Understanding GHG emissions related to real estate

Understanding the role of housing in greenhouse gas emissions

In France, the residential sector accounts for nearly a quarter of greenhouse gas (GHG) emissions. A large part of these emissions come from heating, daily energy consumption, and hot water production. These factors are closely linked to the design of homes, their insulation, and the energy sources used, whether gas, electricity, or fuel oil.

Older houses and dwellings, which are often poorly insulated, are responsible for high energy consumption, leading to an increase in carbon emissions into the atmosphere. Conversely, newer, better-designed dwellings offer superior energy performance, resulting in a significant reduction in their GHG rating. This distinction between old and new dwellings illustrates the importance of modernizing the housing stock in order to achieve national carbon neutrality targets.

ADEME points out that for every building or home, reducing energy consumption can be achieved through simple actions: maintaining your heating system, insulating your attic and walls, or opting for renewable energy sources. These individual actions, multiplied on a national scale, directly contribute to reducing greenhouse gases, while improving the comfort and value of your home.

The GHG Balance Sheet: a snapshot of greenhouse gases

Before taking any steps to reduce greenhouse gases, it is essential to understand where they come from. The GHG balance sheet is a key tool for measuring the amount of greenhouse gases associated with each activity related to a home: heating, hot water production, building materials, travel, etc.

This calculation is based on three scopes, which enable the origin of emissions to be identified:

• Scope 1 for direct emissions (such as those related to heating or gas combustion);
• Scope 2 for indirect emissions from electricity used;
• Scope 3 for all other indirect impacts, including those related to the manufacture of materials, their CO2 emissions linked to transport, or their maintenance over time.

This tool, based on the Base Carbone® andADEME methodology, helps industry players to better identify sources of impact and develop credible reduction strategies.

From measurement to action: steering the course toward more sustainable housing

Once the measurement has been established, the next step is to define a clear roadmap. This is where the concept of a low GHG trajectory comes in, reflecting an actor's ambition to gradually reduce its emissions over time. This planning is based on analysis and simulation tools that enable the visualization of possible progress according to different scenarios.

The success of this initiative depends on a structured approach:

1. Identify the primary sources of emissions (heating, hot water, materials, gas, etc.);
2. Prioritize actions according to their reduction potential;
3. Implement solutions tailored to the local context and available resources.

A comprehensive and collaborative approach: the Decarbo’Solution® triptych

Reducing the footprint of housing-related activities requires consideration of the entire value chain. Materials, suppliers, construction companies, local authorities, and public administrators all contribute, directly or indirectly, to greenhouse gas emissions.

To address this challenge, GCI's Decarbo'Solution® initiative offers a three-pronged integrated approach:

• Decarbo’Supply® promotes collaboration between clients and their suppliers in order to assess the environmental impact of the goods and services used. This method is based on transparency and the joint development of action plans aimed at limiting waste related to purchases and materials.
• Decarbo’Target® supports long-term planning. Using simulation tools, it helps establish a coherent roadmap that is tailored to the realities on the ground and complies with international measurement and monitoring standards.
• Decarbo’Tender® introduces a new way of integrating environmental considerations into calls for tenders. By identifying the least polluting service providers, it contributes to more responsible selection and the spread of virtuous practices within the market.

These three areas work together: measure, engage, then improve.

Renovating, innovating, and cooperating for sustainable development of the residential housing stock

Towards more energy-efficient homes: renovation as a priority

Long perceived as a simple measurement tool, the EPC has now become a real driver for renovation. By identifying the GHG class and energy class of each home, it not only allows the initial situation to be assessed, but above all enables a clear path towards modernization to be defined. This assessment is now at the heart of public policy and local strategies, as it guides priorities for action and long-term investment.

The challenge goes beyond mere regulatory compliance: it is about using the EPC as a starting point for transforming the residential housing stock. The information it provides on heat loss, materials, and equipment can be used as indicators for action. It makes it possible to identify the most vulnerable homes, plan high-potential renovations, and track progress over time.

This approach makes the EPC a strategic tool for the transition to more energy-efficient housing. It enables households and public authorities to prioritize insulation, system modernization, the choice of sustainable materials, and the use of thermal efficiency solutions. Public aid, provided in particular byADEME, encourages these initiatives by supporting renovation projects and initiatives aimed at improving the thermal quality of homes.

Beyond its technical role, the EPC acts as a cultural catalyst. It changes the perception of housing: from a simple material asset, it becomes a space of collective responsibility, where each improvement contributes to reducing GHG emissions and improving the living environment.
Renovation is no longer an isolated individual effort, but a shared approach that contributes to the construction of a more sustainable, balanced, and forward-looking housing model.

Innovation as a driver of sustainable housing

The future of housing lies in a new generation of low-carbon practices and materials. The challenge is no longer limited to improving a home's GHG rating, but to designing spaces that blend harmoniously into their natural surroundings while limiting their overall footprint.

Thermal innovations play a key role in this evolution. High-performance insulation, solar control glazing, green roofs, and breathable walls reduce energy requirements while ensuring greater indoor comfort. These advances are combined with eco-intelligent management systems that can automatically adjust temperature, ventilation, and lighting according to the actual needs of occupants.

The materials used are also evolving: certified wood, raw earth, and bio-based insulation materials now play a central role in construction and renovation. Their function is not limited to strength or aesthetics: they actively contribute to thermal regulation and heat loss reduction.

Finally, the widespread use of EPCs and environmentallabels increases transparency for individuals. When selling or planning to buy a property, the energy efficiency rating becomes a key benchmark, encouraging everyone to choose the most energy-efficient homes that are the most respectful of the ecosystem.

Innovation is therefore not only measured in terms of technology, but also in the way buildings are reimagined as living organisms: places that breathe, adapt, and contribute to a sustainable balance between human comfort and environmental preservation.

Working together for a sustainable path forward

The success of an eco-responsible approach depends on cooperation between the various players in the sector: owners, large companies, associations, local authorities, and technical experts.
Each has a specific role to play in this joint effort:

• Homeowners are committed to upgrading their homes;
• Companies develop appropriate thermal and technical solutions;
• Local authorities support and finance environmental programs;
• Experts such as GCI provide reliable GHG calculation and assessment tools to guide decisions.

This collective organization creates a virtuous circle where reducing GHG emissions becomes a shared responsibility. It is based on understanding EPC data, correctly readinglabels, and gradually integrating more resource-friendly practices.

The transformation of buildings is therefore a societal issue that goes far beyond technical considerations. It involves a cultural shift, a more sustainable vision, and a desire to harmonize comfort, simplicity, and environmental responsibility.

Reducing greenhouse gas emissions in the residential sector is no longer just a regulatory requirement: it is a genuine social project. Every home, every energy performance rating, and every energy label now reflects a collective and measurable responsibility in the fight against global warming.

Supported by public policies and ADEME tools, initiatives are multiplying to help households, businesses, and communities adopt more sustainable practices. These guidelines provide a clear and accessible framework, enabling everyone to take action at their own level while participating in a national transformation process.

Energy-efficient renovations, the use of sustainable materials, and the adoption of digital management solutions are evidence of a profound change that is already underway. Beyond technical performance, it is our way of living, our conception of the value of a home, and our idea of comfort that are evolving.

Thanks to structured methodologies and innovative carbon measurement systems, industry players can now track their progress with rigor and transparency. These approaches combine scientific rigor, innovation, and a sense of community to build a more sober, smarter, and truly sustainable housing model.

Because well-designed housing today means a more balanced planet tomorrow.