Sustainable renovation: environmentally friendly renovations for auctioned properties

You've snagged a house or an apartment at auction, congratulations! But the real added value comes now: with a green renovation that saves energy, increases living comfort, and simultaneously raises the property's value. With clever measures, you benefit doubly: from lower operating costs and from rising demand for sustainable living spaces. This guide shows step by step how to use your renovation budget in an environmentally sensible way and maximize all funding available.

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1 Starting Point: Energy Audit Instead of Gut Feeling

• Building Energy Certificate of the Cantons (GEAK/GEAK+): Measurable basis for building shell, technology, and renovation phases.
• Thermography and Blower Door Test: Reveals thermal bridges and leaks before you open walls.
• Analyze Grey Energy: Use life cycle assessment tools (KBOB recommendations) to guide material selection based on CO₂ footprint.

“Those who measure first renovate more cheaply later and achieve 30% more funding contributions.”

2 The Eco-Priority List: Order is Everything

Level	Measure	Average Funding Rate*	CO₂ Savings
1	Roof Insulation ≥ U-value 0.14 W/m²K	20-30%	⭐⭐⭐⭐⭐
2	Facade Renovation + Window Replacement (Triple Glazing)	20-25%	⭐⭐⭐⭐
3	Heat Pump + PV System > 10 kWp	35-45%	⭐⭐⭐⭐⭐
4	Controlled Ventilation with Heat Recovery > 80%	10-15%	⭐⭐⭐
5	Rainwater Utilization & Grey Water Recycling	up to 8%	⭐⭐

* Average across cantonal programs + federal building program (as of 2025)

3 Material Selection: Less CO₂, More Living Comfort

3.1 Insulation Materials

• Wood Fiber & Cellulose: Excellent summer heat damping, grey energy < 15 kg CO₂/m³.
• Stone Wool ECO Label: Recycled binder, non-flammable (RF1).
• Vacuum Panels (VIP): Ultra-thin, ideal for heritage-protected facades.

3.2 Interior Design

• Clay plaster naturally regulates air humidity → less ventilation energy.
• PVC-free flooring (linoleum, cork) = 80% less area emissions.

4 Combine Renewable Energy Packages

4.1 Heat Pump + PV = "Electricity from the Roof, Heat in the House"

Plan the PV size so that the annual yield ≈ annual energy demand of the heat pump (system size*SCOP/0.75). Direct surpluses into a battery or electric car.

4.2 Solar Thermal for Multi-Family Homes

In multi-family homes, a vacuum tube collector covers up to 60% of the hot water demand, with summer overproduction buffered in storage tanks.

5 Save Water & Improve Microclimate

• Rainwater Tank ≥ 5 m³ for toilets & garden, 40% potable water savings.
• Green Roofs lower roof temperature by 5-7 °C and increase PV efficiency.
• Infiltration Trenches relieve the drainage system and are eligible for funding in many cantons.

6 Financing: Maximize Funding & Tax Deductions

6.1 Funding Sources 2025

• Federal Building Program (CO₂ Levy): Insulation & Heat Generation
• Cantonal Programs (according to MuKEn 2014): Additional contributions for PV and ground probes
• myClimate & EBP: CO₂ compensation fund for major renovations
• Energy Switzerland interest reduction for Minergie-P renovations

6.2 Tax Advantage "Value Preserving"

All renovation costs that maintain the value (e.g., insulation, heating replacement) are immediately deductible. Value-adding measures (extensions, luxury kitchens) can be spread over 5 years, clever planning combines both.

7 Timeline for a Green Complete Renovation

1. Month 1-2: GEAK+, financing & funding applications
2. Month 3-4: Building shell (roof + facade)
3. Month 5: Windows, air tightness test
4. Month 6-7: Heat pump, PV installation
5. Month 8: Ventilation, smart home control
6. Month 9: Final inspection, GEAK re-certification

8 Case Study: From B-Label to A-Energy Winner

The Lutz family purchased a single-family home from the 1980s (GEAK E) in 2023. After a 9-month renovation (221,000 CHF), the property reached GEAK A/A, with heating energy demand dropping by 78%, and solar power covering 110% of consumption. Thanks to funding (72,000 CHF) and tax deductions (19,000 CHF), the net cost burden is only 130,000 CHF. Market value increase: +240,000 CHF.

9 Quick Checklist for Your Sustainable Renovation

1. Book GEAK + thermography.
2. Roof/facade first, technology afterwards.
3. Apply for funding before awarding work contracts.
4. Select CO₂-optimized materials (KBOB lists).
5. Link PV size to heat pump.
6. Plan for rainwater & green roofing.
7. Document deductible tax items.
8. Inspection: Secure blower door & GEAK re-certification.

10 FAQ

Can I renovate step by step and still receive funding?

Yes, with the GEAK+ step plan, measures can be spread over 5 years, and each stage can be billed with funding. Condition: present a comprehensive concept.

Is a battery worth it for a small PV system <6 kWp?

Usually not, priority is given to optimizing self-consumption through a heat pump boiler or electric car. Batteries are sensible starting from 8 kWp.

Which app will help me track the renovation steps?

“Energy Coach CH” (free, iOS/Android) integrates GEAK data, funding deadlines, and CO₂ monitoring.

11 Conclusion: Sustainable Renovation Pays Off Multifold

Eco-friendly renovations transform your auctioned property into an energy-efficient yield marvel. With a clear audit, clever sequencing, and maximum funding, you drastically reduce CO₂ emissions while simultaneously increasing market value. In short: sustainability is not a cost block, but a turbo for long-term profitability, benefiting both your wallet and the planet.