Availability rate is the percentage of a market's total rentable space that is being marketed for lease, whether or not it is currently occupied. It divides all space actively offered, including vacant space and occupied space whose lease is expiring or being subleased, by the total inventory. It is a forward-looking signal of supply that typically runs higher than the vacancy rate.
What Is the Availability Rate?
The availability rate measures how much space in a market is on offer, capturing both empty space and space still occupied but openly marketed. Per CBI Commercial, the availability rate is the proportion between the total space being marketed and the total inventory, and it includes vacant space plus space occupied by a tenant whose lease is about to expire or who is offering it for sublease. This makes it broader than vacancy, which counts only physically empty space.
Because it includes occupied-but-marketed space, the availability rate is a leading indicator. It reveals supply coming to market before that space actually empties, giving tenants and landlords an earlier read on competition.
Space type | Counted in availability | Counted in vacancy |
|---|---|---|
Vacant and marketed | Yes | Yes |
Occupied, lease expiring, marketed | Yes | No |
Occupied and offered for sublease | Yes | No |
Occupied and not marketed | No | No |
How Is the Availability Rate Calculated?
The availability rate is calculated by dividing the total space being marketed for lease by the total rentable inventory, then multiplying by 100. The numerator includes every square foot on offer, whether vacant, expiring, or listed for sublease. The denominator is the full inventory of the market or building.
Symbol | Meaning |
|---|---|
A | Total square feet being marketed for lease |
I | Total rentable square feet in the market or building |
Availability rate | (A divided by I) times 100 |
The distinction from vacancy sits entirely in the numerator. Vacancy counts only physically empty square feet, while availability adds occupied space that is being actively marketed, which is why availability is usually the larger number.
Why the Availability Rate Matters
The availability rate matters because it shows real competitive supply, not just empty rooms. A market can look tight on vacancy while a wave of marketed sublease and expiring space signals softening ahead. Per CBI Commercial, availability captures space a tenant could lease now or in the near term, making it the sharper gauge of leverage for anyone negotiating a deal.
For a landlord, a rising availability rate warns of pricing pressure before vacancy confirms it. For a tenant, a high availability rate signals negotiating room even if the building looks full today. The gap between availability and vacancy is itself a read on how much shadow and sublease supply is queued up.
Example
Consider a hypothetical office submarket with 10,000,000 square feet of total rentable inventory. Vacant, empty space totals 800,000 square feet. Another 400,000 square feet is still occupied but being marketed, either because leases are expiring soon or tenants are offering sublease space.
Measure | Space | Rate |
|---|---|---|
Vacancy rate | 800,000 vacant SF divided by 10,000,000 | 8.0% |
Marketed but occupied | 400,000 SF | Added to numerator |
Availability rate | 1,200,000 marketed SF divided by 10,000,000 | 12.0% |
The vacancy rate is 800,000 divided by 10,000,000, or 8.0 percent. The availability rate adds the 400,000 square feet of marketed-but-occupied space, giving 1,200,000 divided by 10,000,000, or 12.0 percent. The 4-point gap is the near-term supply that vacancy alone misses, and it is exactly what a tenant would cite to press for concessions.
Related Terms
Sublease Space
Shadow Space
Absorption
Occupancy Rate