Waterside Economizer Break-Even Analysis: $77K Monthly Target

Fixed costs $14.9K/mo Lease and admin base

Contribution margin 71% After variable costs

Break-even revenue $21.0K/mo Monthly sales target

Break-even timing Month 7 Startup ramp period

Break-even calculator

Test monthly revenue against variable expenses and fixed overhead to see when the project breaks even.

Lean Base Full

Monthly revenue Revenue sets the margin pool that covers overhead. $ Low sales High sales Variable expenses These are direct costs that rise with project volume. $ Lean spend Heavy spend

Money available to cover fixed costs $205,003 $278,917 revenue - $73,914 variable expenses

Margin ratio

73%

Covers fixed costs

Yes

Fixed monthly costs These costs stay on the books each month. $ Tight overhead Heavy overhead

Break-even chart Revenue Total costs

Which waterside economizer installation expenses are fixed, and which move with sales?

Cost classification

Break-even gets sloppy when monthly capacity expenses are mixed with job-linked expenses. Keep recurring overhead, payroll steps, and revenue-based costs separate so Month 7 break-even is based on the right inputs.

Expense	Cost	Break-Even Treatment	Common Mistake
Warehouse and Office Lease	Fixed	Include $7,500 per month in fixed overhead.	Tying rent to job count instead of capacity.
Professional Liability Insurance	Fixed	Include $1,450 per month below gross margin.	Burying insurance inside variable project margin.
Vehicle Fleet Leasing and Maintenance	Semi-fixed	Use $3,200 per month until fleet capacity expands.	Spreading fleet expense as a percent of revenue.
Equipment and Component Procurement	Variable	Apply 14.5% of first-year revenue to project costs.	Modeling parts as fixed because purchases are lumpy.
Subcontracted Specialty Labor	Variable	Apply 8.0% of first-year revenue to job delivery.	Treating subcontract labor like salaried staff.
Project Logistics and Freight	Variable	Apply 3.5% of first-year revenue to field delivery.	Ignoring freight until large installations hit cash flow.
Sales Commissions and Incentives	Variable	Apply 3.0% of revenue as sales volume scales.	Putting commissions in fixed payroll.
Payroll Roles	Semi-fixed	Use $432,000 in first-year salaries, then add headcount in steps.	Assuming payroll moves smoothly with each project.

How does break-even change from lean backlog months to full retrofit months?

Scenario table

As project volume climbs, fixed overhead gets spread across more revenue, so break-even rises in dollar terms but becomes easier to clear. The lean case is tight, the base case has room, and the full case needs steady commercial retrofit demand.

Planning case only; actual results will move with close rates, crew mix, and project timing.

Scenario	Monthly Revenue	Variable Costs	Fixed Costs	CM Ratio	Operating Profit	Break-Even Signal
Lean backlog month	$96,000	$27,840	$54,650	71.0%	$13,510	Just above break-even, with a thin cushion.
Base operating month	$279,000	$73,935	$87,567	73.5%	$117,498	Clear break-even coverage and solid overhead spread.
Full retrofit month	$534,000	$128,160	$128,400	76.0%	$277,440	Strong cushion, but only if demand stays steady.

What breaks first if revenue slips or costs climb in this installation business?

Stress test

Base-year cash flow has room, but not much. A 15% revenue drop leaves only about $3.4k cushion, and 10% higher fixed costs or 34% variable costs push break-even into the low-to-mid $80k range; combined pressure flips to about a $6.2k monthly loss.

Stress Case	Changed Assumption	Break-Even Revenue	Revenue Gap	Risk Signal
Current plan	No change.	$77,000	$13,500 cushion	The plan clears break-even, but the buffer is not wide.
Revenue shortfall	Revenue falls 15% to about $81,700.	$77,000	$3,400 cushion	A small drop in wins cuts the cushion fast.
Fixed-cost increase	Fixed costs rise 10% to about $60,100.	$84,600	$7,800 cushion	Overhead creep raises the break-even hurdle.
Margin pressure	Variable costs rise to 34% of revenue.	$82,800	$8,700 cushion	Freight, rework, and overtime squeeze profit.
Combined pressure	Revenue falls 15%, variable costs rise to 34%, and fixed costs rise 10%.	$91,100	$6,200 gap	That mix turns the month negative quickly.

What should you verify before you lock in the lease, vans, and first hires?

Founder checklist

Before you sign long-term commitments, make sure the backlog, margin, and cash all support Month 7 break-even. This model only works if early work is real, because Year 1 payroll reaches $432K and cash bottoms at $631K.

1Signed backlog$432K payroll

Verify signed or near-signed work can support the Year 1 payroll load before you lock in long-term commitments.

2Monthly burn$50.9K/mo

Add the $14.9K monthly overhead to Year 1 payroll and confirm the pipeline can cover about $50.9K of fixed burn each month.

3Margin mix71.0% CM

Check that quoted jobs hold a 71.0% contribution margin after 14.5% equipment, 8.0% subcontracted labor, 3.5% freight, and 3.0% sales incentives.

4Crew ramp4.0 FTE

Make sure 4.0 FTE can handle commissioning, installs, and sales now, because the model adds an operations coordinator in Month 13 and a junior field tech in Month 25.

5Cash floor$631K

Protect at least $631K of cash through Month 7, since that is the model’s low point before breakeven.

6CAC test$3.5K CAC

Use the $45K Year 1 marketing budget to keep CAC near $3,500; if acquisition cost runs higher, the path to breakeven stretches out.