whirrwork

Robot or Human?

Window and facade cleaning

Rope-access or lift crew (contract) vs Cleaning-drone service

Whirrwork modelled estimates, not facts. Methodology · Track record

Human · Per year$150,000Rope or lift contractor
Robot · Per year$54,000Drone cleaning service
Paybackimmediate
Crossover yearnowBase-case year (earliest to latest across scenarios)

On these numbers the robot option is clearly cheaper.

United States · USD · BLS OEWS May 2025 national medians by SOC occupation

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Workload
Assumption

Facade square feet cleaned per year (e.g. 60,000 sq ft twice).

Assumption

Working hours per day.

Assumption

Working days per month.

Assumption

Months per year (volume is annual).

People
U.S. Bureau of Labor Statistics

BLS OEWS May 2025 national median hourly wage, SOC 37-2019.

U.S. Bureau of Labor Statistics

Wages and salaries were 70.0% of total employer compensation cost for private industry workers in June 2026 (ECEC), so total cost = wage / 0.70.

ilostat.ilo.org

Nominal 4.4% a year, 2015-2025 (ILOSTAT hourly earnings).

Prices
Derived Sky PSI (drone cleaning company)

Low-to-mid point of conventional lift/rope bids $0.50-$3.50/sq ft. Source is a drone cleaning company, so treat as their view of the competition.

Derived Vista Drone Cleaning

Upper end of commercial drone-cleaning published rates ($0.12-$0.25 Miami; $0.25-$0.50 Southern California).

Robot
Assumption

Facade sq ft per drone-hour including setup and moves.

Derived Lucid Bots

Midpoint of Lucid Bots Sherpa operator subscription $2,950-$4,600/month.

Assumption

Pilot certification, insurance and gear to run your own drone.

Assumption

Subscription commitment in years.

Assumption

Share of working hours flyable (wind, rain, battery swaps).

Assumption

Work lost to faults.

Assumption

Share still done by rope or lift (recessed windows, detail work, inspection).

Assumption

Crew minutes per drone-hour: pilot plus a ground person for the hose and the public.

Assumption

kWh per drone-hour.

Assumption

Electricity price per kWh (USD). Check your bill; energy is rarely a big line.

Money
Assumption

Annual financing / discount rate. Nobody publishes yours; 8% is a round mid-2026 commercial borrowing guess.

Assumption

Years in the NPV comparison.

Assumption

Share of a human service price that is labour (rises with wages). Used to escalate and to adjust US service prices to other countries.

Assumption

Share of a robot service price that is labour (pilot, technician). The rest is equipment, which learning curves make cheaper.

Assumption

Share of a lease or RaaS fee that pays for hardware (learns down). The rest is service and support (moves with wages).

Download these results (CSV)

Results

OptionPer monthPer yearPer unit (sq ft)UpfrontPaybackBreak-even utilisation5-year NPV vs baseline
Human Rope or lift contractor Baseline $12,500$150,000$1.25— — — —
Robot Drone cleaning service $4,500$54,000$0.45— immediate — $416,012
Robot Run your own cleaning drone (subscription) $6,961$83,532$0.696$5,000 0.9 months 2%
Utilisation 6%
 $299,089

What moves the answer most

Each bar shows the 5-year NPV of the best robot option when one input moves to the low or high end of its range, with the rest held at your values.

5-year NPV vs baseline: Drone cleaning service5-year NPV vs baseline: Drone cleaning serviceWorkloadlow value: 30000 → $104,003high value: 500000 → $1,733,382Rope or lift contractorlow value: 0.5 → $105,241high value: 3.5 → $1,348,323Work that stays humanlow value: 0.05 → $494,014high value: 0.4 → $312,009Drone cleaning servicelow value: 0.12 → $469,020high value: 0.5 → $314,073Financing and discount ratelow value: 0.05 → $447,747high value: 0.12 → $378,356Wage growth per yearlow value: 0.0236 → $405,945high value: 0.0636 → $426,464$416,012low valuehigh valueSource: Whirrwork Robot-or-Human model v1.0.0 (whirrwork.com/tools/robot-vs-human/window-facade-cleaning/). Modelled estimate, not a fact.

