How is it possible to reduce the energy consumption of our homes? What design, material, and/or technological strategies can be developed to achieve interior comfort while also addressing the climate crisis? While achieving energy efficiency depends, among other factors, on the state of the homes, there are various strategies related to the implementation of renewable energies, air conditioning technologies, and more that can be applied, taking into account government policies, laws, regulations, and standards specific to each region.
According to the Institute for Energy Diversification and Saving (IDAE) of Spain, 20% of homes have effective insulation capable of preventing heat loss in winter and the entry of hot air in summer through walls, doors, and windows, thereby reducing energy consumption. While countries like Argentina and Chile are just starting to move toward energy efficiency labeling, in Spain, according to the IDAE report from December 2021, only 0.3% of homes have an A certification, representing the highest efficiency, with G certification being the minimum.
Just as there is ongoing debate in Latin America regarding energy efficiency and decarbonization of buildings, in Europe, for instance, there is an increasing expectation to replace natural gas with solar energy for electricity and heat generation. There is a push to make the most of rooftops, intending to make photovoltaic panels mandatory on most public buildings, homes, and residential blocks between 2027 and 2029. According to the Spanish Photovoltaic Union (UNEF), in 2021, twice as many solar panels were installed compared to 2020, and there is an aspiration for this trend to continue growing.
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Cooling and Energy Efficiency: A New Era in Building Design
Facing a significant journey ahead in terms of sustainable construction practices on both continents, energy-efficient architecture can be implemented through considerations such as project orientations and ventilations, degrees of thermal insulation based on materials or construction technologies, self-sufficient energy consumption systems, and the reuse of rainwater. These efforts contribute to the reduction of CO2 emissions into the atmosphere and the overall pollution levels on the planet. Below, we highlight 10 homes in Spain that apply various passive strategies and bioclimatic designs, aiming to achieve maximum energy efficiency.
Passive and Bioclimatic Single-Family Homes in Santiago de la Ribera / Ecoproyecta
- Location: San Javier, Spain
- Year: 2022
"The House of Corners: Designing Passive and Bioclimatic Architecture - This project celebrates sustainability and energy efficiency in a versatile home with multiple spaces for various uses. Designed for a couple with a child, this dwelling faces the challenge of a north-facing orientation on its longer side and a facade that opens to the west. The goal is to create a comfortable, healthy, and low-energy living space, making the most of every detail both indoors and outdoors."
[...] "Bioclimatic Strategies for Energy Efficiency - The primary goal is to maintain a comfortable indoor environment with low energy consumption. We've implemented bioclimatic strategies that enable the house to function passively for most of the year. The main approach has been the overall organization of the house, considering orientation and the outdoors, as previously explained. But there are other strategies: Green roofs that not only reintroduce green areas but also act as thermal insulation. The "earthenware pitcher effect" for cooling in the summer, using drip irrigation on the rooftop. Wooden carpentry and efficient glass. Sun protection through Mallorcan-style shutters. Skylights to increase natural light."
Learn more about this project here.
Countryside House Zafra de Záncara / Canobardin
- Location: Zafra de Záncara, Spain
- Year: 2022
[...] "The water needed for the house is obtained from a nearby well and due to the absence of an electricity supply, the water pumping is carried out by a magnificent solar photovoltaic installation which also supplies the house with electricity."
"This means, the owners can enjoy how the seasons pass by and contemplate how the crops change throughout the year in a 100% self-sufficient manner and without depending on any external supply. The heating of the house is provided by a biomass boiler which, together with the good insulation of the house, means that in just a few hours the house is warmed up and ready to be lived in, even on the coldest days of the cold winters in Cuenca."
Learn more about this project here.
Two Houses at Vidrà / Sau Taller d'Arquitectura
- Location: Vidrà, Spain
- Year: 2022
[...] "The main objectives of the project are, on the one hand, to achieve low environmental impact and high energy efficiency, and on the other, to offer a high-quality product at a competitive cost and finally, proposing an architecture integrated into the landscape."
