Whole House Fan Installation Break-Even: About $41K/Month

Fixed costs $28.5K/mo Monthly overhead base

Contribution margin 70% After variable costs

Break-even revenue $40.7K/mo Revenue needed monthly

Break-even timing Month 7 First break-even point

Break-even calculator

Use this calculator to test whether monthly revenue covers variable expenses and fixed monthly costs.

Lean Base Full

Monthly revenue Revenue sets the pool available to cover overhead and profit. $ Slow month Busy month Variable expenses Direct costs rise with each install, visit, and referral. $ Tighter costs Higher costs

Money available to cover fixed costs $27,492 $48,750 revenue - $21,258 variable expenses

Margin ratio

56%

Covers fixed costs

Yes

Fixed monthly costs This is the monthly overhead contribution margin must cover. $ Lower overhead Higher overhead

Break-even chart Revenue Total costs

Which expenses are fixed and which move with whole house fan installation sales?

Cost classification

Classify costs by what changes when installs change. In this model, revenue first covers about $28,500 of monthly overhead, then a 30% revenue load for inventory, consumables, fuel, and referral commissions.

Expense	Cost	Break-Even Treatment	Common Mistake
Warehouse and Office Rent	Fixed	Include in the $28,500 monthly overhead from Month 1.	Spreading rent across installs and hiding the base monthly hurdle.
General Liability Insurance	Fixed	Include in the $28,500 monthly overhead; it does not rise with each job.	Treating insurance as a per-install charge instead of a monthly obligation.
CRM and Scheduling Software	Fixed	Include in the $28,500 monthly overhead for break-even planning.	Leaving software out because the monthly amount looks small.
Payroll	Semi-fixed	Include first-year staffing in the $28,500 monthly overhead, then step it up when FTEs increase.	Assuming labor scales smoothly instead of jumping when another technician is hired.
Equipment and Fan Inventory	Variable	Include in the 30% revenue load; first-year inventory is 18% of revenue.	Booking inventory as fixed overhead and overstating margin on each install.
Installation Consumables	Variable	Include in the 30% revenue load; first-year consumables are 4% of revenue.	Ignoring small materials that rise with every completed installation.
Vehicle Fuel and Maintenance	Semi-variable	Include in the 30% revenue load; first-year fuel and maintenance are 5% of revenue.	Treating fuel and rework trips as fixed when job count drives usage.
Lead Referral Commissions	Variable	Include in the 30% revenue load; first-year commissions are 3% of revenue.	Forgetting commissions when referral-driven jobs increase.

How does break-even change across lean, base, and strong-demand months for whole house fan installation?

Scenario table

A base month clears break-even, but a lean month does not. With about $28.5k in fixed costs, the line sits near $40.7k in monthly revenue, so seasonality, attic access, electrical scope, and pricing can flip the result.

Planning assumptions only; seasonality, attic access, electrical scope, and pricing can move actual results.

Scenario	Monthly Revenue	Variable Costs	Fixed Costs	CM Ratio	Operating Profit	Break-Even Signal
Lean install month	$36,000	$10,800	$28,500	70%	-$3,300	Below the ~$40.7k line, so one soft month loses money.
Year 1 average month	$48,750	$14,625	$28,500	70%	$5,625	Covers fixed costs with a small cushion, but delays can wipe it out.
Strong-demand month	$60,000	$15,000	$28,500	75%	$16,500	Higher mix and better efficiency build a safer cushion above break-even.

What breaks the break-even plan for this whole house fan installer?

Stress test

The base plan clears break-even by about $8,000 a month, but the cushion is thin. Slower lead flow, higher job costs, or extra fixed overhead can turn a launch month into a cash drain fast.

Stress Case	Changed Assumption	Break-Even Revenue	Revenue Gap	Risk Signal
Current plan	No change.	$40,714	$8,036 cushion	This clears break-even, but the buffer is only about $8,000.
Revenue shortfall	Monthly revenue falls 20% to $39,000 from slower lead flow and seasonality.	$40,714	$1,714 gap	Slow lead flow, seasonality, or discounting can push the month below break-even.
Fixed-cost increase	Fixed monthly costs rise 20% to $34,200 from added staff and overhead.	$48,857	$107 gap	More hiring or overhead can erase the cushion almost completely.
Margin pressure	Variable expenses rise to 42% of revenue from fuel, inventory, consumables, referral fees, and rework.	$49,138	$388 gap	Rework, fuel, consumables, and referral fees can flip a normal month negative.
Combined pressure	Revenue falls 20%, fixed costs rise 20%, and variable expenses rise to 42%.	$58,966	$19,966 gap	Lower installs plus higher job costs create a real cash drain.

Can you prove enough booked demand and crew capacity before you lock in the van, lease, and hires?

Founder checklist

Test the pipeline, home fit, and cash runway before you add fixed spend. If booked leads, screening, and crew capacity do not line up with the $40,700 monthly break-even point, hold the lease and hiring plan.

1Demand proof$450 CAC

Verify booked leads at the Year 1 customer acquisition cost against the $45,000 marketing budget, or the install pipeline will not support break-even.

2Access screen4 checks

Screen each home for attic access, ventilation path, electrical scope, and permit need before quoting, because bad-fit jobs burn hours and margin.

3Fixed load$6.2K/mo

Keep the monthly base load for rent, insurance, software, utilities, licensing, and the equipment lease in line before adding more overhead near the $40,700 break-even point.

4Crew ramp3.5 FTE

Verify that the opening crew plus subcontractor electrician coverage can handle one van, tool kits, ladders, and safety gear without idle time or missed installs.

5Cash cushion$790K min

Hold the Month 2 minimum cash need before buying the van, tools, storage, and computers, so early spending does not outrun the ramp.

6Break-even timingMonth 7

Do not add extra staff or warehouse scale until bookings can carry you to the Month 7 break-even point and keep seasonal capacity full.