Why Curtain Wall Contractors Fund the Mock-Up for Free

QUICK ANSWER

Curtain wall contractors fund engineering and performance mock-ups for free when those costs have no schedule of values line, then wait on sequential installation to bill panels that were fabricated months earlier. CONTROL gives engineering and mock-ups their own billing milestones and funds fabrication ahead of the field sequence.

BY JOSH LUEBKER · UPDATED JUL 2026 · COMING SOON

Panel-Based Billing

Panels fabricate in batches and install in sequence. Billing tied only to installed panels starves the fabrication months where most of the cost happens.

Engineering and Mock-Up Cost Allocation

Design assist, engineering, and performance mock-ups cost serious money before any panel exists. Their own SOV lines make them fundable milestones instead of overhead.

Sequential Installation Cash Holes

Floor-by-floor installation means revenue meters out slowly against material bought in bulk. A 13-week forecast shows where the sequence starves the account.

THE FIX

The CONTROL chapters that solve this for curtain wall contractors specifically.

CHAPTER 6

Project Management Standards

SOV lines for engineering, mock-ups, and stored panels.

CHAPTER 1

Job Cost Structure

Cost codes that follow panels from shop to elevation.

CHAPTER 7

Monthly Cadence

A forecast built for long fabrication-to-install cycles.

RELATED READING

QUESTIONS CURTAIN WALL CONTRACTORS ASK

Why do curtain wall contractors lose money before installation begins?

Curtain wall contractors lose money before installation because engineering, design assist, and performance mock-ups consume months of cost with no revenue against them. When those scopes lack schedule of values lines, the contractor funds the project's riskiest phase for free and hopes the panel billing eventually catches up.

How should a curtain wall contractor structure billing?

A curtain wall contractor should build the schedule of values around milestones it controls: engineering complete, mock-up passed, panels fabricated and stored, panels installed. Chapter 6 of CONTROL structures that SOV, so fabrication months generate pay applications instead of waiting on the tower crane.

What profit margin should a curtain wall contractor target?

A curtain wall contractor should target 22 to 30% gross profit per project and 12% net profit after all expenses, with overhead between 9 and 13%. On long-cycle work, the cash forecast decides survival, because the margin only pays out if the company is still solvent when the last panel sets.

JOSH LUEBKER

PRESIDENT · SPM THE CONSTRUCTION CFO

Josh Luebker is a former commercial construction project manager and master electrician. He has managed 150+ projects totaling $2.1B+, including Google data centers, military bases, hospitals, and high-rises. CONTROL is built on what works in the field.

Josh leads SPM The Construction CFO (Sulphur Prairie Management, LLC), the fractional CFO for commercial subcontractors.

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Why Curtain Wall Contractors Fund the Mock-Up for Free

Panel-Based Billing

Engineering and Mock-Up Cost Allocation

Sequential Installation Cash Holes

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