"To solve this triple objective, the proposal is to:
Work with bare, neutral materials with the idea of making the most of the characteristics of each material and reducing the environmental impact in the construction process. Thus, a large concrete plinth is projected to resolve the unevenness of the plot. The entire project is developed with dry construction based on a laminated wood structure, interior finishes of three-layer fir panels, insulation of wood fibers, and a ventilated façade with a wood-cement composite panel. In addition, a commitment is made to minimizing the openings and placing the essential ones strategically to achieve good solar radiation. In this way, the building behaves fabulously well since there are almost no thermal bridges, reducing consumption to a minimum throughout their useful life."
Learn more about this project here.
Puigpunyent Eco-Passive House / Miquel Lacomba Architects
- Location: Puigpunyent, Spain
- Year: 2021
"The house uses the main passive resources such as south-facing orientation, sunlight control, high thermal insulation thickness, control of thermal bridges, good air tightness to outside air, double flow of mechanical ventilation with heat recovery, and high insulation and airtight windows. The solar panels cover the energy demand for the rest of the house. Although it is a passive house, cross ventilation has been taken into account, since on summer nights the natural coolness of the valley is used to cool the house naturally."
"The house was built with ecological and sustainable materials, horizontal wood structure from sustainably managed forests, ceramic brick, hydraulic lime mortar, natural cork insulation, and lime-based acrylic finishes on the facade. For the interior finishes, natural oil-based wood products, silicate paints, and stone treatments with A+ and “Ecolabel” seals have been used, i.e. almost “0” VOC emission in the interior, ecological and environmentally friendly. In this way, the building envelope of the house has been conceived as a “third skin”, all the materials of which it is composed allow breathability to water vapor and are free of VOCs. It should be added that materials such as lime, being hygroscopic, allow humidity to be regulated naturally. To minimize the ecological footprint, the “kilometer “0” concept has been incorporated by working with builders and industrialists close to the construction area and, where possible, using local or national materials. All these applications and criteria have contributed to ensuring that the house’s energy consumption is very low, whilst at the same time providing a very high level of comfort as well as contributing to a respectful commitment to the environment."
Learn more about this project here.
ShowPass Refurbishment / Energiehaus Arquitectos
- Location: Barcelona, Spain
- Year: 2021
"ShowPass proposes energy efficiency actions with a broader focus to demonstrate and disseminate the viability of EnerPHit energy retrofit in the Mediterranean as a reference standard. Moreover, ShowPass proposes a certified carbon-neutral building to mitigate the effects of climate change, while guaranteeing its dwellers a very high level of comfort and health."
[...] "A wide variety of low-impact ecological material solutions have been used to demonstrate and disseminate the feasibility of technologies in line with the need to decarbonize our buildings. For the street façade, thermal insulation with calcium silicate has been chosen on the inside to respect the original façade and to deal with the humidity by capillarity of the subsoil. On the other hand, fire-retardant glass wool insulation has been used in the ventilated façade of the patio, complemented with recycled cotton insulation inside. The annex in the patio is insulated with wood-fiber boards and clay mortar for optimal passive moisture management in summer. On the ground floor, a floating floor is installed on 10 cm thick high-density rock wool plates. To acoustically and thermally seal the building's construction joints, sheep wool from a local manufacturer and certified low-emission sealing tapes have been used. In addition, an energy recovery system of shower water has been installed to reduce the energy consumption of DHW (domestic hot water), one of the principal sources of CO2 gas emissions in a Passive House."
"Regarding the active HVAC system, an air-to-water heat pump with a solar evaporator has been installed, thus eliminating the electrical consumption of the fan in the external device, as well as a compact heat exchanger with an integrated recirculation and heating/cooling device. According to the calculations of the PHPP (Passive House Planning Package) tool, the ShowPass building saves about 80% of its greenhouse gas emissions in the operational phase. Likewise, users enjoy almost zero energy consumption with high comfort in the city center."
Learn more about this project here.
Rambla Climate-House / Andrés Jaque / Office for Political Innovation
- Location: Molina de Segura, Spain
- Year: 2021
"The Rambla Climate-House works as a climatic and ecological device. It is part of a series of associative initiatives, developed at the scale of independent citizens, to contribute to reparations for the environmental and climate damage caused by over-urbanization in Molina de Segura." [...]
