Building the city of tomorrow: the keys to sustainable construction and low-carbon architecture

By 2050, nearly 70% of the world’s population will live in cities. In the face of the climate emergency, the question is therefore no longer whether we should build sustainably, but how we can transform our buildings into carbon sinks.

The entry into force of RE2020 marks a major turning point in the low-carbon construction sector: sustainable architecture is no longer limited to energy performance; it requires the use of low-carbon and bio-based materials capable of reducing environmental impact right from the construction stage.

Discover how eco-friendly timber cladding is becoming a key solution for reconciling sustainable construction, energy efficiency, regulatory requirements and HQE sustainable building certifications.

Key takeaways: 

• RE2020 incorporates the carbon footprint across the entire building lifecycle
• Bio-based materials are essential for achieving climate targets
• Sustainable timber cladding combines aesthetics, performance and a low carbon footprint
• Environmental labels promote low-carbon projects
• Timber is a strategic lever for sustainable urban architecture

Coming into force in 2022, RE2020 (the 2020 Environmental Regulations) marks a significant shift in building regulations. It is no longer limited to energy performance alone: it now aims to reduce the overall carbon footprint of buildings, whilst improving occupant comfort.

RE2020 is based on three main objectives:

• Reducing energy consumption,
• Reducing greenhouse gas emissions, starting from the construction phase,
• Ensuring greater comfort in summer, in the face of increasingly frequent heatwaves.

It applies mainly to new buildings, with progressive requirements that become stricter over time to support the sector’s growing expertise.

LCA for buildings and IC Construction: quantified indicators at the heart of RE2020

Life Cycle Assessment (LCA): the foundation of the carbon approach

The RE2020 introduces a holistic approach through the Life Cycle Assessment (LCA) of buildings. This assesses environmental impacts throughout the building’s entire life cycle (50 years for residential buildings), taking into account:

• The extraction of raw materials,
• The manufacture of products,
• Their transport,
• The use phase,
• And end-of-life (demolition, recycling).

This method goes beyond the ‘energy’ perspective to fully integrate the carbon footprint of materials.

The Construction IC: a carbon threshold not to be exceeded

Introduced by the RE2020 environmental regulations, the Construction IC is one of the key indicators derived from Life Cycle Assessment (LCA). It measures CO₂ emissions associated with materials, equipment and the construction site, expressed in kg CO₂ equivalent per m² over 50 years.
The regulatory thresholds are progressive and become stricter over time.

Since 1 January 2025, the maximum values to be met for new buildings are:

• Detached houses: 530 kg CO₂e/m²
• Multi-occupancy dwellings: 650 kg CO₂e/m²

These thresholds represent a reduction of 12 to 17 per cent compared to those applied since 2022, and further reductions are already scheduled for 2028 and 2031, further reinforcing the appeal of low-carbon solutions.

In practical terms, the choice of materials becomes crucial: structure, facades, cladding, insulation and finishes have a direct impact on compliance with the IC Construction threshold.

And what about renovation?

To date, RE2020 does not set a mandatory IC Construction threshold for renovation projects. However:

• LCA and environmental data are increasingly used in voluntary certification schemes and low-carbon initiatives,
• Project owners are already anticipating these trends to improve the environmental value of their property portfolio,
• Materials with verified FDES (Environmental Data Sheets) are a key asset in these projects.

The central role of FDES and the INIES database

The calculation of the Construction Carbon Footprint is based on FDES (Environmental and Health Declaration Sheets), which are available on the INIES database. In the absence of specific FDES, default environmental data – which are much more disadvantageous – are applied.

As such, Sivalbp solutions feature verified individual FDES, enabling:

• A reliable assessment of their carbon footprint,
• Better control of the Construction Carbon Footprint,
• And easier integration into projects subject to the RE2020

Compared to concrete and steel, which are major sources of CO₂ emissions, bio-based materials are emerging as a sustainable solution for reducing a building’s carbon footprint. Their low environmental impact, combined with their technical performance, makes them key contributors to low-carbon construction and compliance with the RE2020 requirements.

Wood: the champion of carbon storage in construction

As the ultimate bio-based material, wood naturally stores the carbon captured by the tree as it grows. This carbon remains sequestered throughout the building’s lifespan.

The result: the carbon footprint of wood in construction is significantly lower than that of conventional materials, whilst offering strength, durability and structural reliability. This is why wood is now establishing itself as a cornerstone of sustainable, low-carbon construction.

Strengthening the circular economy with renewable resources

Sourced from sustainably managed forests (PEFC and FSC certified), wood fully complies with the principles of the circular economy in the construction sector:

• A renewable resource on a human timescale
• Recyclable or recoverable at the end of its life
• A driver of local industries and jobs that cannot be relocated

According to ADEME, the construction sector accounts for nearly 25% of CO₂ emissions in France. To meet climate targets, the use of bio-based materials with FDES certification is becoming a priority for architects and project owners subject to the requirements of RE2020.

