Passive House, Renewable Energy, and Digital Twin: sustainable Design in response to climate emergencies

A passive house is a building designed to be low-energy. Here’s how digital twins support the design of these eco-friendly buildings to address current climate challenges.

Climate change is the defining crisis of our time and it is happening even more quickly than we feared, the need to adopt sustainable design practices has become crucial. With increasing global warming and the urgent need to reduce carbon emissions, the construction industry is evolving towards innovative and responsible solutions. In this scenario, “passive houses” emerge as pioneers of eco-sustainability, representing the tangible future of eco-friendly design.

Consequently, the demand for this advanced form of sustainable design is constantly increasing, bringing with it a growing demand for architects, engineers, and specialists in the design and implementation of such solutions. To address the rising demand for work in passive house design and more broadly in eco-sustainable buildings, acceleration in the research and development of new technologies is needed. In this context, the “Digital Twin” can be an important resource for all professionals. You can start exploring the potential of this technology by using a digital twin software for free.

In this article, we delve into the concept of passive houses and digital twins, and explore how digital twin technology can assist professionals in the design of passive houses.

Software Interface for Creating a Digital Twin – usBIM

What is a Passive House?

A passive house is an extremely energy-efficient dwelling designed to minimize energy consumption for heating, cooling, and ventilation. These houses are built to rigorous standards aimed at achieving a nearly zero-energy balance.
The elements that characterize a passive house include:

Exceptional thermal insulation: The walls, floors, and roofs of a passive house are highly insulated to prevent heat loss in winter and overheating in summer. High-quality insulating materials are used to minimize heat transfer through building surfaces;
High-energy-efficient windows and glazing: Windows and doors feature double or triple glazing, often with special low-emissivity coatings that prevent heat loss and reduce unwanted solar radiation;
Controlled ventilation systems: A controlled mechanical ventilation system (CMV) ensures a constant air exchange without excessive heat loss. This system recovers heat from exhaust air, contributing to heating the fresh air from outside;
Absence of thermal bridges: Thermal bridges, areas where insulation is interrupted, are eliminated or minimized. This prevents heat loss through weak points in the building’s structure;
Sun-oriented design: The arrangement of architectural elements and windows is carefully planned to maximize solar energy utilization. This can contribute to passive heating during the winter.

The crucial role of renewable energy in Passive Houses

Passive houses are a milestone in sustainable architecture, aiming to minimize energy consumption through intelligent design and efficiency. However, the building components of a passive house alone are not enough to fully meet the energy needs of the dwelling. Therefore, it is essential to integrate renewable energy sources from natural resources such as the sun, earth, water, and soil.
For this reason, when designing a passive house, the possibility of a roof with a photovoltaic system capable of harnessing solar energy to produce hot water for both sanitary and internal heating is typically considered. Alternatively, one can opt for a green roof to improve the building’s thermal and acoustic insulation. In the case of a passive house with a garden, geothermal energy can be harnessed through a ground-to-water heat pump system connected to probes in the ground. These probes capture heat from the ground and transfer it to radiant panels inside the house, ensuring efficient and sustainable heating. During the summer, the process is reversed, channeling the ground’s coolness from the panels to the probes, helping maintain a cool and comfortable indoor climate.

In conclusion, through the right combination of advanced design and renewable energy technologies, the design of passive houses can reduce environmental impact and offer a sustainable and incredibly comfortable living environment for their occupants.

Advantages of Passive Houses

A passive house represents the future of sustainable construction. Thanks to the adoption of innovative technologies and careful design, these houses demonstrate an approach to living that is both environmentally friendly and economically advantageous. The advantages offered by passive house design are numerous, including:

High energy efficiency: They dramatically reduce energy consumption for heating and cooling, leading to significant long-term cost savings;
Superior comfort: They ensure consistent thermal comfort and superior indoor air quality through controlled ventilation systems;
Reduction of CO2 Emissions: They contribute to reducing greenhouse gas emissions due to reduced dependence on traditional energy sources;
Environmental sustainability: They promote the conservation of natural resources and environmental sustainability through the use of eco-friendly materials and responsible construction practices.

What is a Digital Twin?

The concept of a digital twin (Digital Twin) has gained significant attention and practical application in various sectors, including construction, emerging as a fundamental technology in the contemporary digital era. But what exactly is a “digital twin”?

