Mallorca finds the solution

As Mallorca’s third largest city, Inca is able to breathe a sigh of relief. Tenants at Canonge Sebastia Garcias Palou nº 49 have moved into their new homes at last. The project known as 54 HPP Inca will take at least some of the pressure off the city’s housing situation. Although Inca’s location away from the sea makes it less attractive to tourists and those with second homes, a growing number of locals are moving to the city because housing has become unaffordable on the coast. And so here, too, rent has increased and people looking for a roof over their heads have been growing desperate.

For years, affordable rent has been one of the biggest social issues on the island. Especially as the state only provides funding for a very small percentage of all homes – no more than 0.6 percent. Social housing is expected to relieve the housing shortage. Founded back in 1986 as a public institution of the regional transport and building ministry, the Instituto Balear de la Vivienda (IBAVI) is the main player here, and it is also the building contractor.

Not much has happened over the past four decades, however. Mallorca is not such a large place, and its population is only slightly more than one million people. That said, the 1,800 existing council flats are no more than a drop in a very large ocean. And so 900 more homes are being built to stem the increasing social floodwaters.

Hasty, but not harmful

And even though a hasty solution was needed, it wasn’t going to be at the expense of the environment. Instead, these homes were constructed in line with the principles of the EU-funded programme Life Reusing Posidonia. The focus here is on a construction method that protects the climate and uses regional building materials with a low carbon footprint – including wood, of course, but also seagrass, limestone and clay bricks.

But there’s more: the planned constructions look good as well. They are truly a world apart from the cliches associated with dreary, grey social housing. On the contrary: most of these new buildings have been designed by independent architectural studios. Contractor IBAVI has involved leading players in Spanish architecture – such as Peris + Toral, HArquitectes and López Rivera. These are joined by an increasing number of young, ambitious and highly motivated planners who have specialized in bioclimatic projects.

New generation of ideas

This is exactly what happened in the aforementioned small town of Inca. The young professionals at Barcelona-based Alventosa Morell Arquitectes worked with the architects at Joan Josep Fortuny Giró to design the publicly funded social housing project 54 HPP Inca. They operated under the name of Fortuny – Alventosa Morell with aim of “designing socially, economically and ecologically responsible buildings that are attractive and innovative”. The finished constructions now offer 54 flats with total floor space of 4,633.60 square metres, plus 1,746.90 square metres in the underground car park.

Their design joins up existing buildings, creating a complete block. The flats are situated in two perpendicular three-storey units, with one central staircase and elevator core. Each flat is centred around a sanitary core with kitchenette and bathroom.

These are flanked on one side by the living room and on the other by two bedrooms. Depending on the storey, the flats have varying aspects. For example, all the living space on the ground floor faces the courtyard. Whereas on the first floor, it overlooks the street below, offering views of the Serra de Tramuntana mountain range. Each flat on the second floor has an additional inward-facing patio besides a balcony on the other side.

Flexible skeleton design

The building structure is a mesh-like system of concrete slabs with large spans and a thickness of 35 cm which are painted light green. One benefit of this design is the shorter construction time, but it also enables the building to be easily adapted to future needs. The façade has a double ceramic layer with insulation made of recycled cotton, and its external insulation consists of sprayed cork and coarse lime. These were developed by local companies. Folding larch wood sun shields on a thermally independent aluminium substructure provide shade in the summer.

“IBAVI’s specification was to use local, natural materials wherever possible, and this was a challenge,” admits architect Marc Alventosa. “Such specifications usually encounter resistance from the construction industry.” It was the first time that these two architectural firms had to reduce the ecological footprint for a multi-family project, and also ensure that materials could be recycled.

Only half the footprint

Nonetheless, the planners mastered their challenge with ease. Just in terms of the materials, using local clay, ceramic façade elements, recycled cotton for the insulation, sprayed cork and coarse lime for the exterior insulation as well as larch wood for the sun shields enabled carbon emissions to be cut in half compared to buildings with similar characteristics. “Besides that, we didn’t just check the materials, but also how they were produced,” explains architect Joan Fortuny Giró. “For example, the interior floors are made of biomass-fired clay ceramics.”

