Guide contents 📖
1. Introduction to the study
Faced with the growing challenges of energy efficiency, driven both by new regulations and potential financial savings, Sinteo is capitalizing on the energy and carbon data obtained from energy audits of commercial and residential buildings through our new in-house tool.
Our in-house benchmark does not simply collect the overall energy consumption of buildings; it also takes into account all the factors that influence a building's energy and carbon performance (year of construction, typology, types of equipment, etc.), and enables consumption to be analyzed by item (HVAC, lighting, DHW, etc.).
What's in it for me?
Evaluation of the average consumption of a building
Depending on its date of construction/renovation, location, equipment, etc.
Know the consumption of each item
Heating, air conditioning, ventilation, lighting, office equipment, servers, etc.
Compare consumption data
According to different criteria such as type of housing, offices, hotels, etc.
2. What you need to know from the benchmark - key figures - focus on office buildings
This blog post therefore focuses on data relating to office buildings, i.e. 205 assets to date, spread across mainland France.
2.1 -> Breakdown of consumption by item
Figure 1: Breakdown of consumption by item - offices - all years combined (in kWhEF/m²)
Analysis
Unsurprisingly, heating is the biggest consumer of energy in office buildings. On average, it accounts for 34% of a site's consumption, with 56 kWh/m² (all energy types combined).
As a result, the greatest potential for energy savings generally lies in this area. This is achieved first and foremost through energy-saving measures (optimized setpoint temperatures, adapted timetables, etc.), followed by energy-efficiency measures (installation of heat pumps, insulation of networks and buildings, heat recovery via double-flow ventilation, proper regulation of equipment, etc.).
However, to achieve significant energy savings, comprehensive renovation is far more effective than piecemeal improvements.
Air conditioning is the second largest consumption item, accounting for an average of 12% of an office building's consumption. This item is set to increase, given climate change and the undersizing already observed in some buildings.
In addition to its consumption, air conditioning has an impact on urban temperature increases (by releasing hot air outdoors), as well as on the potential release into the atmosphere of refrigerants with significant warming potential.
> Read our CRREM blog post
Lighting comes third, with 11% of consumption on average. Lighting fixtures in commercial properties are gradually being replaced by LEDs, the most energy-efficient technology available today. Good lighting management can also generate savings (presence detection for intermittent premises, timetables for switching off, etc.).
On average, office IT accounts for 10% of consumption. It is important not to underestimate standby power consumption for computers and other equipment.
HVAC (Heating Ventilation Air Conditioning) auxiliaries , which include circulation pumps and emitters (fan coil units, cassettes, etc.), account for 9% of consumption on average. The latter are correlated with the use of heating and air conditioning within a building.
Ventilation, which includes the consumption of sanitary extractors and office Air Handling Units (AHUs), accounts for an average of 8% of consumption. In the event of poorly-adjusted air renewal rates, an AHU can generate significant consumption linked to fans and heat loss (air renewal). Double-flow ventilation with efficient heat recovery can reduce heating consumption.
For a more detailed analysis, the benchmark can also be used to compare consumption items by year of construction.
2.2 -> Consumption trends by item
The graph above represents each building by a point, allowing us to distinguish the differences between them. Heating and air-conditioning consumption varies considerably from one building to another, due to the different production systems (boiler, heat pump, joule effect, etc.) as well as variations due to regulation (presence of a BMS/CGT, absence of regulation, etc.).
This variability underlines the importance of energy audits to identify the specific features of each building.
An analysis of the graph for all years shows that :
Median at 85 kWh/m²
2nd consumer: offices built in the 2000s
Median at 49 kWh/m²
3rd consumer: offices built between 2010 and 2020
Median at 30 kWh/m²
These results show a downward trend in energy consumption for heating in more recent buildings. This is due to the performance of equipment and building insulation, which has improved over the years and through thermal regulations. This trend will continue with the RE 2020 regulation.
Median at 17 kWh/m²
2nd consumer: Haussmann-style offices
Median at 15kWh/m²
3rd consumer: offices from the 2010s-2020s
Median at 14 kWh/m²
For air-conditioning, however, offices from the 2000s consume slightly more than other types. This can be explained by the greater inertia of Haussmann-style buildings and the greater glazed surface area of offices built in the 2000s.
2.3 -> Comparison of different types of energy used
These figures need to be qualified with regard to the location of the assets audited during the campaigns, many of which are located in the Ile-de-France region, where urban networks are widely deployed. In fact, according to SDES, Bilan énergétique de la France, commercialized heat represents only 4% of tertiary energy consumption in 2022.
| Consumption (enkWhEF) | CO2 equivalent |
|---|---|
|
1 kWhEF electricity 1 kWhEF gas 1 kWhEF urban grid |
0.064 kgreqCO2 0.227 kgreqCO2 0.171 kgreqCO2 (for CPCU, Paris urban network) |
Sources :
- Electricity/gas: Arrêté méthode of April 10, 2020, published as part of the Eco-Energie Tertiaire program.
- District heating and cooling networks: Order of March 16, 2023, taking into account the values in the CO2 content "LCA" column (also known as "Location Based").
Depending on the sites audited, feasibility and regulations, different heating systems may be recommended, principally the installation of heat pumps or connection to the district heating network.
Regulatory reminder
If an asset is located in a priority development zone, connection to the district heating network is mandatory in the event of major renovation work on production systems, although exceptions are possible. This concept is enshrined in the French Energy Code.
Urban networks, their technical characteristics and priority development zones are listed on the France Chaleur Urbaine website.
3. In conclusion
Analysis of consumption by item provides a basis for identifying opportunities for improvement and energy savings. The benchmark results reveal trends that can guide strategic decisions regarding the renovation and optimization of energy systems.
This substantial wealth of data collected will enable us to carry out further analyses in the future, which will in turn take into account geography, carbon impact and a host of other factors.
To be continued...
4. Glossary
HVAC auxiliaries: HVAC (Heating, Ventilation and Air Conditioning) auxiliaries are secondary equipment that contribute to the operation of the main HVAC systems. HVAC auxiliaries include fans, pumps and other equipment that support the operation of HVAC systems, without being the main components. Their role is essential to ensure the circulation of air and fluids, as well as the control of HVAC systems.
Primary energy: "Primary energy is the totality of unprocessed energy products, whether used directly or imported. These are mainly crude oil, oil shale, natural gas, solid mineral fuels, biomass, solar radiation, hydraulic energy, wind energy, geothermal energy and energy derived from uranium fission", INSEE definition.
Final energy: "Final or available energy is the energy delivered to the consumer for final consumption (gasoline at the pump, electricity in the home, etc.). This is the basis on which energy suppliers draw up their invoices", INSEE definition.
Inertia: A building's thermal inertia is its capacity to store and release heat over time. It depends mainly on the mass and thermal properties of the materials used in construction.
RIE: Restaurant inter-Entreprise