Build It. Improve It. Deploy It.
HFS is fully open source. Every hardware design, hydraulic model, and line of controller code is freely available for anyone to build, modify, and deploy.
Licensing
Hardware
CERN-OHL-S v2
The same license used by CERN for its open hardware projects. You can build, modify, and distribute the hardware designs freely. If you distribute modified versions, you must share your changes under the same license.
Software
GPL-3.0
The standard free software license. You can use, modify, and distribute the software freely. If you distribute modified versions, you must also release them as open source under GPL-3.0.
Bill of Materials
All 15 components with specs, quantities, and estimated costs. Filter by zone.
| Zone | Component | Spec | Qty | Est. Cost | Source |
|---|---|---|---|---|---|
| Controller | Raspberry Pi 4B | 4GB RAM | 1 | $75 | PiShop / Amazon |
| Controller | Relay Board | 8-channel, 12V | 1 | $15 | Amazon |
| Controller | Thermal Sensor Array | MLX90640, 32×24px IR | 2 | $240 | Adafruit / Mouser |
| Controller | Solenoid Valves | 1" NPT, 12V DC, normally closed | 4 | $640 | Amazon / Irrigation supply |
| Zone 1 | Roof Rotary Sprinklers | Impact-style, 2.0 GPM @ 30 PSI | 6 | $540 | Home Depot / Irrigation supply |
| Zone 2 | Eave Mist Nozzles | Fine mist, 1.2 GPM @ 20 PSI | 16 | $1280 | Amazon / Irrigation supply |
| Zone 2 | Eave Mounting Rail | Aluminum, UV-resistant | 1 | $60 | Home Depot |
| Zone 3 | Foam Applicators | 0.8 GPM, Class-A compatible | 6 | $720 | Forestry Suppliers |
| Zone 3 | Class-A Foam Concentrate | 5 gal, 0.3%, USFS approved, biodegradable | 1 | $85 | Forestry Suppliers |
| Zone 4 | Perimeter Sprinkler Heads | Pop-up or fixed, 1.5 GPM @ 25 PSI | 8 | $768 | Home Depot / Irrigation supply |
| Supply | HDPE Water Tank | 10,000 gallon, UV-stabilized | 1 | $2800 | Tank Depot / Local supplier |
| Supply | Centrifugal Pump | 2HP, 50 GPM max, 115V | 1 | $350 | Amazon / Pump supply |
| Supply | HDPE Manifold Piping | 1" HDPE, fittings, 200 ft | 1 | $180 | Home Depot / Plumbing supply |
| Supply | Pressure Regulators | Adjustable, per-zone | 4 | $240 | Irrigation supply |
| Supply | Backflow Preventer | RPZ type, code-compliant | 1 | $120 | Plumbing supply |
| Total: | $8,113 | ||||
Phased Build Plan
Build incrementally — start with the controller, add zones as budget allows.
Phase 1
~$800
Controller + Sensors
Raspberry Pi, relay board, thermal sensors, solenoid valves, wiring
Phase 2
~$600
Roof + Eave System
Roof rotors, eave nozzles, mounting hardware, zone piping
Phase 3
~$2,500
Tank + Pump + Foam
10,000 gal HDPE tank, 2HP pump, foam concentrate, foam applicators
Phase 4
~$1,500
Full Perimeter
Perimeter heads, manifold piping, regulators, backflow preventer, trenching
Engineering Files
EPANET Model
Hydraulic simulation file (.inp) — validated for all 4 zones.
Controller Code
Python controller for Raspberry Pi — sensor integration, zone control, alerts.
Coming SoonStandards Compliance Reference
Relevant codes and standards for residential wildfire sprinkler systems.
| Code | Description |
|---|---|
| NFPA 13D | Standard for Sprinkler Systems in Residential Occupancies |
| IRC R327 | International Residential Code — Wildfire-Urban Interface |
| NFPA 22 | Standard for Water Tanks for Private Fire Protection |
| NEC Article 547 | Agricultural Buildings (applicable to outdoor pump wiring) |
| NFPA 72 | National Fire Alarm and Signaling Code |
Share Your Build
Built an HFS system? Share your experience with the community. Send us photos, documentation, or feedback.
Email your build photos and documentation to builds@HFS.dev — we're collecting community builds for a future showcase page.