Draw boundaries around actual choices

Start with the proposed product and the activities shaping its use. Examine routes to employment, everyday services and other destinations the customer actually values. Consider physical barriers and realistic travel conditions, not only straight-line distance. Then compare the prices and unit characteristics on both sides of your proposed boundary. A jurisdictional line may matter for taxes or services without defining the entire competitive search area.

Test a site beside a county line

For a fictional rental site beside a county line, assemble an initial nearby comparison set. Add a property across the line with similar units and an easier commute, then remove a closer property whose price and use serve a different customer. Write down both decisions. Repeat the rent and availability review with a wider boundary. If the conclusion changes sharply, the investment thesis depends on the boundary and needs more customer evidence.

Show sensitivity to the boundary

Avoid drawing a submarket simply to exclude cheaper competition or justify a desired rent. Small samples can make local averages unstable, while broad samples can erase meaningful differences. Show both the narrower product comparison and the broader context with their limitations. Continue with the product-specific absorption guide to define an occupied-inventory measure that uses the same boundary, product and observation period throughout the analysis.

Take the next step

Continue with the related guide

General information—not personalized legal, tax, investment, engineering or architectural advice.