"Thermally, the construction of the house tests unorthodox ways to maximize energy efficiency. A marble bench around the elliptical section allows residents to cool off by allowing direct contact to the house’s thermal inertia. A coil exposed to the sun, crowning the elliptic section, provides passive hot water during the entire year."
Learn more about this project here.
Passive House in Arteaga / Lopez Rivera
- Location: Guategiz Arteaga, Spain
- Year: 2021
"Passivhaus standards have been followed in the design and construction of the house, insulating the four ventilated sides of the exterior envelope extensively. Very hermetic enclosures have been used with triple Low-E glass and a total absence of thermal bridges and air leaks. External solar protections made of horizontal roll-up slats of Soria pine have been incorporated in the areas with the most intense solar exposure in the summer. The extraction and supply of air from the house is constant and controlled using a double-flow mechanical ventilation system that incorporates a heat recuperator to transfer part of the energy contained in the stale extraction air to the fresh air that is introduced into the house. With the sum of these measures, a 75% reduction in heating and cooling consumption is achieved compared to a standard home."
"The house obtained the class A energy rating with an energy consumption of 22.43 kWh/m2 per year and emissions of 3.83 kg of CO2/m2 per year. The power contract with the electricity company is 4.6 Kw."
Learn more about this project here.
The Day After House / Takk
- Location: Madrid, Spain
- Year: 2021
"The Day After House is the renovation of a 110 sqm apartment in Madrid with the aim of updating the domestic space according to the new models of use and environmental consciousness after the emergence of the new climate regime and fossil fuel crisis."
[...] "The first one is the work with thermal gradients for the functional and programmatic configuration of the house, as opposed to a more traditional scheme based on the combination of rooms and corridors. In the new proposal, the distribution considers the climatic and environmental specificities of each space. As if it were the layers of an onion, the spaces of the house get nested each one inside of another. This operation allows us not to use corridors saving this space for the rest of the house as well as working as a method for saving energy. As we get close to the central spaces of the house, they get more and more insulated and have fewer needs in terms of extra energy. This kind of climatic diverse distribution is inserted in a context of energetic scarcity and a continental climate characteristic from Madrid, with strong heat waves during summer and intense cold periods in the winter, and allows us to unify functional program, climate, and efficiency."
Learn more about this project here.
Casa ecológica Sant Feliu 369 / Pia Capdevila
- Location: Sant Feliu de Llobregat, Spain
- Year: 2021
"The energy consumption of this 120m2 single-family home with two bedrooms and two bathrooms, located in the town of Sant Feliu de Llobregat (10km from Barcelona), is zero as it self-regulates its temperature and is constructed with non-toxic materials. Its south-facing orientation further helps reduce energy consumption. All of this is made possible through bioarchitecture and bio interior design, two disciplines that bring sustainability to construction and interior design, creating healthy spaces for both inhabitants and the environment."
[...] "Furthermore, the residence follows the Passivhaus construction type or passive house, which maximizes the use of sunlight to require minimal energy for indoor living. This is achieved through large openings in the facade wall, which receives ample sunlight throughout the year, and three double-glazed windows with low-emissivity glass filled with argon gas. On the exterior, the facade is enveloped by a layer of cork insulation approximately 10cm thick. Alongside the joinery of chestnut wood from Montseny, this ensures the overall airtightness of the entire house."
Learn more about this project here.
Casa Woodcase / Ayllón Paradela Deandrés arquitectos
- Location: Madrid, Spain
- Year: 2021
"Comfort and energy efficiency. On an energy level, the massive nature of the complex is the strategy for comfort. A thick envelope of thermo-clay walls and solid concrete slabs ensure high thermal inertia, treating the house itself as a great thermal accumulator. The generous openings allow for sunlight capture in winter, minimizing heating demand. In summer, exterior blinds provide protection, reducing the need for cooling."
"The deciduous vegetation and landscaped surroundings to the south, along with the water feature to the west, create a small microclimate around the home, benefiting all interiors through natural ventilation. For peak demand periods, there is a radiant-cooling floor with aerothermal production as a renewable energy source, combined with an enthalpy heat recovery system. A system of photovoltaic solar panels capable of producing 4.5 kW of energy for self-consumption complements the overall setup."
Learn more about this project here.
* The texts are descriptions sent by the authors of the projects themselves.
