Commercial Tenant Improvements in Contra Costa County: Costs, TI Allowances, and Timelines

Tenant improvement build-outs in California commonly run $50 to $250 per square foot, and the landlord's TI allowance rarely covers all of it. Here is how the money and the timeline actually work.

Signing a commercial lease is the easy part. Turning an empty shell - or somebody else's old floor plan - into a space where your business can operate is where budgets and opening dates go to die. That process is called a tenant improvement (TI), and how well it goes depends on decisions you make before the lease is even signed.

Otto & Sons Construction is a licensed California general contractor (CSLB #1104751) based in Antioch. Commercial tenant improvements are one of our core services across Contra Costa County and the Bay Area - office build-outs, retail improvements, restaurant work, and warehouse and light-industrial TI. This guide explains how TI costs and allowances actually work in 2026.

What tenant improvements cost in 2026

Statewide, TI construction in California commonly runs $50 to $250 per square foot, and the spread by space type is wide:

• Office: roughly $50–180 per square foot. Open plans with existing HVAC at the low end; full buildouts with private offices, conference rooms, and new mechanical at the high end.
• Retail: roughly $40–300 per square foot, driven by storefront work, finishes, and whether the space is first-generation (never built out) or second-generation (reusing a previous tenant's improvements).
• Restaurant: the most expensive category, commonly $200+ per square foot - commercial kitchens, hoods, grease interceptors, and health-department requirements stack quickly.
• Warehouse / light industrial: often the most economical, when the scope is offices-within-a-shell, ADA restrooms, and code compliance rather than full finishes.

The first-generation vs. second-generation distinction matters more than any other single factor. A second-generation space that mostly fits your layout can cost a fraction of a raw shell.

How TI allowances actually work

A tenant improvement allowance (TIA) is the landlord's contribution to your build-out, negotiated in the lease and quoted per square foot. In this market, office allowances commonly range from $10 to $100 per square foot depending on lease length, tenant credit, and how badly the landlord wants the space filled; premium Bay Area office space can go higher.

Three things tenants routinely learn the hard way:

1. It is a reimbursement cap, not a check. You typically pay the contractor and submit documentation; the landlord reimburses up to the cap. Your cash flow carries the project.
2. The allowance rarely covers the full build-out. The gap between allowance and actual cost is yours. Knowing that gap *before* signing is exactly why you bring a contractor into the deal early.
3. Everything is negotiable with the term. Longer leases justify bigger allowances. If the allowance is fixed, negotiate free rent during the construction period instead.

Who manages the work: three structures

• Tenant-controlled (most common with an allowance): you hire the general contractor, control scope and schedule, and the landlord reimburses. Most protective of your interests.
• Turnkey (landlord builds): the landlord's contractor builds to an agreed plan. Simple, but you lose cost transparency and change control.
• Landlord-managed with tenant funds: generally the worst of both; avoid when possible.

If you control the build, your general contractor becomes your schedule advocate - and in Contra Costa County, local permit familiarity is worth real calendar time.

The permit reality in Contra Costa County

Commercial TI permits are more involved than residential ones: plan check covers accessibility (ADA/CBC Chapter 11B), egress, fire-rated assemblies, mechanical and electrical loads, and - for food service - county environmental health on top of the building department. Each city in the county (Antioch, Concord, Walnut Creek, Pittsburg, Brentwood and the rest) runs its own building division; unincorporated parcels go through the county.

Two schedule protectors:

• Submit complete drawings. Most TI plan-check delay is correction cycles from incomplete mechanical/electrical/plumbing sheets, not slow reviewers.
• Sequence long-lead items early. HVAC units, storefront glass, electrical switchgear, and custom millwork have lead times that can exceed the construction schedule itself. We order them at permit submittal, not at permit issuance.

What blows up TI schedules (and how to prevent it)

1. Signing the lease before pricing the build. Get a contractor's budget number on the space *during* lease negotiation - it is your leverage on the allowance.
2. ADA surprises in older buildings. Restroom compliance and path-of-travel upgrades can be triggered by your project even in areas you are not touching. Budget for them in due diligence, not mid-build.
3. Utility capacity. Older Contra Costa retail and industrial stock often lacks the electrical service a modern use needs. A service upgrade involves the utility's timeline, which no contractor controls - find out early.
4. Opening-date compression. Rent commencement is usually tied to a fixed date, not to your build being done. Every week of slip is a week of paying rent on a space that earns nothing.

How Otto & Sons runs a TI project

• Pre-lease budgeting: walk the space with us before you sign; you negotiate the allowance with a real number in hand.
• Fixed scope and a construction calendar tied to your rent commencement date.
• Permits and inspections handled - building, fire, accessibility, and health where applicable.
• Direct communication: you deal with Otto, not a project-manager relay. If the schedule moves, you hear it from us first, with the recovery plan.

Related reading

• How to Verify a California Contractor License Before You Hire
• Our commercial construction services