6 social housing units on rental basis
Basic information
Project Title
6 social housing units on rental basis
Full project title
6 social housing units on rental basis, Santa Eugènia, Mallorca
Category
Shaping a circular industrial ecosystem and supporting life-cycle thinking
Project Description
'We do not live in a house but an ecosystem'
The project develops the research for a new model of production and consumption for global social justice and well-being started in Life Reusing Posidonia (2012-2020), a climate change adaptation project winner of the 2021 LIFE environment Award by the EU. One of the main improvements over the previous projects is standardisation to compensate the extra cost of local low carbon vernacular materials.
The project develops the research for a new model of production and consumption for global social justice and well-being started in Life Reusing Posidonia (2012-2020), a climate change adaptation project winner of the 2021 LIFE environment Award by the EU. One of the main improvements over the previous projects is standardisation to compensate the extra cost of local low carbon vernacular materials.
Geographical Scope
Local
Project Region
Santa Eugenia, Mallorca, Spain
Urban or rural issues
It addresses urban-rural linkages
Physical or other transformations
It refers to a physical transformation of the built environment (hard investment)
EU Programme or fund
Yes
Which funds
Other
Other Funds
Next Generation EU
Description of the project
Summary
6 social homes on rental basis for vulnerable people in Mallorca, designed by civil-servant architects of IBAVI, the public agency of the Regional Government responsible for providing and maintaining social housing.
There are three homes on the ground floor, and three homes on the first floor. The access to the dwellings is through the rear courtyard to provide a common space as green as possible to improve the sense of community. In addition, all the dwellings have a little private outdoor patio at the entry.
Santa Eugenia is a small picturesque town. IBAVI has been developing 46 social housing buildings around the four Balearic Islands, at the scale of every city and town. Here, this is one of the first buildings you see from distance when you arrive to Santa Eugenia, just below the town's main church, so landscape integration was essential to eradicate the stigma suffered by social housing. However, landscaping has not been solved from the form or shape, but from the use of local low carbon materials and the update of vernacular construction techniques as the most efficient way to use these resources.
This project develops the research for a new model of production and consumption for global social justice, well-being and integral sustainability started in Life Reusing Posidonia (2012-2020), a climate change adaptation project funded by the LIFE+ program from the EU (LIFE 2021 Environment Award). One of the main improvements over the previous projects is standardisation with natural materials, to make it more affordable.
The main priority was to ensure the comfort of the user and to prevent from energy poverty through passive bioclimatic solutions and locally sourced materials. The total heating and cooling energy demand is 4,80 kWh/m², which is 85% reduction compared to Passivhaus standard limits (15,00+15,00 kWh/m²).
Following a mapping of resources, 52% of CO2 embodied emissions were saved during construction, as well 50% of waste production
There are three homes on the ground floor, and three homes on the first floor. The access to the dwellings is through the rear courtyard to provide a common space as green as possible to improve the sense of community. In addition, all the dwellings have a little private outdoor patio at the entry.
Santa Eugenia is a small picturesque town. IBAVI has been developing 46 social housing buildings around the four Balearic Islands, at the scale of every city and town. Here, this is one of the first buildings you see from distance when you arrive to Santa Eugenia, just below the town's main church, so landscape integration was essential to eradicate the stigma suffered by social housing. However, landscaping has not been solved from the form or shape, but from the use of local low carbon materials and the update of vernacular construction techniques as the most efficient way to use these resources.
This project develops the research for a new model of production and consumption for global social justice, well-being and integral sustainability started in Life Reusing Posidonia (2012-2020), a climate change adaptation project funded by the LIFE+ program from the EU (LIFE 2021 Environment Award). One of the main improvements over the previous projects is standardisation with natural materials, to make it more affordable.
The main priority was to ensure the comfort of the user and to prevent from energy poverty through passive bioclimatic solutions and locally sourced materials. The total heating and cooling energy demand is 4,80 kWh/m², which is 85% reduction compared to Passivhaus standard limits (15,00+15,00 kWh/m²).
