Plumbing Business input evidence register
45 financial inputs with their assumptions, calculation bases and cited sources.
Read the supported claim, observation period, geography and units together. A source access date records when it was consulted. A model assumption identifies a selected amount or target; a calculated result follows from those inputs and does not establish observed demand or a quoted opening budget.
Case updated October 19, 2026. These notes accompany the complete case methodology and source register.
Dataset use notice: no Creative Commons license or DOI is asserted. Referenced material remains subject to its publisher’s terms.
These notes explain the opening budget, annual forecast and calculator assumptions. Linked sources provide the support described in each note; they do not necessarily confirm the selected amounts. Check scenario assumptions against local quotes and operating records.
- Model assumption
Applies to: Total opening budget · Lower opening budget · Upper opening budget
Authored total $125,000 equals the eight opening allocations. Low $45,000 assumes a qualified owner already holding suitable vehicle/tools and solo staged work; high $220,000 adds newer assets, diagnostics and reserve for one route. None is a sourced package price or minimum funding guarantee.
- Model assumption
Applies to: Used service van and secure upfit
A $36,000 combined inspected-used-van and secure-upfit allowance is selected; Ford's $48,400 new MSRP is context, not a used quote.
- Model assumption
Applies to: Press, cutting, diagnostic and limited drain equipment
A $14,000 selection allowance covers press/cutting/diagnostic tools and limited drain equipment; manufacturer material, diameter and blockage limits define exclusions, not this price.
- Model assumption
Applies to: Opening fittings, valves and ordinary fixture stock
A $6,000 controlled opening stock allowance is authored for common fittings/valves/ordinary fixtures. Replace with actual supplier and service-menu evidence.
- Model assumption
Applies to: PPE and customer-property protection
A $3,000 PPE, protection, testing and safety allowance is authored, not a price bundle; occupational hazards support the need.
- Model assumption
Applies to: Licensing, registration, insurance and deposits
An $8,000 allowance covers initial licensing, registration, insurance and deposits. Texas's coverage limit is not a premium; actual jurisdiction and broker quotes replace it.
- Model assumption
Applies to: Dispatch, website, phones and launch systems
A $6,000 dispatch, website, phone and launch-system allowance is authored and excludes any claim of purchased software or account activation.
- Model assumption
Applies to: Small secure storage setup and deposits
A $2,000 secure-storage setup/deposit allowance is authored and requires local lawful-use and lease evidence.
- Model assumption
Applies to: Unrestricted working-capital reserve
The unrestricted reserve is an authored opening funding use. The shared ramp analysis shows the peak cumulative operating deficit separately from the smaller first-year operating loss. Collections, parts, tax, debt and replacement timing still need a dated cash plan before sufficiency can be judged.
- Model assumption
Applies to: Revenue (Year 1)
Authored Year 1: 2.1 average completed jobs per field day x 5 days x 4.33 weeks/month x 12 months x $410 net invoice, rounded to whole USD. Year one averages the monthly shares 20%,30%,40%,50%,60%,70%,80%,90%,100%,100%,100%,100%; Years two and three are full-volume. Later prices need local validation. Other operator menus bound service possibilities, not this weighted invoice or demand.
- Model assumption
Applies to: Parts, payment fees, route fuel and job-linked rework (Year 1)
Authored Year 1 sales-linked cost equals 25% of that year's revenue: 19% parts/consumables, 3% payment allowance, 2% route fuel, 1% other job-linked rework. Stripe's current domestic online rate is 2.9% plus $0.30; 3% is an allowance, not an all-method contract. Paid labor stays in payroll. Rework time also reduces route capacity.
- Model assumption
Applies to: Paid working owner, helper and employer costs (Year 1)
Authored Year 1 payroll $135000. The full owner/helper base remains paid from launch, including the slow ramp. Mature $135,000 = $80,000 owner economic labor allowance + $39,000 helper pay (30 hours x 52 paid weeks x $25/hour) + $16,000 employer/leave/coverage allowance. Owner wage/tax classification depends on entity. Later totals are selected pay/burden adjustments, not sourced inflation.
- Model assumption
Applies to: Van, insurance, storage, dispatch, marketing and administration (Year 1)
Authored Year 1 other overhead $45000. Mature $45,000 = $12,000 insurance + $9,000 fixed van/tool upkeep + $4,800 storage + $4,200 software/communications + $9,000 marketing + $6,000 administration/training. These allowances require local quotes; no cited coverage limit is treated as a premium. Job-linked fuel is separate and loan principal, interest, depreciation and capital replacement are excluded.
- Model assumption
Applies to: Revenue (Year 2)
Authored Year 2: 3 average completed jobs per field day x 5 days x 4.33 weeks/month x 12 months x $410 net invoice, rounded to whole USD. Year one averages the monthly shares 20%,30%,40%,50%,60%,70%,80%,90%,100%,100%,100%,100%; Years two and three are full-volume. Later prices need local validation. Other operator menus bound service possibilities, not this weighted invoice or demand.
