What is the most affordable type of home to build? Eco-friendly cottages explained

Building a home doesn’t have to cost six figures. If you’re looking to own land and build something simple, durable, and kind to the planet, the most affordable type of home to build today is an eco-friendly cottage. Not the fancy, Instagram-ready kind with solar panels glued to the roof like decorations. I mean the real deal: small, well-insulated, built with local or reclaimed materials, and designed to need almost nothing from the grid.

Back in 2023, the average cost to build a standard 2,000-square-foot house in Ireland was around €350,000. That’s not even counting the land. But a basic eco-friendly cottage under 500 square feet? You can build one for under €60,000 - including foundation, walls, roof, windows, and basic plumbing. Some people have done it for less than €40,000 if they’re willing to do the labor themselves and source materials smartly.

Why eco-friendly cottages are cheaper to build

Traditional homes are expensive because they’re overbuilt. They have too many rooms, oversized windows, fancy finishes, and complex HVAC systems that cost more to install than the walls. Eco-friendly cottages strip all that away. They focus on what actually matters: warmth in winter, cool in summer, dry inside, and low upkeep.

Here’s how they cut costs:

• Small size - Most are between 300 and 600 square feet. That means less material, less labor, and less heating.
• Simple design - No vaulted ceilings, no custom cabinetry, no multi-level floors. A single-story rectangle with a gable roof is the most cost-effective shape.
• Local materials - Instead of shipping steel beams from Germany, use timber from nearby forests. In Ireland, timber frame kits from local suppliers cost 40% less than imported prefab systems.
• Reclaimed materials - Old bricks, salvaged windows, second-hand doors - these aren’t just green, they’re cheap. One builder in County Clare used reclaimed oak beams from a 19th-century barn and saved €8,000 on framing.
• No basement - Digging a basement adds €20,000-€40,000 to the cost. Most eco-cottages sit on a concrete slab or screw piles, which are faster and cheaper.

Materials that keep costs low - and the planet healthy

It’s not just about size. The materials you pick make a huge difference in both price and environmental impact.

Here are the top five affordable, sustainable materials used in modern eco-cottages:

1. Timber frame - Fast to assemble, renewable, and excellent insulation when paired with hemp or sheep’s wool. A timber frame kit for a 400 sq ft cottage costs around €12,000-€18,000.
2. Straw bale walls - Yes, actual straw. Packaged tightly, plastered over, and sealed, they’re cheaper than brick and have better insulation than most modern walls. Cost: €25-€40 per square meter installed.
3. Recycled steel roofing - Lasts 50+ years, sheds snow easily, and costs half as much as tiled roofs. Many Irish builders use it because it’s the only roof that survives Atlantic storms without constant repairs.
4. Clay plaster - Breathable, non-toxic, and made from local soil. It’s cheaper than drywall and doesn’t need painting. One builder in Wicklow used clay from his own land - free.
5. Reclaimed windows - Double-glazed windows from demolished Victorian houses cost €150 each. New ones? €800 each. And the old ones often have better seals than modern budget windows.

One couple in Galway built their 450 sq ft cottage using 80% reclaimed or locally sourced materials. Total cost: €52,000. They didn’t hire an architect. They used free plans from the Irish Sustainable Building Network.

Off-grid systems that save money long-term

Building cheap doesn’t mean living rough. The smartest eco-cottages cut utility bills to near zero - and that’s where real savings kick in.

Here’s what most people install:

• Solar panels - A 2kW system (enough for lights, fridge, and charging phones) costs €3,500 installed. With Irish grants, you can get €1,800 back. Payback time: under 5 years.
• Composting toilet - No water needed, no septic tank. Costs €1,200. Saves €10,000+ over 20 years compared to a conventional sewer system.
• Wood stove - A good one costs €1,500. Burn locally sourced logs - your heating bill drops to €0. In winter, you might spend €100 a year on firewood.
• Rainwater harvesting - A 1,500-liter tank and basic filter cost €600. Enough for washing, gardening, and flushing the toilet.

One woman in Donegal lives in a 380 sq ft cottage with no grid connection. Her total annual utility cost? €48. That’s less than your phone bill.

What you shouldn’t skimp on

Building cheap doesn’t mean building flimsy. There are three things you should never cut corners on:

1. Insulation - Skip this, and your cottage will be cold in winter and hot in summer. Use at least 200mm of natural insulation (hemp, sheep’s wool, or cellulose). It’s not the cheapest upfront, but it saves money every month.
2. Waterproofing - Ireland rains 200+ days a year. A bad roof or poorly sealed foundation leads to mold, rot, and repairs that cost 10x what you saved.
3. Foundations - Don’t try to save €2,000 by using concrete blocks instead of a proper slab. Soil movement in Ireland’s clay-heavy ground will crack your walls in 3 years.

One builder in Kerry spent €10,000 on insulation and waterproofing. He saved €15,000 in repairs over five years. That’s not a cost - it’s insurance.

Who’s building these cottages - and why

It’s not just retirees or hippies. In 2025, the fastest-growing group building eco-cottages in Ireland are young professionals in their 30s. They’re tired of renting, sick of mortgage brokers, and don’t want to spend 30 years paying for a house they’ll never fully own.

They’re building these cottages because:

• They want to live debt-free
• They care about carbon footprint
• They value quiet and self-reliance over square footage
• They’ve seen friends get crushed by property taxes and energy bills

Some use the cottage as a full-time home. Others build it as a weekend retreat - and rent it out on Airbnb. A well-built eco-cottage in rural Ireland can earn €500-€800 a week in peak season. That pays for itself in under a year.

Where to start if you want to build one

If you’re serious, here’s your first step list:

1. Find land - Look for plots with existing access roads and no planning restrictions. Rural areas in Mayo, Sligo, and Leitrim have cheaper land and more relaxed rules.
2. Use free plans - The Irish Sustainable Building Network offers 15+ free cottage designs online. No need to pay an architect.
3. Get a basic planning permission - Most eco-cottages under 40 sq m don’t need full planning if they’re not in protected areas. Check with your local council.
4. Source materials locally - Join Facebook groups like ‘Reclaimed Building Materials Ireland’ or visit salvage yards in Cork, Limerick, and Waterford.
5. Build in phases - Do the foundation and shell first. Add insulation, windows, and systems later. This spreads out the cost.

One man in Wexford built his cottage over 18 months, working weekends and evenings. He spent €55,000 total. He owns the land. He has no mortgage. He heats his home with logs from his own woodlot. And he sleeps better than he ever did in his Dublin apartment.

Final thought: It’s not about being poor - it’s about being free

The most affordable home to build isn’t the cheapest one. It’s the one that gives you freedom - from rent, from debt, from energy bills, from the rat race. An eco-friendly cottage doesn’t ask for much. It just asks you to live simply. And in a world that’s never stopped pushing for more, that’s the real luxury.