### Lifespan-based Cost Analysis: Earthbag Dwelling #### Summary Costs (per Person Based On 1000 People) | cost | dollars | hours | | -------------------------------- | ------- | ----- | | amortized initial building costs | $312 | 0.84 | | annual maintenance | $180 | 29.20 | | **total** | $492 | 30.04 | #### Amortized Initial Building Costs | Component | Initial Cost ($/hrs) | Lifespan | Annual Cost ($/hrs) | Per Person ($/hrs) | Notes | | ------------------- | -------------------- | -------- | ------------------- | ------------------ | --------------------------------------------------------- | | Branch sewer lines | $200,000/600 | 50 | $4,000/12.00 | $4.00/0.01 | Small diameter lines from main to each dwelling $500 each | | Branch water lines | $140,000/400 | 50 | $2,800/8.00 | $2.80/0.01 | Individual water connections $350 each | | Individual plumbing | $560,000/1600 | 30 | $18,667/53.33 | $18.67/0.05 | sets of fixtures/supply lines $1,400 each | | Bathroom walls | $320,000/1200 | 50 | $6,400/24.00 | $6.40/0.02 | walls and door $800 each | | Ventilation | $240,000/800 | 20 | $12,000/40.00 | $12.00/0.04 | Bathroom exhaust fans and ducting $600 each | | Electrical | $80,000/400 | 30 | $2,667/13.33 | $2.67/0.01 | Light/GFCI outlet per bathroom $200 each | | Finishes | $280,000/1200 | 15 | $18,667/80.00 | $18.67/0.08 | Tile, waterproofing, fixtures $700 each | | **Total** | **$1,820,000/6200** | - | **$65,201/230.66** | **$65.20/0.23** | Materials and direct labor only | #### Annual Maintenance Costs | system | material cost | hours | per person cost | per person hours | notes | | ------------------ | ------------- | ---------- | --------------- | ---------------- | ------------------------------------ | | plumbing repairs | $60,000 | 0 | $60.00 | 0.00 | professional service contracts | | water heater maint | $20,000 | 0 | $20.00 | 0.00 | annual inspections, repairs | | ventilation | $8,000 | 0 | $8.00 | 0.00 | filter changes, fan maintenance | | electrical systems | $5,000 | 0 | $5.00 | 0.00 | minimal electrical maintenance | | finishes | $15,000 | 0 | $15.00 | 0.00 | grout sealing, caulking, repairs | | infrastructure | $40,000 | 0 | $40.00 | 0.00 | main line maintenance, pumps | | **total** | **$180,000** | **29,200** | **$180.00** | **29.20** | most maintenance professionally done | ### Revised Amortized Initial Building Costs (per 1000 people) | Component | Initial Cost ($/hrs) | Lifespan | Annual Cost ($/hrs) | Per Person ($/hrs) | Notes | |-----------|---------------------|-----------|--------------------|--------------------|--------| | Branch sewer lines | $200,000/300 | 50 | $4,000/6.00 | $4.00/0.01 | Small diameter lines from main to each dwelling | | Branch water lines | $150,000/250 | 50 | $3,000/5.00 | $3.00/0.01 | Individual water connections | | Individual plumbing | $800,000/1200 | 30 | $26,667/40.00 | $26.67/0.04 | Fixtures, supply lines, drains per unit | | Bathroom walls/structure | $400,000/600 | 50 | $8,000/12.00 | $8.00/0.01 | Additional 35 sq ft per dwelling | | Ventilation | $200,000/300 | 20 | $10,000/15.00 | $10.00/0.02 | Bathroom exhaust fans and ducting | | Finishes | $300,000/400 | 15 | $20,000/26.67 | $20.00/0.03 | Tile, waterproofing, fixtures | | **Total** | **$2,050,000/3050** | - | **$71,667/104.67** | **$71.67/0.10** | Significantly reduced from original estimate | Notes on major changes: - Removed water heaters (centralized) - Removed main sewer/water infrastructure (needed in both scenarios) - Removed sewage pumps (needed in both scenarios) - Reduced branch line costs (smaller diameter, shorter runs) - Reduced plumbing costs (simpler individual installations) - Removed separate heating systems (part of dwelling) - Removed separate electrical (part of dwelling) - Adjusted wall/structure costs to reflect just the additional bathroom space - Reduced finishes cost to reflect smaller spaces This revised calculation shows a much more realistic incremental cost for adding distributed bathrooms to dwellings versus centralizing them. The per-person annual cost drops from $312 to $71.67, reflecting just the additional infrastructure and construction needed beyond what would already exist in the dwelling.