Near-zero energy buildings, known as nZEB, represent a concrete step towards the transformation to sustainable and energy-efficient solutions, which are increasingly needed due to the climate crisis and increasing energy consumption.
The meaning of nZEB
NZEB stands for Nearly Zero-Energy Building. These are, in fact, buildings designed to minimise energy consumption and generate a significant part of their energy needs through renewable sources produced on site or nearby. The concept of nZEB is closely linked to sustainability and efficiency, as these buildings significantly reduce environmental impact and operating costs. Thus, an nZEB building represents a future-oriented building model that contributes to reducing CO₂ emissions and conserving resources.
Incide Engineering, which is active in the field of sustainable design, participated in numerous nZEB projects, contributing to the realisation of innovative and environmentally friendly structures.
EU regulation on nZEB public buildings
There’s current legislation governing this issue. In particular, European Directive 2010/31/EU mandated that:
- all new buildings publicly owned or used by public bodies must be nZEB, as of 31 December 2018;
- for private buildings, this obligation started on 31 December 2020.
In Italy, the transposition of European regulations took place with Legislative Decree 192/2005 and subsequent updates, which set specific energy efficiency requirements for public buildings.
The criteria for an nZEB building
To be classified as nZEB, a building must meet specific regulatory and technical requirements, which vary according to local and regional regulations. The main requirements include:
- Thermal insulation: a highly insulating building envelope (walls, roof, floors, windows) that minimises heat loss.
- High-efficiency plant systems: such as controlled mechanical ventilation (VMC) with heat recovery, which ensures indoor air quality with minimal energy expenditure.
- Renewable energy sources: the energy required must be generated mainly from renewable sources, such as photovoltaics or solar thermal energy.
- Control and monitoring systems: to optimise and manage energy according to actual needs, reducing waste and optimising efficiency.
- Water and soil reuse and management: an increasingly strategic aspect, especially in buildings subject to minimum environmental criteria.
These requirements have been defined at European level to respond to greenhouse gas emission reduction targets, promoting a new standard for building construction.
At the European level, Directive 2010/31/EU mandated that, from 2020, all new buildings must be nZEB. In Italy, this legislation has been in force since 2019 for public buildings, and since 2021 for all new private buildings. However, there are exemptions for certain types of buildings, such as historic buildings or those subject to landscape constraints, where the structural modifications necessary to meet nZEB requirements may be difficult or impossible to implement.
The aim is to incentivise the construction sector to move towards innovative and sustainable energy solutions, ensuring the achievement of greater efficiency and reduced environmental impact.
Design phases of an nZEB building
The design of an nZEB building requires an interdisciplinary approach that considers the building’s life cycle and involves various professionals. The main phases include:
- Preliminary analysis: site and local climate assessment, building orientation, natural ventilation and environmental conditions, to optimise energy efficiency.
- Building envelope design: materials and construction solutions that provide advanced thermal insulation to reduce energy needs for heating and cooling.
- Plant design: integration of efficient heating and cooling systems, such as heat pumps and controlled mechanical ventilation, with heat recovery.
- Integration of renewable energy sources: installation of photovoltaic and solar thermal systems for renewable energy production.
- Monitoring and automation systems: technologies for consumption control and continuous optimisation of energy performance.
These steps make it possible to design buildings that not only meet energy requirements, but also ensure the comfort and healthiness of the environment.
A strong and constant integration between the various disciplines is necessary to ensure that all aspects are adequately assessed and considered, reducing as far as possible changes and variations that result in impacts on design timescales (and consequently costs).
Technologies and strategies for the design of nZEB buildings
The realisation of an nZEB building is based on specific technologies and strategies that contribute to the reduction of energy consumption and the use of renewable sources. Some of the most popular solutions include:
- Photovoltaic and solar thermal panels: for the production of electricity and hot water from solar energy.
- Advanced thermal insulation: the use of materials such as rock wool or expanded polystyrene, which reduce heat loss and improve the efficiency of the building envelope.
- Controlled mechanical ventilation with heat recovery: for continuous air exchange without heat loss, thus improving indoor air quality and reducing energy consumption.
- LED lighting systems and presence sensors: to reduce consumption by adapting lighting to the actual needs of the occupants.
- Heat pumps: which harness thermal energy from the environment to efficiently heat or cool spaces.
- Geothermal: one of the most promising sources for the use of heat pumps is the ground or heat exchange with surface water or groundwater.
- Water reuse: the water resource is becoming increasingly important, both in terms of the correct management of the rainfall regime, and considering the need to reserve drinking water for human uses by allocating reclaimed water to less noble uses.
These technologies are key to making nZEB buildings efficient and sustainable, contributing to a lower environmental impact and a more responsible use of resources.
NZEB projects by Incide Engineering
Incide Engineering participated in several projects that comply with nZEB criteria, confirming its commitment to the design of sustainable, low environmental impact buildings.
One of the most significant projects is the Antonio Vivaldi and Renato Simoni school complex in Albaredo d’Adige, (IT). For this project, in partnership with Vittorio Grassi Architects, Incide took care of the structural and plant design, construction management, fire prevention and safety, adopting solutions that meet the current CAM (Minimum Environmental Criteria).
The building was designed to minimise energy consumption, integrating a photovoltaic system on the roof that covers the building’s entire energy requirements, making it classifiable as nZEB-20% (Nearly Zero Energy Building). This realisation exemplifies Incide’s integrated approach to sustainable, future-oriented architecture.
Another project carried out by Incide in the last period, and for which LEED certification was also achieved, is Hangar PG109 at Ciampino Airport (RM), which exploited the advantages of BIM to ensure integrated control and management during all phases of the project. Again, the structure was designed to meet nZEB standards, with solutions to reduce consumption and CO₂ emissions, aligning with European and national directives on energy efficiency.
Another outstanding example that embodies the principles of nZEB buildings is the Linate Prime Terminal, an infrastructure dedicated to private and business aviation. In this project, Incide Engineering played a key role, taking care of the structural and plant design to ensure state-of-the-art energy efficiency. The Terminal was built according to Nearly Zero-Energy Building criteria, focusing on plant technologies that maximise energy savings and minimise CO₂ emissions. Controlled mechanical ventilation systems, solar panels and state-of-the-art insulation materials are just some of the solutions adopted to align with nZEB standards. This project not only meets nZEB standards, but also represents a concrete example of how near-zero energy buildings can be realised in complex contexts such as an airport terminal. With innovative technical solutions and an iconic design, the Linate Prime Terminal demonstrates that it’s possible to combine sustainability, energy efficiency and architectural quality, confirming itself as a model for the future of infrastructures.
These projects demonstrate how the adoption of nZEB strategies can create innovative, low environmental impact buildings with a high level of comfort for occupants.
nZEB buildings represent the future of sustainability in the construction sector. Designing according to these standards means not only constructing efficient and comfortable buildings, but also actively contributing to the reduction of global emissions. Through the adoption of advanced technologies, integrated consumption management and collaboration between different disciplines, the construction sector can become a benchmark for sustainability.
Incide Engineering continues to be a pioneer in this field, developing projects that embody the principles of nZEB and demonstrate that building sustainably is possible and beneficial to the environment and future generations.
