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10.3 Job Costing, Break-Even Analysis & Cash Flow Forecasting
Alabama HVAC Contractor License Exam
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1 Alabama HACR Laws, Rules & Licensing
1.1 Alabama HACR Board Authority, Licensing Pathways & Experience Requirements 1.2 Contractor Bonding, Insurance, Fees & Annual Renewal 1.3 Permits, Local Jurisdictions, Inspections & Disciplinary Actions
2 Contractor Business, Contracts, Estimating & Alabama Lien Law
2.1 Business Organization, Risk Management & Project Administration 2.2 Construction Contracts, Change Orders & Warranties 2.3 Alabama Mechanics' Lien Law & Financial Management 2.4 Construction Estimating, Markup & Bid Preparation 2.5 Project Management, Scheduling & Field Supervision 2.6 Risk Management, Contractor Insurance & Surety Bonds
3 Safety Standards, OSHA & EPA Section 608
3.1 OSHA Construction Safety (29 CFR 1926) for HVAC Contractors 3.2 EPA Section 608 Refrigerant Regulations & Recovery Requirements 3.3 Refrigerant Management, Leak Repair Rules & A2L Transition
4 General Technical Knowledge & Thermodynamics
4.1 Principles of Heat Transfer, Temperature & Pressure 4.2 The Mechanical Refrigeration Cycle & Refrigerant Properties 4.3 Psychrometrics & Air Properties for Humid Climates 4.4 Basic Electricity, Ohm's Law & Electrical Power for HVAC
5 Piping Systems, Refrigerant Lines & Fuel Gas Piping
5.1 Refrigerant Piping Sizing, Materials & Installation 5.2 Fuel Gas Piping Sizing & Installation (IRC Chapter 24) 5.3 Condensate Drain Systems & Trapping
6 System Sizing & ACCA Manual J Load Calculations
6.1 ACCA Manual J Fundamentals & Design Conditions 6.2 Envelope Loads: Conduction, Radiation & Fenestration 6.3 Infiltration, Ventilation & Internal Heat Gains
7 Duct System Design & ACCA Manual D
7.1 Airflow Principles, Static Pressure & Fan Performance 7.2 ACCA Manual D Duct Sizing & Friction Rate 7.3 Duct Materials, Installation Standards & Air Distribution
8 Heating & Cooling Equipment Operation
8.1 Heat Pump Systems & Supplemental Heating 8.2 Gas Furnaces & Combustion Systems 8.3 Air Conditioning Units, Compressors & Metering Devices
9 Mechanical Codes, Electrical Applications & Maintenance Diagnostics
9.1 Combustion Air & Venting Systems (IRC Chapter 24) 9.2 Electrical Applications for HVAC (NFPA 70 / NEC Article 440) 9.3 Preventative Maintenance, Troubleshooting & Plan Reading
10 Employment Law, Payroll Taxes & Contractor Finance
10.1 Federal & Alabama Labor Laws for HVAC Employers 10.2 Payroll, Employment Taxes & Worker Classification 10.3 Job Costing, Break-Even Analysis & Cash Flow Forecasting
11 Preventative Maintenance, Service Procedures & Commissioning
11.1 Preventative Maintenance Programs & Service Agreements 11.2 Filter, Coil & Drain Maintenance for Alabama's Humid Climate 11.3 Evacuation, Dehydration & Refrigerant Charging Procedures 11.4 Airflow Verification, Static Pressure Testing & Commissioning
12 Electrical Applications & Construction Documents
12.1 Electric Motors, Compressors & Motor Protection 12.2 Transformers, Control Circuits & Low-Voltage Wiring 12.3 Branch Circuits, Conductors, Grounding & Disconnects 12.4 Construction Documents, Specifications & Submittals
10.3 Job Costing, Break-Even Analysis & Cash Flow Forecasting
Key Takeaways Explain This Topic AI
Break-even revenue equals fixed overhead divided by the gross margin percentage, so a company with $240,000 of overhead running a 30 percent margin must sell $800,000 to break even.
Job costing compares actual cost to estimated cost while the job is running; a variance found at 30 percent complete can still be recovered, one found at closeout cannot.
A work-in-progress schedule reveals overbilling and underbilling; underbilling is the classic early warning that a contractor is financing the owner and heading for a cash crisis.
Profit is an accounting result and cash is a bank balance; a profitable contractor can still fail because retainage, slow receivables, and material deposits consume cash faster than jobs generate it.
Under the Alabama Prompt Pay Act, Code of Alabama Section 8-29-3, retainage withheld by an owner may not exceed 10 percent, no further retainage may be withheld after the project is 50 percent complete, and the percentage may never increase as it flows down to subcontractors.
Last updated: September 2026
10.3 Job Costing, Break-Even Analysis & Cash Flow Forecasting
Important
Profit is an opinion; cash is a fact. More Alabama mechanical contractors fail while showing a profit than while showing a loss. This section builds the three operating tools that prevent it: job costing, break-even analysis, and a rolling cash forecast.
Job Costing: Comparing Actual to Estimate While You Can Still Act
A job cost system assigns every dollar and every hour to a cost code inside a job number.
- Cost code Captures
- 01 Equipment Condensing units, air handlers, furnaces, curbs
- 02 Sheet metal Duct, fittings, hangers, sealant
- 03 Refrigeration Line set, driers, valves, nitrogen, brazing alloy
- 04 Controls Thermostats, sensors, wire, transformers
- 05 Labor - install Field hours by classification
- 06 Labor - start-up Commissioning and balancing hours
- 07 Subcontract Crane, electrical, structural
- 08 Other Permits, dumpsters, rental
The discipline that matters is timing . Cost codes must be posted weekly and compared against the estimate for the same code at the same percent complete.
