’s new Housing Attainability Explorer is a beta planning tool designed to help communities, developers, and housing advocates explore those questions. 

With this tool, users can assemble a mix of housing types from our Housing Choice Catalog, adjust basic cost assumptions, and compare the resulting planning-level costs with benchmarks derived from HUD income-limit area data. 

The Explorer offers insight into the financial implications of your planning choices, but you must do your own site planning to determine what is possible on a specific site.  

This is a tool intended for early conversations. It can help users compare initial feasibility of different unit mixes, test the effect of land and construction costs, and identify concepts that may warrant further study. It is particularly useful for illustrating how sharing land across several homes can affect per-unit costs.  

Just as importantly, the Explorer is not a development pro forma. It does not replace contractor pricing, project underwriting, an appraisal, a market study, or professional financial advice. Its estimates do not automatically account for financing costs, taxes, insurance, developer return, construction contingency, escalation, unusual site conditions, or every permitting and regulatory expense. The affordability benchmarks are planning comparisons—not loan qualifications, official home-price limits, or housing-program eligibility determinations.

A favorable result does not establish that a project is feasible, financeable, or marketable. But it provides a starting point for asking better questions.  The Explorer is exceedingly useful for:

• Comparing initial outcomes of different land use policy choices

• Testing potential construction costs for particular land parcels 

• Considering the effects on per-unit costs

• Looking at housing price targets for a specific zip code relative to different AMI levels

• Identifying areas for further study

We currently have the tool set up to only look at for-sale housing, with a key assumption that each unit on a multi-unit lot could be sold separately. That is a huge assumption that often conflicts with local zoning laws.  

The other big cost item to flag is that it will apply soft costs and horizontal costs on a per unit basis.  This means if you show 4 homes, those costs will be multiplied by 4.  Each additional unit adds costs to those, but likely not at the full freight of a single unit.  You need to use personal judgement as to how high or low those inputs should be.  

Because the tool is in beta, its assumptions, source data, and calculations may continue to be refined. Users should verify all results with current local cost information, site-specific analysis, and qualified development, design, and financial professionals before making project decisions.

Used within those limits, the Housing Attainability Explorer can make the relationships among housing choice, land, cost, and local incomes easier to visualize—and give communities and developers a more concrete place to begin.