Summer comfort: a key driver of sustainable construction

Beyond embodied carbon, bio-based materials play a vital role in the performance of buildings, particularly in the face of increasingly frequent heatwaves.

The building envelope, combining high-performance insulation with sustainable timber cladding, effectively helps to:

• Limit overheating in summer
• Reducing the need for air conditioning
• Sustainably improving occupant comfort

Thanks to its low thermal conductivity, thermal lag and natural breathability, timber plays a key role in energy-efficient construction, suited to current and future climate challenges.

Long confined to a purely protective role, timber cladding is now establishing itself as a key element in architectural design. Combining environmental performance, technical durability and aesthetic appeal, it fully meets the requirements of contemporary projects, whether residential, commercial or urban.
Thanks to industrial advances and innovations in finishes, eco-friendly timber cladding has become a well-controlled, sustainable material that is compatible with urban constraints, whilst retaining its authenticity.

Aesthetic durability: finishes that last without heavy maintenance

To meet the aesthetic requirements of contemporary projects, Sivalbp offers the New Age range, comprising pre-greyed wood stains available in several shades of grey to suit all architectural styles, from multi-occupancy housing to urban infrastructure.

These saturators penetrate deep into the wood, providing long-lasting protection for the fibres without forming a surface film, and deliver a uniform, controlled finish immediately upon application. They then accompany the material’s natural ageing process without any sudden visual changes.

Key benefits:

• Architectural appearance that remains stable over time
• A palette of greys compatible with all architectural styles
• Limited and simplified maintenance
• Better integration of façades into the urban environment

Innovation for low-carbon materials

Innovation in sustainable timber cladding relies on processes that do not involve chemical treatment, aiming to naturally enhance the material’s performance. Sivalbp draws in particular on its recognised expertise in thermostabilised solutions, which improve the dimensional stability and durability of timber simply by raising the temperature, whilst preserving its recyclability and low carbon footprint.

Charred wood, produced through controlled surface carbonisation, represents another approach: it protects the wood without the need for additives and significantly reduces maintenance requirements. Whilst this process requires energy input, its environmental benefits are evident over the entire life cycle, thanks to increased longevity and the absence of chemical treatments.

These solutions position timber cladding as a high-performance, low-carbon and sustainable façade material, suited to the current requirements of sustainable construction.

Environmental labels have become key drivers of performance and differentiation for professionals in the construction industry. They attest to the environmental quality of projects, enhance their long-term value and meet growing expectations regarding sustainable construction.

Environmental performance recognised by the HQE label

Administered by the HQE-GBC Alliance, the HQE Sustainable Building label certifies a comprehensive approach aimed at reducing the environmental impact of buildings whilst improving user comfort. In particular, it promotes:

• Indoor air quality, essential for health and well-being
• Responsible management of construction waste
• The selection of materials with a low environmental impact

Working with a committed supplier such as Sivalbp makes it easier to achieve these objectives, by guaranteeing solutions that comply with the requirements of leading bodies, such as the CSTB, for example. 

For the most ambitious projects, the Effinergie BEPOS (Positive Energy Building) label recognises buildings capable of producing more energy than they consume, thereby enhancing their overall energy performance.

Towards sustainable, high-performance and resilient architecture

Sustainable construction means designing buildings capable of standing the test of time without losing value, thanks to intelligent bioclimatic design and the use of high-quality, robust and durable materials. This approach promotes resilience in the face of climate, energy and regulatory changes, whilst ensuring projects are part of a long-term vision.

Case study – My Lovely Nature detached house, Beaufort-en-Vallée (France - 49)

This residential project perfectly illustrates the principles of low-carbon construction and sustainable architecture. The choice of Sivalbp timber cladding contributes significantly to the building’s environmental performance and comfort:

• Grey Douglas fir timber cladding, sourced from a French species, ensuring a local and responsible supply
• Pre-weathered cladding, for a consistent aesthetic and controlled natural ageing of the timber
• Soléa II profile, with a substantial thickness, offering enhanced stability and excellent resistance to climatic and thermal variations linked to global warming
• Successful integration into the landscape, in perfect harmony with the built and natural environment

Result: a façade that is both attractive and durable, compliant with HQE requirements, with a low environmental impact, and ensuring a high level of thermal comfort, summer and winter alike.

Sustainable timber cladding is now the future of urban façades.
At Sivalbp, we firmly believe that innovation, bio-based materials and environmental performance are the cornerstones of more resilient cities.
Contact us to incorporate eco-friendly timber cladding solutions into your sustainable construction projects.