Cost per unit to 2035

Real terms (today's money). Robot hardware follows Wright's law; wages follow each country's history. Shaded band: robots-slow to robots-fast scenarios. Whirrwork modelled estimates, not facts.

ChartHuman cost per unit (Base), Robot cost per unit (Base), Robot cost per unit (Robots fast), Robot cost per unit (Robots slow). Source: Whirrwork Robot-or-Human model v1.0.0 (whirrwork.com/tools/robot-vs-human/window-facade-cleaning/). Modelled estimate, not a fact.$0.00$0.50$1.002026202720282029203020312032203320342035USD / sq ftscenario rangeHuman cost per unit (Base)Robot cost per unit (Base)Robot cost per unit (Robots fast)Robot cost per unit (Robots slow)Source: Whirrwork Robot-or-Human model v1.0.0 (whirrwork.com/tools/robot-vs-human/window-facade-cleaning/). Modelled es…

Crossover year: now

What the spreadsheet misses

Safety
Takes people off ropes and lifts for routine washes, the main reason buildings try it.
Quality
Soft-wash rinsing is not squeegee-clean glass; ask for before and after photos.
Flexibility
Rope teams also inspect sealant and fix things.
Edge cases
Wind, tall towers, dense downtowns and airspace rules limit drones.
Customer experience
Tenants prefer not having a person at the window.
Jobs and redeployment
Rope access shifts toward inspection and repair.
Regulation
Drone pilot certification (FAA Part 107 or local equivalent), tethered-flight and water-runoff rules apply.

Related

Sources on this page

  1. Conventional lift/rope exterior cleaning bids $0.50-$3.50 per sq ft (for comparison with drone cleaning) Sky PSI (drone cleaning company), 2026-10 · vendor
  2. Drone facade/window cleaning, commercial buildings: $0.12-$0.25 per sq ft Vista Drone Cleaning, 2026-10 · vendor
  3. Lucid Bots Sherpa cleaning drone subscription for operators: $2,950-$4,600 per month Lucid Bots, 2026-10 · vendor
  4. Occupational Employment and Wage Statistics, May 2025 (median hourly wage by occupation) U.S. Bureau of Labor Statistics, 2025-05
  5. Employer Costs for Employee Compensation, June 2026: wages and salaries 70.0% of private-industry compensation (series CMU2020000000000P) U.S. Bureau of Labor Statistics, 2026-06
  6. Mean nominal hourly earnings of employees by sex and occupation (ISCO-08), DF_EAR_EHRA_SEX_OCU_CUR_NB ILOSTAT (International Labour Organization), from national labour force and earnings surveys, 2025
  7. Labour cost levels by NACE Rev. 2 activity (lc_lci_lev): Germany 2022-2025, total labour cost vs wages and salaries per hour Eurostat, 2025
  8. Rates and thresholds for employers 2025 to 2026 (employer Class 1 NIC 15% above £5,000) HM Revenue & Customs, 2025-04-06
  9. 令和6年賃金構造基本統計調査 (Basic Survey on Wage Structure 2024), table 1 by occupation Ministry of Health, Labour and Welfare, Japan (via e-Stat), 2024-06
  10. Average monthly earnings of employees by sex and economic activity, DF_EAR_EMTA_SEX_ECO_CUR_NB ILOSTAT (International Labour Organization), 2022
  11. Average annual wage of employed persons in urban units in 2024 (by position and by region) National Bureau of Statistics of China, 2025-05-20
  12. Euro foreign exchange reference rates (cross rates to USD), via Frankfurter European Central Bank, 2026-10-23
  13. Wright, T. P. (1936). Factors affecting the cost of airplanes. Journal of the Aeronautical Sciences, 3(4), 122-128 Journal of the Aeronautical Sciences, 1936
  14. Nagy, B., Farmer, J. D., Bui, Q. M., & Trancik, J. E. (2013). Statistical basis for predicting technological progress. PLoS ONE, 8(2), e52669 (62 technologies; Wright's law among the best hindcasters; errors grow with horizon) PLoS ONE, 2013