Tenant Improvement vs Shell Build-Out Decision

Two terms come up constantly in NE Florida commercial construction: tenant improvement (TI) and shell build-out. They mean different things, cost different amounts, and have different permit and timeline implications. Understanding which one applies to your project is the first step in scoping it correctly.

What each one means

Shell build-out. The construction of the building's exterior envelope and base systems — exterior walls, roof, floor slab, basic mechanical (rooftop HVAC unit), basic electrical (panel and meter), basic plumbing (capped supply and waste lines), and demising walls to neighboring tenants. The result is a "vanilla box" or "shell" that's ready for a tenant's interior fit-out.

Tenant improvement (TI). The interior fit-out of the shell — flooring, walls, ceiling, lighting, paint, plumbing trim, electrical for tenant equipment, branded fixtures, finishes. Everything inside the shell that makes it usable for the tenant's specific business.

A retail or restaurant or office space goes through both phases — shell first (developer scope), TI second (tenant scope). The two phases are commonly separated by months or years.

Cost differences

For a 3,000 sqft commercial space:

Shell build-out: $80 to $180 per sqft (depending on building type, location, code requirements). $240,000 to $540,000.

Standard tenant improvement: $80 to $180 per sqft (depending on tenant use). $240,000 to $540,000.

Combined shell + TI: $160 to $360 per sqft total. $480,000 to $1,080,000.

For comparison: full ground-up new commercial construction typically runs $200 to $500 per sqft, depending on use and finish level — meaning shell + TI is comparable to or somewhat below ground-up new construction.

When each applies

Shell build-out scenarios:

New commercial development (strip center, office park, industrial building)
Existing building substantial reconstruction
Demising existing larger space into multiple tenant suites

TI scenarios:

Tenant moving into vanilla box space
Tenant renewing or expanding within existing leased space
Change of use within existing TI'd space
Refreshing existing TI for new tenant

Combined scopes:

Owner-occupied commercial construction (restaurant owner building their own building)
Single-tenant build-to-suit projects
Conversion of one large space to multiple tenant suites

What each scope includes

Shell build-out includes (typically):

Foundation and slab
Structural framing (steel, masonry, or wood)
Exterior walls (insulated, weatherized)
Roof (membrane or metal)
Demising walls to other tenants (basic)
Basic mechanical: rooftop HVAC unit (RTU) sized for typical use, basic ductwork
Basic electrical: meter, panel, conduit to TI areas, parking lot lighting
Basic plumbing: water and sewer to building, capped lines to tenant areas
Restrooms (in some cases)
Code-required exits and life safety

Shell build-out does NOT include (typically):

Interior partitions beyond demising walls
Interior finishes (flooring, paint, ceiling tile)
Tenant-specific lighting trim
Tenant-specific equipment electrical
Tenant-specific plumbing trim
Brand-specific fixtures

TI includes (typically):

Interior partitions and demising
All interior finishes (flooring, walls, paint, ceiling)
Lighting trim and tenant-specific lighting
Tenant-specific equipment electrical
Tenant-specific plumbing trim
Restroom upgrades (if not in shell)
Brand-specific fixtures and millwork
POS infrastructure
Code-required ADA upgrades for the altered space

TI does NOT include (typically):

Building shell modifications (cutting new openings in exterior walls, roof modifications)
Major mechanical upgrades (RTU replacement, exterior ductwork)
Major electrical upgrades (service or panel upgrade)
Major plumbing upgrades (new water service, new sewer connection)

When TI scope requires shell modifications, the project becomes a hybrid that's permitted and contracted as combined work.

Decision framework

Three questions determine which scope applies:

1. Does the project require modifying the building shell? If yes (cutting new wall openings, modifying roof, upgrading shell utilities), the project is hybrid and needs shell-trade involvement.

2. Is the work within an existing TI'd space? If yes, it's a refresh or change-of-use TI project, scope-limited to interior work.

3. Is the building empty shell or vanilla box? If yes, the project is a new TI build-out.

Permit differences

Shell permits. Reviewed as new commercial construction or substantial renovation. Plan review timeline: 8 to 16 weeks. Multi-discipline review (building, fire, mechanical, electrical, plumbing, civil if site work).

TI permits. Reviewed as commercial alteration. Plan review timeline: 4 to 9 weeks (less complex than shell). May still require all five trade permits if scope includes work in each.

Hybrid permits. Combine shell modification with TI scope. Plan review timeline depends on complexity but generally 6 to 12 weeks.

Lease language matters

Commercial leases vary substantially in how they handle the TI vs. shell distinction:

Triple-net (NNN) leases. Tenant typically responsible for all TI cost; landlord delivers shell only. Standard for retail and restaurant.

Modified gross or full-service leases. Landlord may deliver some TI components (basic flooring, paint, restroom). More common for office.

Build-to-suit leases. Landlord delivers fully-built space tailored to tenant requirements. Higher rent in exchange for lower or zero tenant TI obligation.

Tenant Improvement Allowance (TIA). Most leases include a TIA that landlord contributes toward TI cost. Typical Jacksonville retail TIA: $20-60 per sqft. Premium markets: higher.

Verify the lease's TI obligations and TIA structure before scoping the project.

Common confusion points

Three patterns Mark sees regularly:

1. Tenant assumes shell includes more than it does. Tenant signs lease for "vanilla box" space, then discovers they need to install demising walls, restrooms, or HVAC distribution at their cost.

2. Landlord delivery quality lower than expected. Shell delivered with builder-grade materials, exposed conduit, and rough finishes that exceed tenant TI scope to bring up to standard.

3. TI scope creep into shell modifications. Tenant's planned TI requires cutting new exterior wall openings, which becomes shell modification work that the lease may or may not allow.

The fix for all three is a thorough pre-lease walkthrough with a contractor who can identify what's actually delivered and what's actually required for the planned use.

Tenant Improvement vs Shell Build-Out: Which Scope Fits Your NE Florida Project?