HEART: Holistic Energy and Architectural Retrofit Toolkit: toolkit for the comprehensive energy retrofit of buildings

HEART addressed the need to undertake deep retrofits of multi-family residential buildings from the second half of the 20th century, characterized by very low energy performance. The geographic focus was on central and southern Europe, where the moderate climate affects not only heating demand but also overheating and cooling problems, aggravated by climate change and the energy transition.

The objectives of the project were:

• Develop systemic, cost-optimal solutions for energy retrofit, reducing installation time by at least 30% compared with usual construction practice and ensuring payback periods of less than 15 years.
• Systemically integrate subcomponents of different kinds: envelope solutions, technical systems, renewable energy sources, and building energy management systems.
• Turn existing buildings into smart buildings, aligned with the nearly zero-energy standard.
• Support decision-making during the planning of the intervention and facilitate the financing of energy efficiency.

The areas around which HEART was structured were:

• Cloud platform: the core of the system, which concentrated the operational and management logic to support decision-making in planning and construction, as well as energy performance improvement and monitoring during operation.
• Envelope technologies and technical systems: thermal insulation and window solutions that reduced thermal loads, together with a heat pump, fan coil units, thermal and electrical storage, an integrated photovoltaic roof tile, and IoT devices.
• Smart grid interaction: optimization of energy flows within the building and between the building and the smart grid, with data exchange and active participation of stakeholders.

CTIC's participation focused mainly on the design and development of the communications architecture of the IoT devices within the building, ensuring the flow of data from the sensors and equipment to the building energy management system (BEMS). Among the technologies used was narrowband IoT (NB-IoT).

The toolkit was validated through the complete retrofit of two demonstration buildings, in Italy and France, achieving savings of between 80% and 90% in heating, cooling, and domestic hot water production.