Energy Audits as a tool for the energy retrofitting of schools
TerrAria carried out 10 Energy Audits on school buildings owned by the Municipality of Cesano Maderno, with the aim of analysing their energy consumption and identifying the most promising energy retrofit measures. The municipality, located in the Province of Monza and Brianza and with a population of approximately 40’000 inhabitants, features a diverse school building stock representative of the different construction typologies found across the area.
The schools analysed include:
- Primary School “Martin Luther King”
- Primary School “Gianni Rodari”
- Primary School “Alessandra Negri”
- Lower Secondary School “Salvo D’Acquisto”
- School “Ex-Fermi”: CIOFS and UNITRE
- Primary School “Luigi Minotti”
- Gym of Primary School “Luigi Minotti”
- Lower Secondary School “Galileo Galilei”
- Nursery School “Maria Montessori”
- Nursery “Il Piccolo Principe”
In accordance with UNI/TR 11775:2020 (“Energy audits – Guidelines for energy audits of buildings”), UNI 16247-1:2022 (“Energy audits: general requirements”) and UNI 16247-2:2022 (“Energy audits: buildings”), an Energy Audit is a detailed technical analysis that allows the estimation of a building’s energy demand.
The process is based on the collection of data related to construction and system characteristics, combined with on-site inspections aimed at verifying the actual condition of the building and its systems. The collected information is processed through energy models developed using dedicated software to represent the building’s behaviour; among these, the use of Termolog is highlighted, as it enables detailed energy simulations compliant with current regulations.
This approach makes it possible to identify critical issues and propose energy efficiency measures, such as thermal insulation or system replacement. For each solution, costs, energy savings, and payback times are assessed, and the results are consolidated into a detailed technical report.
The analyses carried out made it possible to define a comprehensive understanding of the schools’ energy performance, providing support to the Municipal Administration in planning targeted interventions aimed at improving performance and reducing consumption. Energy Audits also represent a key tool for accessing incentives under the Conto Termico, as they are often a mandatory document to be included in the application process.
The decision to analyse and assess the current condition of the schools was also driven by the fact that these buildings are eligible for up to 100% funding through the Conto Termico, a national incentive scheme supporting energy efficiency measures and the production of thermal energy from renewable sources in buildings.
The schools analysed belong to different historical periods but mostly date back to the 1970s; consequently, external walls are generally made of heavy masonry without insulation, and windows are often characterised by metal frames without thermal break.
From an energy perspective, most of these school buildings fall within energy class D. Exceptions are represented by schools connected to district heating systems, which, thanks to the contribution of renewable sources, achieve higher energy classes despite envelope-related deficiencies.
In particular, the development of these Energy Audits made it possible to identify the “S. D’Acquisto” School as the primary target for energy efficiency interventions. Despite having a relatively good energy class due to its connection to district heating, the building required improvements to the envelope; therefore, the planned activities included insulation of external walls and roof, as well as window replacement.
THE ROLE OF TERRARIA
The activities carried out by the TerrAria team, coordinated by the Certified Energy Manager Giuseppe Maffeis, for the preparation of the Energy Audits of the 10 schools in the Municipality of Cesano Maderno can be summarised as follows:
- Preliminary data collection and analysis: acquisition of documentation provided by the Municipality of Cesano Maderno, with particular focus on the geometric, construction, and system characteristics of the buildings, together with available technical documentation such as DWG drawings, boiler plant logbooks, and historical data on energy consumption and expenditure over the past 3 years.
- On-site inspection: site visits for each school building and its systems, aimed at verifying the actual condition of the assets, identifying potential critical issues, and integrating the collected information. In particular, during inspections, the type and thickness of opaque structures, dimensions of windows and doors, characteristics of the boiler plant, and type and capacity of emission systems are recorded.
- Modelling: development of the building energy model using dedicated software such as Termolog and CENED, with the aim of simulating its energy behaviour and assessing performance under different operating conditions. The outcome enables the simulation of an Energy Performance Certificate, defining the school’s energy class and its global performance index.
- Calibration: comparison between model results and actual consumption data provided by the Municipality of Cesano Maderno, followed by analysis of any discrepancies and optimisation of parameters to ensure simulation reliability. This process refines the model by reducing gaps between simulated and real behaviour, improving its overall accuracy.
- Energy efficiency measures: following model calibration, potential improvement measures are identified and assessed by analysing energy savings, costs, available incentives, and payback times. Measures may involve the building envelope (insulation of opaque structures and window replacement), thermal systems (heat pump heating systems, solar thermal systems, and heat pump water heaters), and electrical systems (relamping and photovoltaic systems), with the goal of improving overall energy performance.
- Report preparation: drafting of the final report summarising the analysis of the current state of the schools, identification of main energy criticalities, and proposal of improvement measures, including related techno-economic evaluations.
The preparation of these Energy Audits enabled the Municipality of Cesano Maderno to gain a comprehensive overview of the current condition of its school buildings and, at the same time, to identify those requiring the most urgent energy efficiency interventions. This made it possible to define intervention priorities and guide decision-making toward the most effective solutions in terms of energy savings and economic feasibility.
