Building permits vs. housing starts: how to read a local supply pipeline

Building permits count housing units authorized for construction. Housing starts measure construction beginning; completions measure construction reaching the Census Bureau's defined completion stage. A county's permit total therefore cannot tell you how many competing homes will open next year. For a land acquisition decision, use permits to identify projects worth investigating, then track those projects through construction and delivery.

The distinction matters even at the national level. In its 2025 comparison, Census reports that housing completions were 9.8% higher than housing starts. That is possible because homes completed during a year can have started in earlier years. These totals describe activity during a period, not a single group of homes moving through a funnel. Census explanation of permits, starts, and completions

Choose the series that answers your question

The Building Permits Survey provides local authorization statistics, including county and permit-issuing-place data. The Survey of Construction provides national and regional starts and completions estimates. Do not put a county permit count beside a regional starts count and describe the ratio as that county's construction conversion rate.

For a local study, decide which question you need to answer:

• How much residential construction was authorized in this jurisdiction during the period? Start with the permit series.
• Which projects near my proposed community have begun construction? Gather project-specific evidence from local records and dated observations.
• Which competing units may become available during my delivery window? Track each project's phase and the evidence supporting its expected availability.

Census counts housing units, so a new apartment building can contribute many units to the total. A local portal may instead show permit records for buildings, phases, or individual scopes of work. Read the field definitions before counting rows. Census also notes that a permit-issuing place can cover a municipality, a county, or a combination of municipalities. Check the geographic footnotes when comparing nearby places. Building Permits Survey definitions

Keep the same projects together

Suppose you are comparing a January-through-June permit export with a June construction-status export. The following numbers are invented to show the method; they do not describe a real market.

The permit export contains 600 authorized units. Of those same 600 units, the June review finds:

• 250 units with no verified construction start.
• 200 units under construction.
• 150 units completed.

A separate project with 120 units is also under construction in June, but its permits were issued the previous year.

Adding 600 authorized units to all 320 units under construction produces a misleading total of 920. The 200 units from the current permit group appear in both figures. In this simplified example, the two exports cover 720 distinct units: 250 not verified started, 320 under construction, and 150 completed.

If your question is remaining physical delivery, the 150 completed units belong in a separate category. That leaves 570 units whose construction is either unfinished or not verified started. Even that number is not a delivery forecast. The 250 unstarted units need further investigation, and some completed units may still be competing for residents or buyers.

This calculation only works because the example matches each unit to one project and one current status. You cannot reproduce it by subtracting unrelated aggregate Census series.

Verify timing without inventing a universal lag

A permit date is a useful starting point for follow-up. It does not establish a move-in date. Census documents several reasons the stages diverge, including abandoned projects, changes in unit counts, and shifts in the inventory of work still under construction. A fixed rule such as "all permits become supply in 18 months" hides those differences. Census data relationships

Ask for evidence tied to the actual project or phase. A grading observation, a building inspection, and a developer's advertised opening date each answer a different question. Record the date and what the source establishes. When two sources disagree, retain the conflict until you resolve it.

Also distinguish the metric you collect from the one you report. Census has specific completion definitions, including a building-level rule for structures with multiple housing units. A local certificate of occupancy, a leasing launch, a home closing, and Census completion are separate events. Survey of Construction definitions

For a phased subdivision, use separate phase rows when the evidence permits. Assigning the first phase's expected delivery date to every planned lot makes a long project look like an immediate supply surge.

Use a project record you can update

Copy this suggested worksheet for each competing project. It is an editorial template, not a Census form.

Project name and address:
Parcel IDs and jurisdiction:
Project / phase identifier:
Unit count and housing type:
Count basis: units / buildings / permit records

Authorization source and date:
Authorized units for this phase:
Construction status and observation date:
Evidence supporting that status:
Completed units and definition used:
Availability or delivery estimate:
Who supplied that estimate, and when:

Earlier records referring to this same project:
Duplicate rows or amendments resolved:
Unresolved differences:
Next verification action and owner:

Keep the permit export's reporting period, download date, geography, and revision status with the file. The Building Permits Survey includes estimates for missing reports, and annual data can revise earlier totals. A change between downloads may reflect reporting as well as new activity. BPS collection and estimation methods

Bring the findings back to the land decision

Summarize the projects relevant to your intended housing product and delivery window. Show verified construction separately from authorized projects whose start remains uncertain. Identify the projects most likely to change your assessment if their timing or unit count moves.

Keep that market work alongside the parcel research in your land sourcing process. Then use the site screening guide to investigate the candidate's own constraints. Nearby permits can justify a closer look at competition; they do not establish either demand for your project or the site's ability to support it.