- Model assumption
Applies to: Parts, payment fees, route fuel and job-linked rework (Year 2)
Authored Year 2 sales-linked cost equals 25% of that year's revenue: 19% parts/consumables, 3% payment allowance, 2% route fuel, 1% other job-linked rework. Stripe's current domestic online rate is 2.9% plus $0.30; 3% is an allowance, not an all-method contract. Paid labor stays in payroll. Rework time also reduces route capacity.
- Model assumption
Applies to: Paid working owner, helper and employer costs (Year 2)
Authored Year 2 payroll $135000. The full owner/helper base remains paid from launch, including the slow ramp. Mature $135,000 = $80,000 owner economic labor allowance + $39,000 helper pay (30 hours x 52 paid weeks x $25/hour) + $16,000 employer/leave/coverage allowance. Owner wage/tax classification depends on entity. Later totals are selected pay/burden adjustments, not sourced inflation.
- Model assumption
Applies to: Van, insurance, storage, dispatch, marketing and administration (Year 2)
Authored Year 2 other overhead $45000. Mature $45,000 = $12,000 insurance + $9,000 fixed van/tool upkeep + $4,800 storage + $4,200 software/communications + $9,000 marketing + $6,000 administration/training. These allowances require local quotes; no cited coverage limit is treated as a premium. Job-linked fuel is separate and loan principal, interest, depreciation and capital replacement are excluded.
- Model assumption
Applies to: Revenue (Year 3)
Authored Year 3: 3 average completed jobs per field day x 5 days x 4.33 weeks/month x 12 months x $410 net invoice, rounded to whole USD. Year one averages the monthly shares 20%,30%,40%,50%,60%,70%,80%,90%,100%,100%,100%,100%; Years two and three are full-volume. Later prices need local validation. Other operator menus bound service possibilities, not this weighted invoice or demand.
- Model assumption
Applies to: Parts, payment fees, route fuel and job-linked rework (Year 3)
Authored Year 3 sales-linked cost equals 25% of that year's revenue: 19% parts/consumables, 3% payment allowance, 2% route fuel, 1% other job-linked rework. Stripe's current domestic online rate is 2.9% plus $0.30; 3% is an allowance, not an all-method contract. Paid labor stays in payroll. Rework time also reduces route capacity.
- Model assumption
Applies to: Paid working owner, helper and employer costs (Year 3)
Authored Year 3 payroll $135000. The full owner/helper base remains paid from launch, including the slow ramp. Mature $135,000 = $80,000 owner economic labor allowance + $39,000 helper pay (30 hours x 52 paid weeks x $25/hour) + $16,000 employer/leave/coverage allowance. Owner wage/tax classification depends on entity. Later totals are selected pay/burden adjustments, not sourced inflation.
- Model assumption
Applies to: Van, insurance, storage, dispatch, marketing and administration (Year 3)
Authored Year 3 other overhead $45000. Mature $45,000 = $12,000 insurance + $9,000 fixed van/tool upkeep + $4,800 storage + $4,200 software/communications + $9,000 marketing + $6,000 administration/training. These allowances require local quotes; no cited coverage limit is treated as a premium. Job-linked fuel is separate and loan principal, interest, depreciation and capital replacement are excluded.
- Model assumption
Applies to: Revenue (Year 4)
Authored Year 4: 3 average completed jobs per field day x 5 days x 4.33 weeks/month x 12 months x $430 net invoice, rounded to whole USD. Year one averages the monthly shares 20%,30%,40%,50%,60%,70%,80%,90%,100%,100%,100%,100%; Years two and three are full-volume. Later prices need local validation. Other operator menus bound service possibilities, not this weighted invoice or demand.
- Model assumption
Applies to: Parts, payment fees, route fuel and job-linked rework (Year 4)
Authored Year 4 sales-linked cost equals 25% of that year's revenue: 19% parts/consumables, 3% payment allowance, 2% route fuel, 1% other job-linked rework. Stripe's current domestic online rate is 2.9% plus $0.30; 3% is an allowance, not an all-method contract. Paid labor stays in payroll. Rework time also reduces route capacity.
- Model assumption
Applies to: Paid working owner, helper and employer costs (Year 4)
Authored Year 4 payroll $141000. The full owner/helper base remains paid from launch, including the slow ramp. Mature $135,000 = $80,000 owner economic labor allowance + $39,000 helper pay (30 hours x 52 paid weeks x $25/hour) + $16,000 employer/leave/coverage allowance. Owner wage/tax classification depends on entity. Later totals are selected pay/burden adjustments, not sourced inflation.
- Model assumption
Applies to: Van, insurance, storage, dispatch, marketing and administration (Year 4)
Authored Year 4 other overhead $47000. Mature $45,000 = $12,000 insurance + $9,000 fixed van/tool upkeep + $4,800 storage + $4,200 software/communications + $9,000 marketing + $6,000 administration/training. These allowances require local quotes; no cited coverage limit is treated as a premium. Job-linked fuel is separate and loan principal, interest, depreciation and capital replacement are excluded.