Following a mapping of resources, 52% of CO2 embodied emissions were saved during construction, as well 50% of waste production
Key objectives for sustainability
During its useful life, the building will produce emissions of 0,85 KgCO2 / m2 year, according to calculations. This constitutes an 80% reduction compared to the minimum threshold for consideration as energy class A. Aerothermal heat pumps are used to heat water, and most of the energy needed for this process comes from PV panels, but since we consider the hypothesis developed by A. Valero in ‘The mineral limits of the energy transition’, which provides the reasons to forecast an increase in prices and total shortages that will make inaccessible the minerals that are necessary for the production of all the renewable energies that are needed worldwide by the end of 2050, most of the energy efficiency comes from passive solutions. This is, from architecture itself:
_In summer, the passive strategies are inertia (mass) and hygrometric comfort provided by the stone, cross ventilation facing the prevailing breeze from the sea (Embat), sun protection through traditional wooden shades, and thick thermal insulation of 10 cm on walls and 24 cm on the roof. The active devices are fans on the ceiling with very low energy consumption.
_In winter, the passive strategies are very thick thermal insulation, highly insulated wood-framed windows with low-e double glazed glass filled with gas, and a large number of windows to collect as much sun as possible. The active device is a low-tech Trombe wall that faces south towards the neighbouring plot, which cannot be built on according to current Urban Development Regulations. During the cold months, the outside air is tempered by convection in the Trombe wall and distributed to the six homes by mechanical ventilation through individual pipes for each dwelling, consuming less than 50 W.
The building’s comfort will be monitored from winter 2023 to winter 2024 with the collaboration of the University of the Balearic Islands (UIB), to provide reference values for future regulations on the environmental impact of construction.
_In summer, the passive strategies are inertia (mass) and hygrometric comfort provided by the stone, cross ventilation facing the prevailing breeze from the sea (Embat), sun protection through traditional wooden shades, and thick thermal insulation of 10 cm on walls and 24 cm on the roof. The active devices are fans on the ceiling with very low energy consumption.
_In winter, the passive strategies are very thick thermal insulation, highly insulated wood-framed windows with low-e double glazed glass filled with gas, and a large number of windows to collect as much sun as possible. The active device is a low-tech Trombe wall that faces south towards the neighbouring plot, which cannot be built on according to current Urban Development Regulations. During the cold months, the outside air is tempered by convection in the Trombe wall and distributed to the six homes by mechanical ventilation through individual pipes for each dwelling, consuming less than 50 W.
The building’s comfort will be monitored from winter 2023 to winter 2024 with the collaboration of the University of the Balearic Islands (UIB), to provide reference values for future regulations on the environmental impact of construction.
Key objectives for aesthetics and quality
Since there are more than 7,000 spoken languages in the world, there might be, at least, the same number of languages of degrowth adapted to every place. This is just our example for Mallorca Island. With the motto “we do not live in a house but an ecosystem", the project links heritage, architecture, and climate change. It demonstrates that using vernacular architecture as guide map to find and source local materials enhances the connection to the place, to cultural heritage, and the efficiency of bioclimatic strategies. It is totally affordable, and the beauty of traditional architecture can be appreciated by everyone, no architectural knowledge is required.
Following a mapping of resources* in Mallorca, 52% of CO2 embodied emissions were saved during construction in comparison with an equivalent conventional building. Thanks to sustainable sourcing and urban mining of construction materials, like sandstone blocks, window blinds, and traditional Arabic tiles from the previous existing shack which has been totally reused, as well the recycled wooden formwork boards that support the 25 cm of Posidonia oceanica sea grass that act as insulation, the wood for all the interior doors, 50% of waste production was also avoided during the construction phase.
The local sandstone is low-carbon and provides mass and endurance to extend the useful life of the building, and is 100% recyclable. The three homes on the ground floor are organised in two parallel 3.5 metre stone barrel vaults supported on three axes of pilasters, also made of stone, which provides a very flexible layout that can be changed very easily through time. The rooms can be marked out using movable wooden doors that are the size of walls.
*Map of resources is the comprehensive study of site conditions: reusable resources and local surplus, available low carbon industries, building traditional techniques and vernacular typologies, crafts, available clean energies, full-cycle water management, etc.
