At Aiguasol, we conducted a study to evaluate the bioclimatic performance of the Centre Cívic de Cunit, commissioned by ROA Arquitectura. With the goal of creating a Nearly Zero Energy Building (NZEB), our work focused on minimizing energy demand and exploring strategies to achieve a low-consumption building or even one that is energy-neutral or positive.

High-standard construction according to european regulations

The construction sector is responsible for 40% of energy consumption and 36% of CO₂ emissions in the EU. The Energy Performance of Buildings Directive (EPBD) was created to meet the European Union’s energy and environmental targets. Still in the proposal phase, this directive states that new buildings must be zero-emission, with primary energy consumption below 60 kWh/m² per year in Mediterranean and oceanic climates. Additionally, energy consumption must be covered by on-site renewable sources, a renewable energy community, or an efficient urban heating/cooling system.

The study conducted by Aiguasol at the Centre Cívic de Cunit was carried out within this regulatory framework to meet sustainability standards. The work follows the guidelines established by the EPBD 2022, ensuring the building complies with energy and environmental requirements, promoting decarbonization and energy efficiency.

Aiguasol’s Expertise in the Project

Within the framework of the project, Aiguasol has carried out a thorough and detailed analysis of various key aspects to ensure an efficient and sustainable building design. Our experience in building design allows us to provide a comprehensive and rigorous approach, combining advanced simulation tools with environmental and energy criteria to optimize the building’s performance in all its dimensions. The tasks carried out in the project include:

Study of the building’s passive behavior

Using dynamic multizone simulation tools such as Design Builder, we have modeled the building’s thermal behavior to analyze its energy demands, required power, and indoor thermal comfort. This process has allowed us to precisely understand how different climatic and architectural variables interact in the building’s energy consumption. Based on this analysis, we have established a robust reference model that has helped us refine and optimize passive strategies for reducing energy demand, thus ensuring greater overall efficiency.

Study of natural lighting

Harnessing natural light is essential in any sustainable building, as it not only reduces electricity consumption but also improves users’ well-being and productivity. For this reason, we have conducted a detailed study of the building’s natural lighting, assessing its efficiency and ensuring that different workspaces receive an optimal level of daylight. This analysis was based on the criteria established by the VERDE Certification and considered three fundamental aspects: daylight factor (DF), spatial daylight autonomy (sDA), and glare risk. Through this study, we have developed strategies to balance visual comfort and energy efficiency.

Study of a Canadian well system for pre-treating incoming air

To optimize the building’s climate control, we have assessed the feasibility of using Canadian wells, a system that leverages heat exchange with the ground to pre-treat incoming air. Using the dynamic simulation tool TRNSYS, we have modeled the effect of this thermal exchange between the ground and the air, determining its effectiveness in terms of energy savings and analyzing its investment cost. Our methodology allows us to accurately evaluate the profitability of this technology, adapting sustainability strategies to the specific conditions of the building and optimizing decision-making from both a technical and economic perspective.

Feasibility study of energy systems

The choice of the thermal generation system is one of the key elements in achieving an efficient and sustainable building. In this regard, we have analyzed different thermal generation scenarios, combining aerothermal and geothermal systems and evaluating them from a life cycle perspective. This analysis goes beyond the classic comparison of initial investment and economic savings, incorporating environmental and energy criteria to determine the optimal strategy. Through a multiparametric analysis, we have identified the most efficient combination of technologies in terms of sustainability, maximizing energy efficiency and minimizing environmental impact.

Study of emissions balance

To evaluate the building’s capacity for self-generating and self-consuming renewable energy, we have conducted an hourly analysis of the emissions balance. This study has allowed us to quantify the renewable fraction of the energy consumed and determine the proportion of energy produced on-site through photovoltaic panels installed on the roof. To achieve this, we analyzed the electrical consumption of climate control, lighting, ventilation, domestic hot water, and equipment, comparing them hour by hour with photovoltaic generation. This has enabled us to precisely size the self-consumption system’s capacity and optimize its integration into the building’s energy strategy.

Our goal? To create a building capable of reversing the energy cycle: minimizing needs, implementing cutting-edge energy systems, and prioritizing on-site renewable energy generation.

The study conducted at the Centre Cívic de Cunit is an example of how technology and bioclimatic design can come together to create more efficient, comfortable, and environmentally friendly spaces. We will continue working to promote more responsible construction aligned with future environmental challenges.