Construction Shell vs Finish Calculator

Shell-and-core vs interior fit-out separates landlord scope from tenant TI.

Total construction cost

Shell share %

Building sq ft

Shell $/sf

$92

Shell cost

$5,500,000

Interior cost

$4,500,000

How the math works

Shell = total × shell share %. Interior = total − shell. $/sf = shell / building sq ft.

$10M × 55% = $5.5M shell, $4.5M interior. $5.5M / 60,000 = $91.67 shell $/sf.

How to Use

Enter total construction cost.
Enter shell share %.
Enter building sq ft.
Read shell $/sf.

Frequently Asked Questions

Shell vs fit-out split?

Office: shell 50–60% of total ($120–200/sf), interior 40–50% ($80–150/sf). Retail: shell 60–70% ($90–160/sf), interior 30–40% ($40–100/sf). Industrial: shell 80–90% ($60–120/sf), minimal interior. Multifamily: shell + finish typically delivered together. Spec build: developer delivers vanilla shell, tenant pays interior. Build-to-suit: developer delivers full ready-to-occupy, lease rate higher, recoups interior cost over lease. Track separately for clear accounting.

How does this impact project budget?

Construction budgets layer hard costs (50–65%), soft costs (15–25%), financing (5–10%), contingency (5–10%), and developer fee (3–5%). Schedule risk often equals or exceeds cost risk — every month delay carries carry cost (interest, real estate tax, insurance, opportunity cost) of 0.5–1.5% of project budget. This calculator quantifies one cost component.

Owner-controlled vs GMP vs CM-at-risk?

Lump sum/GMP: contractor takes risk above guaranteed maximum price, owner pays for change orders. CM-at-risk: open book, fee + GMP, more transparent. Construction management: agent for owner, GC subcontracted directly. Design-build: single accountability, faster but less price competition. Match delivery method to project complexity and owner sophistication.

Schedule and cost contingency?

Standard contingency: 10% of hard cost for entitlement, 5–8% for construction. Schedule contingency: 60–90 days buffer past target completion. Force majeure provisions: weather, material lead time, labor strike, permit delay. Track via critical path method (CPM) schedule. Major lender draws contingent on schedule + cost variance to budget remaining within 5%.