Worked example : sheet metal was estimated at 180 hours. At the 40 percent complete milestone the crew has burned 96 hours.
Expected at 40 percent: 180 × 0.40 = 72 180 \times 0.40 = 72 180 × 0.40 = 72 hours.
Actual: 96 hours - a 24-hour, 33 percent unfavorable variance.
Projected at completion: 96 / 0.40 = 240 96 / 0.40 = 240 96/0.40 = 240 hours, a 60-hour overrun.
At $33.10 fully burdened, that variance is a $1,986 hit that is still 60 percent avoidable if the cause - poor takeoff, a coordination conflict, a crew skill gap - is found this week.
Work in Progress: Over- and Under-Billing
On contracts recognized under the percentage-of-completion method, revenue earned is: Earned Revenue = Contract Price × Cost Incurred to Date Total Estimated Cost \text{Earned Revenue} = \text{Contract Price} \times \frac{\text{Cost Incurred to Date}}{\text{Total Estimated Cost}} Earned Revenue = Contract Price × Total Estimated Cost Cost Incurred to Date
Overbilling (billings exceed earned revenue) is a liability, "billings in excess of costs and estimated earnings." It is normal, healthy, and it is the owner financing your job.
Underbilling (earned revenue exceeds billings) is an asset, "costs and estimated earnings in excess of billings." It means you are financing the owner , and it is the clearest early warning sign a surety or banker looks for.
Example : a $240,000 contract with $150,000 of total estimated cost. Cost incurred is $90,000, so the job is 60 percent complete and has earned $144,000. Billings to date are $120,000. The job is underbilled by $24,000 - the contractor has spent money that has not been invoiced.
Break-Even and Contribution Margin Break-Even Revenue = Fixed Overhead Gross Margin % \text{Break-Even Revenue} = \frac{\text{Fixed Overhead}}{\text{Gross Margin \%}} Break-Even Revenue = Gross Margin % Fixed Overhead
Worked example : annual fixed overhead of $240,000 with a 30 percent gross margin. Break-Even = $ 240,000 0.30 = $ 800,000 in annual revenue \text{Break-Even} = \frac{\$240{,}000}{0.30} = \$800{,}000 \text{ in annual revenue} Break-Even = 0.30 $240 , 000 = $800 , 000 in annual revenue
At $800,000 of revenue the company earns exactly zero. Every dollar above it contributes 30 cents of pre-tax profit; every dollar below costs 30 cents.
Now watch what a margin slip does. If discounting drives the gross margin from 30 percent to 25 percent, break-even rises to $ 240,000 / 0.25 = $ 960,000 \text{\textdollar}240{,}000 / 0.25 = \text{\textdollar}960{,}000 $ 240 , 000/0.25 = $ 960 , 000 . The company must sell $160,000 more work - a 20 percent revenue increase - just to stand still. This is the arithmetic behind the rule that price cuts are far more dangerous than volume dips.
Break-even in service calls : if the average service ticket contributes $210 of gross profit and monthly overhead is $27,300, the company must complete $ 27,300 / $ 210 = 130 \text{\textdollar}27{,}300 / \text{\textdollar}210 = 130 $ 27 , 300/ $ 210 = 130 calls a month before the first dollar of profit.
Why Profitable Contractors Run Out of Cash
- Cash drain Mechanism
- Retainage Up to 10 percent of every invoice held until the job reaches 50 percent completion
- Slow receivables Invoices at 60 to 90 days while payroll runs weekly
- Equipment deposits Long-lead rooftop units paid for months before they are billed
- Underbilling Work performed and not invoiced
- Growth itself Every new job consumes cash before it produces any
- Alabama Retainage and Prompt Pay
The Alabama Prompt Pay Act , Code of Alabama Title 8, Chapter 29, governs private construction payments. Section 8-29-3 sets three rules worth memorizing:
Retainage withheld by the owner may not exceed 10 percent.
After the project reaches 50 percent completion, no further retainage may be withheld.
Retainage never increases as it flows down. A contractor may not retain a greater percentage from a subcontractor than the owner retains from the contractor, and a subcontractor may not retain more from a sub-subcontractor than was retained from it.
Retainage held in excess of the permitted percentage accrues interest at 1 percent per month (12 percent per year) . Undisputed amounts are due within the statutory window after receipt of a proper pay application. Public work is governed separately.
Receivable Discipline
Age receivables every week in 30/60/90 buckets. A receivable at 90 days is worth materially less than its face amount.
Invoice the day the work is complete, not at month end.
Require deposits on equipment-heavy residential replacements.
Reconcile the schedule of values so that early activities carry a fair share of value - front-end loading beyond the value actually earned invites a rejected pay application.
A Twelve-Week Rolling Cash Forecast
List by week, for the next twelve weeks:
Beginning cash.
Collections - by customer, using realistic historical payment behavior, not contract terms.
Payroll and payroll taxes - the largest and least deferrable outflow.
Supplier payments - by due date, honoring discount dates where taken.
Fixed overhead - rent, insurance, vehicle notes, software.
Debt service and owner draws.
Ending cash , which becomes next week's beginning cash.
Any week that projects negative ending cash must be solved now - by accelerating a collection, negotiating supplier terms, or drawing on a line of credit arranged in advance. A line of credit is arranged when the company does not need it; a bank asked for money during a cash crisis is a bank that says no.