A digital twin is a virtual representation, a digital model that acts as a mirror of its physical counterpart, providing a dynamic and real-time view of an object, process, or system. This model is not static or limited to a simple visual replica; rather, it is powered and constantly updated by data from various sources, such as sensors, IoT devices, and monitoring platforms, creating a digital image that reflects and simulates the current state and operating conditions of the physical entity.

The implementation of a digital twin in the construction industry extends beyond the design or construction phase, covering the entire lifecycle of the physical object, from conception to demolition. The detailed and up-to-date information provided by the digital twin assists users in monitoring performance, predicting and identifying potential issues, and optimizing maintenance and management of the physical object. Furthermore, the digital twin is not an isolated entity but is capable of creating a digital bridge that connects data, processes, and people, facilitating a bidirectional flow of information and enabling dynamic interaction between the physical object and its digital model. The digital twin becomes a “single point of truth”, offering a reliable and consistent source of information on which to base informed decisions and operational strategies.

Digital Twin of a building: Data and Information

Creating and operating a Digital Twin

The creation of a digital twin begins with the construction of an accurate digital model of the physical object or system under examination. This goes beyond a mere visual replica, incorporating a range of data and information that enables the reflection and simulation of the behavior and conditions of the real entity in a virtual environment. The creation of the digital twin can make use of various technologies and methodologies, including terrestrial photogrammetry, which utilizes photographs and reference measurements to create accurate and detailed models, and the use of 3D models, often created through BIM modeling platforms in the context of construction.

The operation of the digital twin is closely tied to its ability to simulate, analyze, and predict the behavior of the physical object, providing users with a means to conduct experiments, test hypothetical scenarios, and make informed decisions without interfering with the real object. This is made possible through the use of advanced simulation engines and rendering technologies, allowing for realistic and detailed visualization and interaction with the virtual environment.

However, the creation and management of a digital twin require a deep understanding and integration of various technologies and disciplines, including IoT, artificial intelligence (AI), machine learning (ML), and data analysis, all converging to provide a digital model that not only replicates but also enhances the physical reality with insights and advanced functionalities.

Integration with Data and IoT

One fundamental feature of the digital twin is its ability to integrate data from a multitude of sources, creating a model that is not only representative but also dynamic and responsive to variations in the state of the physical object. Data can come from sensors, IoT devices, and other monitoring platforms, providing real-time information about the state, conditions, and performance of the physical object.
The Internet of Things (IoT) plays a crucial role in this context, providing the means to collect, transmit, and receive data between the DT and the physical object. Sensors and IoT devices installed on the physical object collect data on various parameters and transmit it to the digital twin, which then uses this information to update the model and reflect the current conditions of the real object. This continuous data integration allows the digital twin to function as a single point of truth, offering a consistent, accurate, and timely view of the object or system under examination.

Moreover, data integration in the digital twin goes beyond mere data collection and visualization. Data is analyzed, interpreted, and used to power simulations, predict trends, and identify potential issues or optimization areas. In this way, it promotes proactive, data-driven management of the physical object.

Virtual and Augmented Reality in the Digital Twin

Virtual Reality (VR) and Augmented Reality (AR) are technologies that enable users to immerse themselves and interact with virtual environments or overlay virtual elements onto the real world. In the context of the digital twin, VR and AR offer unique opportunities to visualize, explore, and interact with the digital model in intuitive and engaging ways:

Immersive Visualization: VR allows users to explore the digital twin’s virtual environment immersively, providing a deeper and more intuitive understanding of the structure and dynamics of the physical object;
Advanced Interaction: AR enables the overlay of the digital twin onto the real world, providing real-time information and data while interacting with the physical object, facilitating operations such as maintenance, inspection, and training;
Simulation and Experimentation: VR and AR allow the simulation of various scenarios and conditions in the digital twin, enabling users to test and experiment with strategies and solutions in a safe virtual environment before implementing them in the real world.

How the Digital Twin supports the design of a Passive House

The digital twin can be a revolutionary innovation in sustainable construction as it offers a comprehensive and detailed view of building performance. The future of designing efficient and highly comfortable passive houses undoubtedly lies in the use of this technology.

So, if you intend to capitalize on the growing demand for sustainable, environmentally-friendly solutions in response to the environmental crisis, I recommend starting to explore the use of digital twin software immediately and experiencing the advantages it offers through:

the creation of virtual environments;
realistic simulation and interaction;
data-driven decision-making.

