Bioconstruction: Natural Materials for Your Next Renovation

Bioconstruction has emerged as the preferred choice for conscious renovations, already representing 35% of the renovation market in countries like Spain. This approach to construction, which prioritizes natural, healthy, and low-environmental-impact materials, is proving that it is possible to create beautiful and functional spaces while reducing the ecological footprint by up to 80% compared to conventional methods.

What is Bioconstruction and Why Does It Matter?

Fundamental Principles

• Natural and non-toxic materials: Prevent VOC (Volatile Organic Compound) emissions
• Passive energy efficiency: Design that minimizes the need for active heating and cooling
• Complete life cycle: From sustainable extraction to biodegradability
• Occupational health: Spaces that improve physical and mental well-being

Impact on Health and the Planet

• Conventional homes: Emit up to 5 kg of VOCs per m² annually
• Bioclimatic homes: Zero documented toxic emissions
• Energy savings: 60-80% less energy consumption for heating and cooling
• Carbon footprint: Up to 90% lower throughout the entire life cycle

Star Materials for your 2025 Renovation

1. Natural Insulation

Sprayed Cellulose:

• Origin: Recycled newspaper + boron salts
• Performance: λ = 0.035 W/mK (Better than fiberglass)
• Application: Air cavities, attics
• Cost: €12-18/m² (including labor)

Expanded Cork:

• Advantages: Naturally fireproof, waterproof, elastic memory
• Formats: Rigid panels or granules for filling
• Durability: Guaranteed for over 50 years
• Sustainability: The bark regenerates every 9 years

Wood Fibers:

• Conductivity: 0.038-0.045 W/mK
• Thermal phase: 12-16 hours (ideal for Mediterranean climates)
• Installation: Easily machined semi-rigid panels

2. Natural Wall Coverings

Clays and Alkaline Earths:

• Properties: 70-90% humidity regulation, natural antibacterial properties
• Color palette: 40+ shades of ochre, earth tones, and Minerals
• Application: On plasterboard, brick, or traditional partition walls
• Maintenance: Spot repairs without leaving marks

High-Permeability Natural Plasters:

• Vapor diffusivity: µ <8 (vs. 30-50 for conventional plasters)
• Alkaline pH: Inhibits mold growth
• Extraction: Local quarries with restoration

Mineral and Casein Paints:

• Silicate or lime-based: Zero emissions from application
• Durability: 15+ years indoors
• Cleaning: Water and neutral soap

3. Ecological Flooring and Paving

Low-Fired Clay:

• Firing: 800-900°C (vs. 1200°C for porcelain stoneware)
• Energy saving: 40% less energy in production
• Characteristics: Natural non-slip surface, warm to the touch

Natural Linoleum (Linum + Oleum):

• Composition: Flour of Cork, linseed oil, jute
• Antibacterial: Naturally effective due to linseed oil
• Lifespan: 30-40 years with proper maintenance

Solid Wood with PEFC/FSC Certification:

• Treatments: Vegetable oils and natural waxes
• Installation: Tongue and groove without toxic glues
• Origin: Sustainable forest management within a 200 km radius

4. Joinery and Structural Elements

Wood-to-Wood Windows:

• Double glazing: Argon-filled cavity + low-E glass
• Joinery: Double airtight seal, thermal break
• U-value: Uw <1.2 W/m²K

Laminated Timber Structures:

• Strength: Structurally more efficient than steel or concrete
• Carbon storage: 1 m³ of wood = 1 ton of CO₂ sequestered
• Prefabrication: 70% reduction in construction waste

Phases of a Bioconstructive Renovation

1. Diagnosis and Planning (2-4 weeks)

• Energy Audit: Thermal imaging, leak testing
• Analysis of existing materials: Detection of asbestos, lead, and formaldehyde
• Bioclimatic Design: Study of solar exposure, cross ventilation, and thermal inertia

2. Preparation and Dismantling (1-2 weeks)

• Selective Dismantling: Meticulous separation for reuse/recycling
• Decontamination, if necessary: ​​Safe removal of identified toxins
• Protection of retained elements: Secure packaging and storage

3. Execution (4-12 weeks, depending on scope)

• Installation of thermal envelope: Continuous exterior/interior insulation
• Renovation of installations: Lead-free plumbing, biocompatible electrical wiring
• Natural finishes: Paints, plasters, and flooring as previously described

4. Commissioning (1 week)

• Commissioning: Verification of energy performance and indoor air quality
• Documentation Delivery: User manual, material certificates, and warranties
• Post-construction monitoring: Indoor air quality analysis 3 and 6 months

How to Choose Bioconstruction Professionals

Certifications to Look For

• IEB Bioconstruction Specialist (Spanish Institute of Baubiologie)
• Passivhaus Designer/Consultant for Energy Efficiency
• Expert in Natural Materials (manufacturer-specific courses)

Key Questions for the First Meeting

1. “Can you provide Safety Data Sheets for the materials?”
2. “Do you perform post-construction indoor air quality measurements?”
3. “Do you have verifiable references for similar renovations?”

Financing and Grants Available in 2025

State Rehabilitation Plan

• Direct Subsidies: Up to 40% of bioclimatic renovation costs
• ICO Loans for Sustainable Rehabilitation: Up to €60,000 over 15 years, 1.5% APR
• Personal Income Tax Deduction: 30% of the invested amount (limit €15,000)

Municipal Green Taxation

• Property Tax (IBI) Reduction: Up to 50% for 3 years for energy efficiency improvements
• Reduced Construction Tax (ICIO): 2% tax rate vs. the conventional 4%

Future Trends in Bioconstruction

Innovative Materials

• Fungal Mycelium: Insulation cultivated with agricultural waste
• Low-Cement Artificial Stone: Geopolymers with fly ash
• Nanocellulose: From forestry waste for ultra-resistant panels

Digitalization and Control

• BIM for Rehabilitation: 3D modeling that quantifies environmental impact
• AI Air Quality Sensors: Continuous monitoring of organic compounds
• Blockchain materials: Complete traceability from origin to home

“Renovating with natural materials is not going back to the past, it’s moving towards spaces that take care of us as much as we take care of the planet” — Ana Sánchez, architect specializing in bioconstruction.