- Model assumption
Applies to: Revenue (Year 5)
Authored Year 5: 3 average completed jobs per field day x 5 days x 4.33 weeks/month x 12 months x $450 net invoice, rounded to whole USD. Year one averages the monthly shares 20%,30%,40%,50%,60%,70%,80%,90%,100%,100%,100%,100%; Years two and three are full-volume. Later prices need local validation. Other operator menus bound service possibilities, not this weighted invoice or demand.
- Model assumption
Applies to: Parts, payment fees, route fuel and job-linked rework (Year 5)
Authored Year 5 sales-linked cost equals 25% of that year's revenue: 19% parts/consumables, 3% payment allowance, 2% route fuel, 1% other job-linked rework. Stripe's current domestic online rate is 2.9% plus $0.30; 3% is an allowance, not an all-method contract. Paid labor stays in payroll. Rework time also reduces route capacity.
- Model assumption
Applies to: Paid working owner, helper and employer costs (Year 5)
Authored Year 5 payroll $147000. The full owner/helper base remains paid from launch, including the slow ramp. Mature $135,000 = $80,000 owner economic labor allowance + $39,000 helper pay (30 hours x 52 paid weeks x $25/hour) + $16,000 employer/leave/coverage allowance. Owner wage/tax classification depends on entity. Later totals are selected pay/burden adjustments, not sourced inflation.
- Model assumption
Applies to: Van, insurance, storage, dispatch, marketing and administration (Year 5)
Authored Year 5 other overhead $49000. Mature $45,000 = $12,000 insurance + $9,000 fixed van/tool upkeep + $4,800 storage + $4,200 software/communications + $9,000 marketing + $6,000 administration/training. These allowances require local quotes; no cited coverage limit is treated as a premium. Job-linked fuel is separate and loan principal, interest, depreciation and capital replacement are excluded.
- Model assumption
Applies to: Net sale per completed plumbing job (base scenario) · Net sale per completed plumbing job (lower sensitivity) · Net sale per completed plumbing job (upper sensitivity)
Authored $410 net invoice = 20% diagnostic-only x $125 + 35% ordinary repair x $350 + 30% supplied fixture x $600 + 15% limited drain diagnosis/clearing x $550. Low $200 and high $700 are sensitivity selections, not market percentiles. Scope, parts and duration must change together; quotes from different providers are not averaged into a measured ticket.
- Model assumption
Applies to: Completed plumbing jobs per field day across one van (base scenario) · Completed plumbing jobs per field day across one van (lower sensitivity) · Completed plumbing jobs per field day across one van (upper sensitivity)
Authored one-van base 3 completed jobs/day; range 1-4 is a sensitivity, not validated capacity. Selected service times 0.75/1.5/2.5/2 hours under the 20/35/30/15% mix give 1.725 service hours/job. Add 0.75 travel/access/pack hours and 0.25 callback hours/job. Three jobs use 8.175 route hours/day; five days plus 6 admin hours gives 46.875 owner hours/week. Four gives 60.5 hours and is outside the 50-hour roster unless the mix, route or paid cover changes. Helper 30 weekly hours include three selected route days (24.525 hours including travel/access/pack and callbacks) plus 5.475 hours loading/stock/tool tasks. Owner serves safe solo calls on two other days; two-person tasks are scheduled on helper days. More simultaneous assistance requires a revised roster. The helper does not halve elapsed time.
- Model assumption
Applies to: Trading days per week (base scenario) · Trading days per week (lower sensitivity) · Trading days per week (upper sensitivity)
Authored five field days with four/six-day sensitivity. The annual calendar uses the same 4.33 weeks/month as the calculator, or 51.96 averaged weeks/year. Closures, leave or owner absence require reduced saleable days or separately funded qualified relief; no backup licensed lead is assumed. More field days do not eliminate rest, overtime, supervision or owner administration; rebuild the roster when changing days.
- Model assumption
Applies to: Monthly fixed operating costs
Authored mature monthly fixed cost $15,000 = ($135,000 paid owner/helper/employer costs + $45,000 other overhead)/12. Detailed annual allocations are stated in methodology and payroll/overhead evidence. Financing, tax, depreciation, replacement capex and cash timing are excluded.
- Model assumption
Applies to: Contribution margin
Authored 75% contribution retains revenue after 19% parts/consumables, 3% payments, 2% route fuel and 1% job-linked rework. This is not an observed trade margin. Labor is fixed in this sensitivity; changing the service mix or hiring creates a new cost regime.
- Model assumption
Applies to: Opening sales as a share of mature volume · Monthly increase toward mature volume · Forecast horizon (months)
Authored monthly ramp begins at 20% of mature monthly sales, adds 10 percentage points per month to the 100% cap, and displays 12 months. It holds the paid owner/helper fixed base constant from launch. Year one sums these same twelve months, and Years two/three sum twelve full-volume months, within whole-dollar rounding; neither is observed booking history.