Following a mapping of resources* in Mallorca, 52% of CO2 embodied emissions were saved during construction in comparison with an equivalent conventional building. Thanks to sustainable sourcing and urban mining of construction materials, like sandstone blocks, window blinds, and traditional Arabic tiles from the previous existing shack which has been totally reused, as well the recycled wooden formwork boards that support the 25 cm of Posidonia oceanica sea grass that act as insulation, the wood for all the interior doors, 50% of waste production was also avoided during the construction phase.
The local sandstone is low-carbon and provides mass and endurance to extend the useful life of the building, and is 100% recyclable. The three homes on the ground floor are organised in two parallel 3.5 metre stone barrel vaults supported on three axes of pilasters, also made of stone, which provides a very flexible layout that can be changed very easily through time. The rooms can be marked out using movable wooden doors that are the size of walls.
*Map of resources is the comprehensive study of site conditions: reusable resources and local surplus, available low carbon industries, building traditional techniques and vernacular typologies, crafts, available clean energies, full-cycle water management, etc.
Key objectives for inclusion
Public Social Housing in Balearic Islands includes protection of fragile categories, such as elderly people, disabled people, single-parent families (father or mother), and other vulnerable people. 10% of dwellings are reserved to young people.
The IBAVI dwellings rental cost average is €420 per month (5'15€/m2). The average monthly rental price for houses currently on the private market in Santa Eugenia is €2,500, because the rental cost is 13'75€/m2 and there are not available small flats.
The base rent is €7.57/m2, but is adapted to the income of each cohabitation unit, and it finally ranges between €2.54/m2 and €6.20/m2, so the tenants never pay more than 30% of their salary.
The IBAVI dwellings rental cost average is €420 per month (5'15€/m2). The average monthly rental price for houses currently on the private market in Santa Eugenia is €2,500, because the rental cost is 13'75€/m2 and there are not available small flats.
The base rent is €7.57/m2, but is adapted to the income of each cohabitation unit, and it finally ranges between €2.54/m2 and €6.20/m2, so the tenants never pay more than 30% of their salary.
Results in relation to category
DIRECT BENEFITS:
1/ - 52 % embodied CO2 emissions: 304.67 kg/CO2 x m².
Embodied carbon emissions during the execution of the works, compared to an equivalent building simulating conventional construction systems with 635.92kg/CO2 x m². CYPE calculation program.
2/ - 86.20 % energy demand for cooling and heating: 4.80 kWh/m².
Percentage of reduction compared to an average value of cooling and heating annual demand with 34.73 kW/h x m².
3/ - 50 % waste production during the works: 20.11 tn.
Percentage of waste reduction based on the calculation of theoretical production.
4/ - 26.70 % water consumption during useful life: 88 liters per person and day.
Percentage of reduction compared to a reference apartment building with no garden and an average consumption of 120 liters·person·day.
5/ Six vulnerable families from a very small town (1.700 inhabitants) had acces for a decent affordable housing, with an average rental cost of €420 per month (€5'15/m² average, between €2.54/m² and €6.20/m²), so the tenants never pay more than 30% of their salary.
INDIRECT BENEFITS / Cultural heritage
Thanks to IBAVI projects and other architects in the island to make feasible the construction with sandstone, local quarries are not anymore in danger of extinction because of people retirement age. Investments to update the facilities have been made and new young workers have been hired.
IMPACTS / Change of model
A/ The project was selected to be featured in the Living Spaces catalogue on high-quality architecture and built environment, promoted by Eurocities.
B/ In 2022 it received the international Architectural Review Emerging Award for young architects up to 45 years old from all over the world.
C/ In 2023 it has been published on the cover of El Croquis 219.
The Cervantes Institute and the RIBA Institute have described the magazine El Croquis as one of the most relevant and prestigious architecture publications in the international arena.
1/ - 52 % embodied CO2 emissions: 304.67 kg/CO2 x m².
Embodied carbon emissions during the execution of the works, compared to an equivalent building simulating conventional construction systems with 635.92kg/CO2 x m². CYPE calculation program.
2/ - 86.20 % energy demand for cooling and heating: 4.80 kWh/m².
