Environmental Control Systems Break-Even: $136K Monthly Revenue

Fixed costs $76.7K/mo Year 1 base

Contribution margin 70% After variable costs

Break-even revenue $109.6K/mo Monthly target

Break-even timing Month 6 Launch ramp

Break-even calculator

Test whether monthly revenue covers variable expenses and fixed monthly costs.

Lean Base Full

Monthly revenue Revenue sets the pool left after direct costs to cover overhead. $ Low sales High sales Variable expenses Direct labor, parts, and travel rise with each project. $ Low costs High costs

Money available to cover fixed costs $131,833 $188,333 revenue - $56,500 variable expenses

Margin ratio

70%

Covers fixed costs

Yes

Fixed monthly costs Rent, payroll, software, and other monthly overhead stay in place. $ Lean overhead Heavy overhead

Break-even chart Revenue Total costs

Which expenses stay fixed and which move with sales for an environmental control systems company?

Cost classification

Break-even gets reliable only when fixed overhead is separated from job-linked spend. In the first year, rent stays at $12,500 per month, while equipment procurement moves at 18.5% of revenue.

Expense	Cost	Break-Even Treatment	Common Mistake
Warehouse and Office Rent	Fixed	Use $12,500 per month from Month 1 through Month 60.	Tying rent to project wins instead of capacity.
Professional Liability Insurance	Fixed	Include $2,200 per month before calculating job margin.	Burying it inside project-level profitability.
Software Licenses and ERP	Fixed	Carry $1,200 per month even in slow months.	Dropping it when booked work dips.
Equipment and Hardware Procurement	Variable	Model at 18.5% of first-year revenue, then update by year.	Treating direct hardware spend as overhead.
Field Consumables and Supplies	Variable	Include 4.5% of first-year revenue in contribution margin.	Leaving supplies out of job margin.
Sales Commissions	Variable	Apply 4.0% of revenue to booked sales.	Spreading commissions evenly across months.
Vehicle Fuel and Maintenance	Variable	Use 3.0% of first-year revenue for field activity.	Confusing fuel and maintenance with fleet purchase spend.
Lead Installation Technician Payroll	Semi-fixed	Model salaried crews in FTE steps as installation capacity grows.	Assuming payroll rises smoothly with every job.

How does break-even change from a lean launch to a full buildout?

Scenario table

Lean gets to break-even with the lightest fixed load, but the cushion is slimmer. Base is the clearest balance point, and full only works if maintenance attach, backlog quality, and crew use stay strong.

Planning cases only; actual break-even will move with backlog, contract mix, and crew use.

Scenario	Monthly Revenue	Variable Costs	Fixed Costs	CM Ratio	Operating Profit	Break-Even Signal
Lean launch case	$188.3k	$56.5k	$95.2k	70.0%	$36.7k	Month 6 break-even is met, but cushion is thin.
Base buildout case	$459.1k	$121.9k	$150.3k	73.5%	$186.9k	Higher maintenance mix improves coverage, but crew use still matters.
Full scale case	$652.3k	$156.6k	$201.9k	76.0%	$293.8k	Best cushion here, if backlog and install flow stay steady.

What pushes the Month 6 break-even plan off track?

Stress test

Year 1 average revenue is about $188.3k/month against a $136k break-even. At roughly 70% contribution margin, every $10k of lost sales below break-even cuts operating profit by about $7k, so the cushion can disappear quickly.

Stress Case	Changed Assumption	Break-Even Revenue	Revenue Gap	Risk Signal
Current plan	No change.	$136k	$52.3k cushion	Year 1 revenue clears break-even, but not by a wide margin.
Revenue shortfall	Monthly revenue falls 30% from the Year 1 average.	$136k	$4.2k gap	A modest sales miss pushes the plan below break-even.
Fixed-cost increase	Monthly fixed overhead rises 15%.	$156.4k	$31.9k cushion	Rent, insurance, software, and staffing leave less room fast.
Margin pressure	Contribution margin slips from 70% to 62%.	$153.5k	$34.8k cushion	Supplier spikes and rework make each job contribute less.
Combined pressure	Revenue falls 20%, fixed overhead rises 15%, and margin slips to 62%.	$176.6k	$25.9k gap	The Month 6 break-even plan turns into a cash drain.

Can this environmental control systems business carry the lease, payroll, and fleet before you commit?

Founder checklist

Don’t lock rent, payroll, vehicles, or inventory until the model can carry Month 6 cash needs and the $136k monthly break-even floor. If signed work, marketing, and capacity can’t support that load, the fixed base is too heavy.

1Pipeline Cost$120k / $8.5k CAC

Verify the Year 1 marketing budget can hold customer acquisition cost (CAC) near $8.5k per customer, because demand must be affordable before you lock fixed overhead.

2Fixed Base$76.7k/mo

Check that Year 1 payroll of $655k plus $22.2k of monthly nonpayroll overhead stays near plan, because that fixed load is what the lease and staff must support.

3Break-even Floor$136k/mo

Use the $136k monthly break-even floor as the go/no-go line; if signed work cannot clear it, the mix still needs more contribution after equipment, supplies, commissions, and fuel.

4Install Capacity160 hrs

Make sure system installation can support 160 billable hours at $185/hour, or about $29.6k of monthly work, before you add more crews.

5Recurring Mix40% / 20%

Confirm Year 1 maintenance contracts reach 40% attach and IAQ auditing reaches 20%, because recurring work is what steadies field utilization after installs.

6Launch Cash$422k / $399k

Keep launch capex at the $422k plan and hold the $399k Month 6 cash cushion, or the rollout can run short before payback.