Speculative Development

Speculative development, or a spec build, is the construction of a commercial property without a signed tenant in place, on the expectation that demand will materialize during or after construction. The developer carries full lease-up risk and earns no income until tenants sign, making it the highest-risk posture in ground-up development.

How Does Speculative Development Work?

Speculative development works by building a general-purpose property designed for broad appeal, then leasing it after delivery rather than before. The developer funds land, construction, and carry with equity and construction debt, absorbing all cost during the build, and only begins generating income once the finished space is leased and occupied.

Per NAIOP, spec buildings are designed for a general type of user rather than a specific one, so they are close to what many occupiers need but exactly right for none. That trade-off is deliberate: broad appeal widens the pool of prospective tenants, which is the developer's hedge against having no commitment at the start. The pace at which those tenants sign, the absorption rate, determines whether the pro forma holds.

Why Speculative Development Matters

Speculative development matters because it is how new supply reaches the market ahead of demand, and its returns hinge entirely on lease-up timing rather than a locked commitment. When absorption is fast, spec delivers the highest return of any development posture; when demand misjudges, the developer holds an empty building while debt service and operating carry accrue.

The strategy is procyclical. Per CBRE industrial research, speculative deliveries made up roughly 73 percent of U.S. industrial completions in the first quarter of 2026, up from about 71 percent in 2025, even as CBRE noted spec starts were slowing because of elevated vacancy and tighter construction financing. The same research put first-quarter 2026 industrial vacancy at about 7.0 percent, the kind of level that makes lenders and developers cautious about building without pre-leasing.

Because income is deferred and uncertain, a spec project must underwrite a wider return spread than a pre-committed one. That extra margin is compensation for carrying a finished building with no tenant, the single risk that separates speculative development from the rest of the ground-up strategies.

Example

A developer builds a 100,000-square-foot speculative warehouse for $15,000,000 in total cost, expecting to lease it at $8.00 per square foot net over 12 months. The table compares the base-case lease-up against a slow-absorption case where half the building sits vacant for the first year, at a 7.5 percent annual carry cost on total capital.

In the base case, the fully leased building produces $800,000 of net rent against $1,125,000 of carry, still $325,000 negative in year one before stabilization. If lease-up stalls and only half the space fills, net rent drops to $400,000 while carry stays at $1,125,000, deepening the year-one shortfall to $725,000. The $400,000 swing between the two cases is pure lease-up risk, the exposure a build-to-suit removes by signing a tenant first.

Variations and Edge Cases

Speculative development is not one risk profile: partial pre-leasing, product type, and market timing shift how much lease-up exposure the developer actually carries. The variants below show where the label bends.

Per CBRE, speculative activity concentrates in expansions and thins in downturns, so the same building carries very different risk depending on where in the cycle it delivers. A spec project that breaks ground into rising vacancy faces a longer, more expensive lease-up than one delivering into a supply-constrained market.

Speculative Development vs Build-to-Suit

Speculative development is often confused with build-to-suit, but they differ on one decisive point: whether a tenant is committed before construction. Speculative development builds a generic property with no signed lease, betting demand will arrive. Build-to-suit builds a custom property for a specific tenant who has signed a lease before ground breaks.

The difference is where risk sits. In speculative development the developer holds lease-up and vacancy risk until tenants sign, and per NAIOP designs for broad appeal rather than any one user. In build-to-suit the tenant is identified and locked into a long-term lease, typically 10 to 20 years, so the developer carries little lease-up risk in exchange for a lower, more certain return. Spec chases upside; build-to-suit buys certainty.

Frequently Asked Questions

What is speculative development in commercial real estate?Speculative development, or a spec build, is the construction of a commercial property without a signed tenant in place, on the expectation that demand will materialize during or after construction. The developer carries full lease-up risk and earns no income until tenants sign, making it the highest-risk posture in ground-up development.

What is the difference between speculative development and build-to-suit?Speculative development builds a generic property with no committed tenant, betting demand will arrive, while build-to-suit builds a custom property for a tenant who signs a lease before construction. In speculative development the developer holds lease-up risk; in build-to-suit that risk is largely removed by the pre-committed, typically 10-to-20-year lease.

How common is speculative development in the industrial market?Per CBRE industrial research, speculative deliveries made up roughly 73 percent of U.S. industrial completions in the first quarter of 2026, up from about 71 percent in 2025. CBRE also noted that spec starts were slowing because of elevated vacancy near 7.0 percent and tighter construction financing.

Related Terms

• Build-to-Suit

• Ground-Up Development

• Absorption Rate

• Vacancy Rate

• Net Absorption