Creation of Virtual Environments

The creation of virtual environments within the digital twin goes beyond simple 3D modeling of the physical object. It involves building a digital ecosystem that reflects not only the form and structure of the object but also its functionality, operational dynamics, and interactions with other objects or the surrounding environment.
Creating virtual environments within the digital twin plays a crucial role in the design of passive houses as it allows for highly detailed modeling. In fact, the virtual environment in the digital twin is modeled with a high degree of precision to ensure an accurate reflection of the physical object and its features. In these virtual environments, it is possible to experiment with the layout of indoor and outdoor spaces of the building. This includes optimizing room arrangements, windows, and partition walls to maximize natural lighting, improve airflow, and reduce the need for artificial lighting and excessive heating/cooling. Furthermore, it is possible to test various construction material options to evaluate their environmental impact and thermal insulation effectiveness.

Simulations and Realistic Interactions

The ability to conduct simulations and realistic interactions within the digital twin allows for experimenting, testing, and optimizing various scenarios, strategies, and solutions in a safe virtual environment before implementing them in the real world. The digital twin offers architects and engineers the ability to:

perform dynamic simulations: the digital twin enables the simulation of operational dynamics, workflows, and variable scenarios, providing insights into performance, efficiency, and any potential bottlenecks or issues in the physical object;
real-time interaction: users can interact with the digital twin in real-time, modifying various parameters, activating or deactivating functions, and observing the effects of their actions in the virtual environment;
conduct detailed analysis: simulations and interactions in the digital twin provide valuable data that can be analyzed to assess the effectiveness of various strategies, identify areas for improvement, and optimize operations and decisions.

In the realm of sustainable building design, these simulations prove to be a powerful tool for analyzing and experimenting with building performance in various scenarios and improving energy efficiency, sustainability, and occupant comfort.

Data-Driven Decision-Making

The digital twin not only provides a platform for data collection and analysis but also a means to facilitate data-driven decision-making. Insights and information derived from data analysis within the digital twin can be used to inform and guide decisions throughout the life cycle of the physical object, from design and construction to maintenance and optimization.
Data-driven decisions stemming from the digital twin are informed, timely, and targeted, enabling industry professionals to act proactively rather than reactively. This is of great relevance in sustainable building design as it allows for:

identify energy consumption needs: by collecting data on energy demand, including consumption peaks and usage patterns, it’s possible to better understand how the building will be used. This information helps in designing optimized heating, ventilation, and air conditioning (HVAC) systems, thereby reducing energy consumption and greenhouse gas emissions;
monitor and manage energy usage: data-driven monitoring systems allow real-time tracking of the building’s energy consumption. This data is essential for identifying waste and inefficiencies, enabling the timely correction of anomalies and the optimization of systems to maximize energy efficiency;
optimize lighting and environmental control: lighting data, including natural and artificial light levels in different parts of the building, helps design lighting systems that only turn on when and where they are needed, reducing excessive energy consumption. Additionally, data on humidity, temperature, and airflow can be used to automatically regulate the indoor environment, optimizing occupant comfort without energy wastage;
analyze the life cycle and building materials: data-driven analysis of the life cycle of materials allows for evaluating the environmental impact of each material used in construction. This aids in selecting sustainable materials and reducing the overall ecological footprint of the building;
gain continuous feedback for optimization: data collected after the building’s occupation provides valuable real-time feedback on performance. Usage metrics, occupant habits, and energy consumption data help optimize existing systems and inform decisions for future sustainable designs.

Examples of using the Digital Twin for Passive Houses

The digital twin offers a wide range of practical applications in the field of passive house design. Here are some of them:

ability to simulate and optimize building behavior in different scenarios. This includes a detailed analysis of energy performance, allowing designers to identify inefficiencies and make changes in the design process to maximize energy efficiency;
advanced management of heating, ventilation, and air conditioning (HVAC) systems, dynamically adjusting these functions to adapt to occupant needs and real-time climate variations;
creation of interactive simulation models that engage occupants in energy consumption management. These models enable users to visualize the impact of their actions on the building’s energy consumption, encouraging more sustainable practices;
analysis of historical and real-time energy usage data, operational efficiency, and preventive maintenance. Informed data analysis supports strategic decisions in the ongoing management of passive houses, ensuring that they are not only sustainable in the present but also in the long term.