Percentage of reduction compared to an average value of cooling and heating annual demand with 34.73 kW/h x m².
3/ - 50 % waste production during the works: 20.11 tn.
Percentage of waste reduction based on the calculation of theoretical production.
4/ - 26.70 % water consumption during useful life: 88 liters per person and day.
Percentage of reduction compared to a reference apartment building with no garden and an average consumption of 120 liters·person·day.
5/ Six vulnerable families from a very small town (1.700 inhabitants) had acces for a decent affordable housing, with an average rental cost of €420 per month (€5'15/m² average, between €2.54/m² and €6.20/m²), so the tenants never pay more than 30% of their salary.
INDIRECT BENEFITS / Cultural heritage
Thanks to IBAVI projects and other architects in the island to make feasible the construction with sandstone, local quarries are not anymore in danger of extinction because of people retirement age. Investments to update the facilities have been made and new young workers have been hired.
IMPACTS / Change of model
A/ The project was selected to be featured in the Living Spaces catalogue on high-quality architecture and built environment, promoted by Eurocities.
B/ In 2022 it received the international Architectural Review Emerging Award for young architects up to 45 years old from all over the world.
C/ In 2023 it has been published on the cover of El Croquis 219.
The Cervantes Institute and the RIBA Institute have described the magazine El Croquis as one of the most relevant and prestigious architecture publications in the international arena.
How Citizens benefit
Citizens have a new model of production and consumption that provides social justice, well-being and global sustainability. It is adapted to climate change and reduces both the collateral effects during the execution of the works (extraction of raw materials, labour exploitation, pollution, etc.) and during the useful life of the building, minimizing energy poverty and guaranteeing greater comfort in the face of extreme heat waves without requiring external energy.
In relation to the social housing tenants, sometimes they are also stigmatized by society and some people thought they were not going to appreciate the quality of the dwellings. Instead, they love it, and they were astonished: ‘I’ve would never dream to live in a house like this’.
They could not believe that they were going to live in highly efficient homes built with natural stone from Majorca, and paying an affordable rent.
So, we have verified that there has been a happy coincidence between both groups of stakeholders: tenants and architecture critic. This approach to climate change from vernacular looks for what is common to us collectively, such as the landscape that constitutes the set of anonymous traditional architectures. In this way, traditional architecture can be understood as a kind of universal beauty, where everyone can feel represented.
In relation to the social housing tenants, sometimes they are also stigmatized by society and some people thought they were not going to appreciate the quality of the dwellings. Instead, they love it, and they were astonished: ‘I’ve would never dream to live in a house like this’.
They could not believe that they were going to live in highly efficient homes built with natural stone from Majorca, and paying an affordable rent.
So, we have verified that there has been a happy coincidence between both groups of stakeholders: tenants and architecture critic. This approach to climate change from vernacular looks for what is common to us collectively, such as the landscape that constitutes the set of anonymous traditional architectures. In this way, traditional architecture can be understood as a kind of universal beauty, where everyone can feel represented.
Physical or other transformations
It refers to a physical transformation of the built environment (hard investment)
Innovative character
The main innovative character is to face sustainability from the specific conditions and low carbon resources of every specific region, away from the globalization of constructive solutions and the aesthetical prejudices from the Modern Movement, which is the expression of the materials produced with fossil fuel energies.
In this case, it demonstrates the viability and the value of incorporating local stone walls and barrel vaults in housing projects as the main strategy to provide thermal inertia to cool for free during the summer heat waves, through a low carbon structure as heavy as possible.
The 52% reduction of embodied CO2 emissions during the execution of works compared to a regular statistic building that complies with the current regulations, is achieved through a proper selection of materials, preferably local, recovering, insofar as possible, vernacular architecture techniques.
For instance, besides of the natural sandstone, which requires a very little amount of energy for its extraction at the quarry, it has been used recycled old wood for ceilings and indoor carpentries, and dry Posidonia Oceanica (Neptune grass) for thermal insulation λ=0,044W/mK, which makes visible the change of model:
“Instead of investing in a chemical plant located 1.500km away, we invest the same budget to local unskilled labour, which should extend the Neptune grass to dry under the sun and compact it in pallets, achieving 15cm of insulation in roof. Moreover, it turns out that sea salt acts as natural biocide product and is
completely environmentally friendly.”
