Answers to common questions about the Hestia Foundation, the RCP system, and open-source affordable housing.
The Hestia Foundation is a Portuguese non-profit organisation that develops and disseminates open-source construction systems for affordable, permanent, off-grid family housing. We believe that everyone deserves a safe, beautiful home they can own outright — without a 30-year mortgage.
Housing is a human need, not a product to be monopolised. By publishing all our research, designs, and protocols under Creative Commons (CC BY-SA 4.0), we ensure that anyone can build, adapt, and improve the system. Open source removes intellectual property barriers, enables rapid global replication, and prevents any single entity from controlling access to affordable housing.
Lagos, Algarve, Portugal. The Mediterranean climate, high solar availability, and severe local housing crisis make this an ideal testbed. However, the RCP system is designed for adaptation to any climate.
We pursue a diversified funding strategy: EU research grants (NEB, Horizon Europe, LIFE, Portugal 2030), private foundations, workshop revenue, and individual donations. Our target is €500,000–€1,000,000 in the first 24 months. All funding is directed exclusively to research, prototyping, and open-source dissemination.
The Hestia Foundation (non-profit) holds the intellectual property, research data, and open-source protocols. Hestia Build (commercial) executes construction, workshops, and material supply. This separation protects the open-source mission while enabling sustainable revenue to support ongoing research.
Ribbed Composite Panel. It's a structural sandwich panel made from timber I-joists (the "ribs"), EPAL Euro pallet slats (the infill), and OSB sheathing (the faces). The combination creates a lightweight, strong, highly insulated building element.
For Shell A (37.5m², single-storey):
For comparison, a conventional masonry home of similar size costs €150,000+ and requires a 30-year mortgage.
A team of 5–10 non-specialist volunteers can build a weathertight shell in 5–10 days. Complete interior finishing adds another 5 days. Total: 10–15 days from foundation to move-in ready.
No. The system is designed for non-specialists. If you can use a cordless drill and a circular saw, you can build this. Our 10-day workshop curriculum trains complete beginners to competency. The build protocol includes step-by-step instructions, daily checklists, and safety protocols.
The RCP system is engineered to Eurocode 5 (timber design standards) with the following design loads:
We are engaging an independent structural engineer (Ordem dos Engenheiros, Portugal) to verify all calculations and produce engineer-stamped drawings. The prototype will be structurally monitored for 12 months.
Building regulations vary by municipality and country. In Portugal, structures under 50m² often qualify for simplified permitting (licença de utilização or alvará de construção simplificado). We are working with the Municipality of Lagos to navigate the permitting process. Our engineer-stamped drawings and structural certification will support permit applications.
The 140mm wall cavity is filled with rockwool insulation (λ = 0.035 W/m·K), giving a wall U-value of approximately 0.25 W/m²·K — comparable to conventional construction. The system includes:
The prototype will be monitored for 12 months with temperature and humidity sensors to verify thermal performance.
All timber is treated with natural pine tar (traditional Scandinavian method) for weather and fire resistance. OSB sheathing is EN 300 structural grade with natural fire resistance. Rockwool insulation is non-combustible (A1 fire rating). A 10mm plasterboard interior lining can be added for 30-minute fire resistance if required by local regulations. The composting toilet is separated from living space.
With proper maintenance (pine tar reapplication every 5–7 years, roof membrane inspection every 10 years), the structure should last 50+ years. The timber I-joists and OSB are protected from moisture by the vapour barrier, breather membrane, and roof overhangs. The demountable design means individual panels can be replaced if damaged.
No. The default configuration is fully off-grid. The system includes:
In Algarve (3,000+ sunshine hours/year), this system provides ample electricity for lighting, refrigeration, water pumping, and device charging. The battery provides 2–3 days of autonomy.
Yes. The system is designed with grid connection as an option. The inverter can accept mains AC input, and the plumbing can accept municipal water. The off-grid package is the default because it eliminates lifetime utility dependency, but connection is straightforward if preferred.
A 4G/LTE modem with unlimited data SIM provides internet access. The solar/battery system easily powers this. Starlink or similar satellite service is also an option for rural locations without 4G coverage.
The composting toilet separates liquids and solids. Solids compost into usable soil amendment after 12 months. Liquids can be diluted and used as fertiliser or disposed of via greywater system. Greywater from sinks and showers can be filtered through a simple gravel bed and reed bed for garden irrigation.
Yes. That's the entire point. All documentation — build protocol, material lists, CAD drawings, cost data — is published open-source under CC BY-SA 4.0. Download it, adapt it to your climate and regulations, and build. If you want hands-on training, attend one of our 10-day workshops.
Workshops will be announced on our website and newsletter once the first prototype is complete. The cost is expected to be €500–€1,000 per person, including accommodation, meals, tools, safety equipment, and certification. Scholarships will be available for applicants from developing regions or disadvantaged backgrounds.
Yes. The RCP system scales efficiently. A workshop team that builds one house can build ten with the same skills. The Foundation supports community land trusts, housing cooperatives, and municipal partnerships for multi-home developments. Contact us to discuss your project.
Yes. The CC BY-SA 4.0 license permits commercial use, provided you attribute the Hestia Foundation and share any adaptations under the same license. We encourage builders, developers, and social housing providers to adopt and improve the system.
We seek partners in five categories:
See our Partners page or contact us directly.
We accept donations via bank transfer (once the non-profit is formally registered) and will soon offer Patreon and GitHub Sponsors options. For major donations or grants, please contact us to discuss partnership.
Our grant strategy targets five pillars:
See our Grant Strategy page for details.
If you are a grant professional with experience in NEB, Horizon Europe, or LIFE, we would love to hear from you. We also need consortium partners (universities, research institutes, municipalities) for multi-partner applications. See our Partners page.
Our highest priority is HORIZON-NEB-2026-01-REGEN-01 (€4M per project, deadline 01/12/2026). We are currently drafting the pre-proposal and seeking consortium partners. The NEB Boost (€30,000) will be applied for as soon as the prototype is built and documented.
Contact us and we'll get back to you within 48 hours.