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This Off-Grid Tiny House Has No Utility Bills—Here’s How I Built It with Solar & Rainwater
Discover the exact setup I used—solar panels, LiFePO4 batteries, and a rainwater collection system—to build a self-reliant, eco-friendly life in my tiny home.
Ark
August 02, 2025
Living Off-Grid: My Self-Built Solar-Powered Tiny House in the Bulgarian Mountains
Hi, I’m Ivan, and welcome to my off-grid, solar-powered, energy-efficient smart tiny house nestled in the mountains near Sofia, Bulgaria. I built this 40-square-meter (430-square-foot) home entirely by myself, and I’m excited to share every detail of this unique project with you.
A Perfect Location
My tiny house sits in a picturesque location in Eastern Europe’s mountains, just a 15- to 20-minute drive from Bulgaria’s capital, Sofia. The nearest village, with shops for essentials, is only 10 minutes away. The serene surroundings offer breathtaking views, perfect for morning coffee or evening sunsets, and endless opportunities for long walks in nature. It’s the ideal balance of isolation and accessibility.
The House: Compact and Functional
Measuring 4×10 meters, my tiny house is a single open space with a separate bathroom. The layout is thoughtfully divided into functional areas:
Kitchen: Fully equipped with an oven, washing machine, dishwasher, fridge, and microwave—everything needed for daily life.
Living Area: An open space where I play my drums, adding a creative vibe to the home.
Workstation: A corner with my custom-built desk, music studio equipment, laptop, and monitor.
Sleeping Area: Features a bed with a built-in wardrobe, USB chargers, and wireless chargers. A small window next to the bed lets in fresh air and frames stunning sunset views.
All the furniture, including the desk and bed, is custom-made by me to maximize space and functionality.
Building the Dream
The house is built on a timber frame using pinewood planks, with 15 cm of rock wool insulation in the walls, 20 cm in the ceilings, and 15 cm of rock wool plus 5 cm of XPS for the floor. The foundation consists of concrete pillars drilled 70 cm into the ground, below Bulgaria’s freezing point, ensuring stability.
I designed the house in SketchUp, pre-cut all materials, and assembled the structure in stages. The process took about two weeks, from laying the foundation to completing the main structure. Key steps included:
Assembling the bottom frame and floors (10 days).
Building walls and ceilings reinforced with OSB sheets.
Wrapping the structure with a waterproof membrane.
Installing a PVC membrane roof.
The three panoramic windows, made of triple chemically treated glass and weighing 136 kg each, were a challenge to install, requiring help from friends. I also crafted the entrance door from scratch, using a SketchUp design, XPS insulation, and a smart lock, finished to match the interior’s laminate flooring.
To keep the aesthetic clean, I hid all pipes and cables between the frame and drywall, running them under the floor and in the ceiling. The electrical setup is extensive, with each socket on its own switch and every LED connected to a Wi-Fi relay for integration with a smart home system. Security cameras, ventilation fans, and other features add to the high-tech setup. The bathroom and kitchen’s hot and cold water pipes are also concealed within the walls.
Drywalling, especially on the ceiling, was tough but manageable with some creative problem-solving. Plastering and sanding took a week, followed by priming and painting the walls a crisp snow white. The floor features a vapor membrane, XPS insulation, floor heating film, and laminate flooring.
The Bathroom: A Grungy Retreat
The 4-square-meter bathroom is designed with a rugged, natural aesthetic. It includes a toilet, shower, urinal, and hygienic shower. I applied a liquid mix (Ceresit CL51) for waterproofing and experimented with gypsum plaster to mimic travertine stone, creating a textured, earthy look. A sliding door, also self-made, saves space. The bathroom is still a work in progress, awaiting a sink and mirror.
For the exterior, I chose a Scandinavian minimalist style, using planed planks treated with a colored preserver. I removed the corners for a sleek look and added a small terrace in the same style, blending the house seamlessly with its surroundings.
Off-Grid Living: Power and Water
The house operates entirely off-grid, independent of city utilities. Here’s how it works:
Solar Power
Panels: Four 660W Canadian Solar panels (originally six, but four suffice).
Batteries: A 48V system with 560 Ah lithium ferrophosphate batteries, providing ~30 kWh of energy—enough for 5–7 days of autonomy.
Inverter: A 5 kW Growatt SPF 5000ES all-in-one inverter powers the house, charges batteries, and supports generator backup. A mobile app tracks performance.
Backup: On rare foggy days (10–15 times in two years), I use a gasoline generator to charge the batteries.
Water Supply
Instead of digging a costly well, I built a rainwater collection system:
A 2,000 L underground tank collects water from the gutters via a filtered pipe.
A 100L indoor tank and pressure pump distribute water to the kitchen, bathroom, and toilet.
For one person, a few rainy days provide nearly a month’s water supply. For a family, a larger tank or well would be ideal.
Graywater
A three-chamber PVC recycling tank processes greywater:
Heavy waste dissolves with bacteria.
Anaerobic processing.
Final cleaning, making the water safe for ground disposal.
Heating and Cooling
Summer: An AC unit cools the house, powered by excess solar energy.
Winter: On sunny days, passive solar heating warms the house. On cloudy days, I use a propane infrared heater (a 27L bottle costs $15 and lasts a week). Total heating costs for Bulgaria’s two cold months are around $800.
Cooking: The kitchen uses propane for efficiency and preference over electric induction.
Internet
A 4G router provides a 100 Mbps plan (real-world speeds ~20 Mbps), sufficient for my needs, supplemented by unlimited 5G on my phone.
Reflections and Future Plans
Living in this tiny house for two years has been a rewarding experiment in self-sufficiency and minimalism. The smart systems, off-grid utilities, and custom design make it both functional and personal. I’m planning to sell this house next year and build a new one, applying lessons learned—like a larger water tank for future projects.
This isn’t my only build; I constructed a similar but larger house for a neighbor. If you’re curious to see it or want more details on my solar setup, let me know! Follow my journey on Instagram or subscribe to my channel for updates on my next project.
Thanks for exploring my tiny house with me. It’s been a labor of love, and I hope it inspires you to dream big—no matter how small the space.