This approach links environmental issues with the cultural heritage and tradition of each region, not only achieving an improvement in air quality and the prevention of global warming but also recovering the cities landscape quality and regaining a sense of belonging.
In this case, it demonstrates the viability and the value of incorporating local stone walls and barrel vaults in housing projects as the main strategy to provide thermal inertia to cool for free during the summer heat waves, through a low carbon structure as heavy as possible.
The 52% reduction of embodied CO2 emissions during the execution of works compared to a regular statistic building that complies with the current regulations, is achieved through a proper selection of materials, preferably local, recovering, insofar as possible, vernacular architecture techniques.
For instance, besides of the natural sandstone, which requires a very little amount of energy for its extraction at the quarry, it has been used recycled old wood for ceilings and indoor carpentries, and dry Posidonia Oceanica (Neptune grass) for thermal insulation λ=0,044W/mK, which makes visible the change of model:
“Instead of investing in a chemical plant located 1.500km away, we invest the same budget to local unskilled labour, which should extend the Neptune grass to dry under the sun and compact it in pallets, achieving 15cm of insulation in roof. Moreover, it turns out that sea salt acts as natural biocide product and is
completely environmentally friendly.”
This approach links environmental issues with the cultural heritage and tradition of each region, not only achieving an improvement in air quality and the prevention of global warming but also recovering the cities landscape quality and regaining a sense of belonging.
Disciplines/knowledge reflected
Architects, ecologist, structural engineer with heritage knowledge, environmental consultant, facilities engineer, 3D render designer, construction manager, economist and building contractor with knowledge of vernacular techniques.
Architects have coordinated the different teams through constant meetings throughout the entire process, with the goal to improve the previous designs since Life Reusing Posidonia.
Architects have coordinated the different teams through constant meetings throughout the entire process, with the goal to improve the previous designs since Life Reusing Posidonia.
Methodology used
The methodology is based on the 'map of local resources', which among other factors, such as social or atmospheric, includes low environmental impact materials, preferably local. In fact, the Balearic Islands Climate Change Law precisely states that 'Public Administrations will incorporate the use of low environmental impact construction materials, preferably of local origin'. Therefore, we have at our disposal both the materials of the industries that are making their ecological transition, as well as those of vernacular architecture, which have as value added that they are part of the cultural heritage and landscape of each place.
For example, the use of local stone as a loadbering structure. We've solved the structure with the same massive material to provide inertia, both vertically and horizontally, that requires a structure designed in compression, which basically means arches and vaults. One of the most revealing facts is that during the design process with the structural engineers we discovered that the barrel vault makes a lot of sense on the ground floor ceiling, but not on the first floor, because the horizontal thrusts are too high, and it is better to go for a slight pitched roof. And curiously, this is the usual typology in traditional Majorcan architecture.
That is to say, that by projecting without aesthetic prejudices of wanting to reach a certain final result that we have imposed on ourselves, we arrived at the same structural solution that had been developed over centuries of refinement.
So, it is always a matter of structural optimization of the materials which are part of your resource map to comply with decarbonisation objectives.
But it is important to remember that these materials are more fragile than conventional ones, and therefore in the design phase we must rethink the language we use to optimize the mechanical properties of the materials and their cost, without forcing them.
For example, the use of local stone as a loadbering structure. We've solved the structure with the same massive material to provide inertia, both vertically and horizontally, that requires a structure designed in compression, which basically means arches and vaults. One of the most revealing facts is that during the design process with the structural engineers we discovered that the barrel vault makes a lot of sense on the ground floor ceiling, but not on the first floor, because the horizontal thrusts are too high, and it is better to go for a slight pitched roof. And curiously, this is the usual typology in traditional Majorcan architecture.
That is to say, that by projecting without aesthetic prejudices of wanting to reach a certain final result that we have imposed on ourselves, we arrived at the same structural solution that had been developed over centuries of refinement.
