Vacancy, Availability and Absorption: What Each Measure Tells You
Three common market measures sound alike but answer different questions. Clear definitions and a small example.
Market reports for offices, apartments and industrial space use a small set of recurring measures. Vacancy, availability and absorption are three of the most common. They are related, but each answers a different question, and mixing them up leads to wrong conclusions.
Vacancy rate
The vacancy rate is the share of total inventory that is physically unoccupied at a point in time. It is a snapshot. A building with a tenant that has stopped using its space but is still paying rent is usually counted as occupied, not vacant.
Availability rate
The availability rate is the share of inventory being actively marketed for lease. It includes vacant space and occupied space that will become available soon, such as space a tenant plans to leave or offers for sublease. Availability often moves before vacancy, which makes it a useful early signal in office and industrial markets.
Net absorption
Net absorption is the change in occupied space over a period: space newly occupied minus space vacated. Positive absorption means occupancy grew. It is a flow measure, not a level.
| Measure | Start of year | End of year |
|---|---|---|
| Total inventory, sq ft | 10,000,000 | 10,400,000 |
| Occupied space, sq ft | 9,000,000 | 9,150,000 |
| Vacancy rate | 10.0% | 12.0% |
| Net absorption for the year | — | +150,000 sq ft |
In this example, absorption is positive, meaning more space is occupied than a year earlier. Yet vacancy rose, because 400,000 square feet of new space was delivered. Both statements are true at once.
Common pitfalls
- Treating a rise in vacancy as falling demand without checking new supply.
- Comparing figures from providers that define inventory differently, for example by building size or class.
- Ignoring sublease space, which can be a meaningful part of availability.
Reading the three together
A useful habit is to read the three measures as a short story. Availability rising while vacancy is still low suggests tenants are planning to leave or shed space. Vacancy rising alongside positive absorption suggests new supply is the main driver. Vacancy rising with negative absorption suggests tenants are actually giving back space. Each story leads to different questions about rents, leasing incentives and future construction, which is why analysts rarely rely on a single measure.
The same logic applies to apartments, where vacancy, leasing velocity and new deliveries are often reported together. Whatever the property type, comparing the three measures over several periods gives a far more reliable picture than a single quarter.
Why it matters for U.S. real estate
Leasing strategy, rent expectations and development decisions all rely on these measures. Reading them together explains whether a market is softening because tenants are leaving or because supply is arriving.
Limits of this view
Definitions vary across data providers and property types. Always check the methodology for what counts as inventory, occupied and available before comparing reports.
Educational content. This article explains general concepts. Examples use hypothetical figures and are not market data. Nothing here is individual investment, legal, tax or appraisal advice. See our editorial standards and disclaimer.
