Sunroom Addition Break-Even Analysis: About $83K/Month

Fixed costs $55.3K/mo Salaried overhead base

Contribution margin 71% After variable costs

Break-even revenue $77.9K/mo Monthly revenue target

Break-even timing Month 2 Launch month

Break-even calculator

Use this calculator to test monthly revenue, direct costs, and fixed costs against break-even.

Lean Base Full

Monthly revenue Sales set the margin left to cover fixed costs. $ Lower sales Higher sales Variable expenses Direct materials, labor, commissions, and permit costs rise with each project. $ Lower costs Higher costs

Money available to cover fixed costs $1,557,548 $2,122,000 revenue - $564,452 variable expenses

Margin ratio

73%

Covers fixed costs

Yes

Fixed monthly costs This monthly cost base must be covered before profit starts. $ Lean setup Heavier setup

Break-even chart Revenue Total costs

Which expenses are fixed and which move with sales in a sunroom addition business?

Cost classification

Break-even is only useful if each expense behaves the way the model says it does. Misclassifying materials, permits, or commissions as fixed can make Month 2 break-even look safer than it really is.

Expense	Cost	Break-Even Treatment	Common Mistake
Showroom and Office Rent	Fixed	Include $6,500 per month in fixed overhead from Month 1 through Month 60.	Spreading rent across jobs and hiding the monthly burden.
Insurance General Liability and Workers Comp	Fixed	Include $2,200 per month as a fixed operating expense in the break-even base.	Treating insurance as job-level labor expense.
Raw Materials and Framing Components	Variable	Apply 14% of revenue in the first year, then use the lower annual rates shown in the model.	Treating materials as fixed and overstating contribution margin.
Subcontracted Specialist Labor	Variable	Apply 10% of revenue in the first year, with the modeled decline through the mature year.	Ignoring subcontractor load when job mix gets heavier.
Sales Commissions and Incentives	Variable	Apply 3% of revenue because commissions rise directly with sold projects.	Budgeting commissions as a flat monthly sales expense.
Project Permitting and Compliance Fees	Variable	Apply 2% of revenue in the first year, then follow the model’s lower annual rates.	Holding permit fees flat even as project count changes.
Vehicle Lease and Fuel Expenses	Semi-variable	Start with the $3,800 monthly base, but review job usage because trucks carry both lease burden and site-driven fuel use.	Calling the full truck expense fixed during volume spikes.
Construction Crew Lead payroll	Semi-fixed	Model payroll in staffing steps because crew leads rise from 2.0 FTE in the first year to 6.0 FTE in Year 5.	Assuming labor leadership scales smoothly with every dollar of revenue.

How does break-even shift from a lean startup floor to Year 1 and Year 5 volume?

Scenario table

Here’s the quick math: fixed payroll and overhead set the floor, and the job mix changes how fast revenue clears it. The lean case barely covers costs, Year 1 is far above break-even, and Year 5 has the widest cushion.

Planning assumptions only; permit timing, deposits, and crew scheduling can move cash before profit shows up.

Scenario	Monthly Revenue	Variable Costs	Fixed Costs	CM Ratio	Operating Profit	Break-Even Signal
Lean startup floor	$83k	$24k	$59k	71%	$0	Right at break-even, so a delay can flip profit negative.
Year 1 steady flow	$778k	$226k	$59k	71%	$493k	About $695k above break-even, so normal timing gaps are absorbable.
Year 5 full schedule	$3,385k	$819k	$114k	75.8%	$2,452k	Biggest cushion, but the higher fixed-cost floor still matters.

What breaks the break-even plan for a sunroom addition contractor?

Stress test

Year 1 average monthly revenue of about $778K versus $83K break-even leaves about $695K cushion. The main risk is not the base case; it’s weaker signed backlog, a payroll step-up, or a few points of margin loss on glass, framing, and subcontracted labor.

Stress Case	Changed Assumption	Break-Even Revenue	Revenue Gap	Risk Signal
Current plan	No change.	$83K	$695K cushion	Base case clears break-even fast.
Revenue shortfall	Booked revenue runs $100K below the Year 1 monthly average.	$83K	$595K cushion	A smaller sales month still clears break-even, but the cushion shrinks fast.
Fixed-cost pressure	Add one Construction Crew Lead at a $75K annual salary.	$92K	$686K cushion	Payroll only works if the project calendar stays full.
Margin pressure	Variable expenses rise 1 point on materials, subcontracting, or permits.	$84K	$694K cushion	A 1-point margin slip can erase about $78K of monthly contribution at Year 1 revenue.
Combined pressure	Booked revenue drops $100K per month, one Crew Lead is added, and variable expenses rise 1 point.	$94K	$584K cushion	Unsigned backlog, permit delays, and idle crews stack the downside.

What should you verify before you commit to trucks, tools, and ad spend for a sunroom addition contractor?

Founder checklist

Before you buy trucks, tools, and buildout assets, make sure the lead flow, pricing, and crew math still support break-even. This model reaches break-even in Month 2, but minimum cash still dips to $748,000 in Month 2, so the launch has to start tight.

1Lead flow$1,500 CAC

Customer acquisition cost (CAC) is what you spend to win one customer, so test real inquiries before you commit the $45,000 Year 1 marketing budget.

2Margin math71% CM

Contribution margin means cash left after direct costs, and Year 1 direct costs run 29% of revenue, so keep framing, glazing, labor, commissions, and permitting inside that spread.

3Fixed load$55.3K/mo

Check that monthly overhead stays near the model before adding lease or payroll; fixed expenses plus Year 1 salaries total about $55,250 a month.

4Job rulesBefore deposits

Lock deposit timing, change-order terms, warranty reserve logic, insurance, workers comp, and handoff rules so rework does not eat the job margin.

5Crew hours160/220/350 hrs

Match crew and subcontractor coverage to 160, 220, and 350 billable hours by product so the schedule can absorb each build.

6Launch stack$195.5K

Stage the $195,500 launch stack in order and confirm permit steps by city or county before you take deposits or spend on trucks, tools, IT, and buildout.