So, it is always a matter of structural optimization of the materials which are part of your resource map to comply with decarbonisation objectives.
But it is important to remember that these materials are more fragile than conventional ones, and therefore in the design phase we must rethink the language we use to optimize the mechanical properties of the materials and their cost, without forcing them.
How stakeholders are engaged
Since Life Reusing Posidonia end of the works (2017), IBAVI is monitoring with the Balearic University the different promoted buildings and getting the feedback from the tenants, contractors and design teams in order to develop an ongoing improvement step by step. We use the data from every design to improve the next one. We've built 24 projects since Life Reusing Posidonia, and we still have 22 more under construction.
Global challenges
1. The global population growth forecast, according to the United Nations, is 1,700 million by 2050. In November 2022, the population reached 8,000 million, and in 27 years it is expected to reach 9,700 million.
2. We consider A. Valero's hypothesis (‘The mineral limits of the energy transition’) that in the coming years, from now on until 2050 (the deadline for zero emissions) there may be a lack of minerals for the production of the renewable energies we need globally, so it is essential to lower consumption, especially when population is growing up.
The aim must be to guarantee people's comfort by reducing as much as possible the energy demand for cold and heat through passive systems, from the architecture itself. Once we have agreed on this collective milestone, there can be many ways to respond, probably each one adapted to the map of resources of every place. The most efficient solutions are the ones that update the vernacular architecture. Like an igloo in the arctic, or a massive earth wall in a dessert.
3. Only at the end, to offset the remaining emissions through the generation of renewable energy, so that everyone can have access to clean energy globally.
2. We consider A. Valero's hypothesis (‘The mineral limits of the energy transition’) that in the coming years, from now on until 2050 (the deadline for zero emissions) there may be a lack of minerals for the production of the renewable energies we need globally, so it is essential to lower consumption, especially when population is growing up.
The aim must be to guarantee people's comfort by reducing as much as possible the energy demand for cold and heat through passive systems, from the architecture itself. Once we have agreed on this collective milestone, there can be many ways to respond, probably each one adapted to the map of resources of every place. The most efficient solutions are the ones that update the vernacular architecture. Like an igloo in the arctic, or a massive earth wall in a dessert.
3. Only at the end, to offset the remaining emissions through the generation of renewable energy, so that everyone can have access to clean energy globally.
Learning transferred to other parties
The main tool we provide which can be transferred to all the peripheral regions of Europe, and even to some parts of the main cities, is a different approach to sustainability towards degrowth.
This is, to be open to new architectonical languages which are coming from the local heritage to reduce the consumption of resources and achieve higher self-sufficiency.
In relation to the specific constructive solutions, they only should be transferred to other areas sharing similar resources maps, because every project should be the result of their own local low-carbon footprint resources. For instance, in this case, other places with sandstone quarries, like Cyprus, Sicily, other Italian and Greek Mediterranean islands, or Fontvieille, near Arles, in the French Provence, where Fernand Pouillon extract the sandstone to build thousands of dwellings during the sixties.
The documentation of the project is open source and freely available on the web https://contrataciondelestado.es
Furthermore, the 6 social housing units building is not an isolated project. It is part of a wider strategy to recover the use of local sandstone and to avoid the extinction of this low carbon industry in the Island of Majorca, which can be applied to other European areas.
This is, to be open to new architectonical languages which are coming from the local heritage to reduce the consumption of resources and achieve higher self-sufficiency.
In relation to the specific constructive solutions, they only should be transferred to other areas sharing similar resources maps, because every project should be the result of their own local low-carbon footprint resources. For instance, in this case, other places with sandstone quarries, like Cyprus, Sicily, other Italian and Greek Mediterranean islands, or Fontvieille, near Arles, in the French Provence, where Fernand Pouillon extract the sandstone to build thousands of dwellings during the sixties.
The documentation of the project is open source and freely available on the web https://contrataciondelestado.es
Furthermore, the 6 social housing units building is not an isolated project. It is part of a wider strategy to recover the use of local sandstone and to avoid the extinction of this low carbon industry in the Island of Majorca, which can be applied to other European areas.
Keywords
new model
heritage
ecosystem
climate change adaptation
resources map