This means that materials production also conformed to the principles of closed-loop recycling and was – as far as possible – adopted by the local industry and craftspeople. Where wood or recycled aluminium were unfeasible, the architects chose construction materials with a very low carbon footprint.

The second major challenge was the site chosen for 54 HPP Inca. “Its proximity to train tracks and the strong sunlight motivated us to choose a rear-ventilated façade with wooden sun shields. These have enabled us to protect residents not just against heat, but also against noise pollution from trains,” explains Marc Alventosa. The sun shields – made of sustainably forested, certified larch wood and produced by local craftspeople – can be folded out and in. As a prominent feature of the property, they define its outward appearance. Aluminium window- and doorframes painted mint green deliver an added, colourful statement.

Looking good for the environment

And the third challenge? “One of our main concerns was to reduce the construction to the bare minimum. Not just to lower its ecological footprint, but also reduce the financial burden,” emphasize the planners. Indeed, their cost saving is plain to see. For instance, the garden fences are simply reinforcement steel mesh. Brick dividing walls inside the flats are merely painted, and the ceilings are plastered with perlite insulation. False ceilings for the installation cables are only found in the bathrooms.

Nevertheless, 54 HPP Inca has a fascinating appeal: ceramic panelling around the base of the building towards the street is continued in the courtyard as unplastered garden walls of vertical coring bricks. The light-green balcony balustrades and windowframes – matching the façade supports – contrast refreshingly with the cream-coloured lime plastering and surrounding natural shades.

“Right from the outset, the structural solution was designed to integrate bioclimatic strategies such as thermal mass and heat resistance,” explain the planners at Fortuny – Alventosa Morell. Organizing the two sections of the building along a north-south axis and also in an L shape is just one example here. Firstly, this created a courtyard with shared use. But in particular, the location of the living space and bedrooms was planned with climate factors in mind – such as sunlight and the wind. This also gives the flats their dual aspect.

Passive strategies

Further passive strategies reduce the energy needs for heating and cooling. In addition to normal window ventilation, the houses are equipped with central ventilation systems with heat recovery. These provide the flats with fresh air at 24 °C throughout the year. The systems were placed on flat roofs covered in recycled gravel, which increases their lifespan. PV panels, heat recovery units and ventilation ducts are fitted on top. Vertical ventilation ductwork runs through two installation shafts on both sides of the bathrooms.

“All flats feature high thermal inertia in the floors and walls as well as materials that regulate humidity hygroscopically and allow for breathability,” says Joan Fortuny Giró. He and his partners also chose renewable energies to heat and cool the buildings: warm water is provided by an aerothermal system, and ventilation uses a heat exchanger. Together, all of these measures achieve a low-energy building that requires 0.64 kW per square metre and year. However, the project’s NeZB efficiency is not its sole response to the climate crisis. Its water cycle and a 20 per cent reduction in the volume of waste compared to theoretical production are remarkable as well.

Courtyards, patios and private gardens make it easier to ventilate the flats as well. And vegetation – native plants such as Jacaranda trees – additionally regulates the sunlight, temperature and humidity. Aside from this, the architects took a low-maintenance approach to the outdoor areas: recycled gravel allows better permeability and enables plants to absorb the water. Furthermore, rainwater from the roofs and patios collects in cisterns and can be used to water the greenery where required.

Political support

Tenants have reported that their new flats are a good place to live. For the planners, out of all the goals they needed to fulfil, this is the best result of all. Ultimately, the architects at Fortuny – Alventosa Morell emphasize that “we believe every person has the right to enjoy high-quality living space, regardless of their financial situation.”

Luckily, the region’s politicians agree. At a press conference in May 2023, the President of the Baleares at the time, Francina Armengol, made it absolutely clear that neither Mallorca nor its neighbouring islands needed even more luxury apartments or tourist accommodation. Instead, they need living space that locals and the planet as a whole can afford.

“It isn’t easy to change the construction sector in the direction of an ecological and socially responsible industry,” Marc Alventosa and Joan Fortuny Giró remarked. “But it is a motivating challenge.”

54 HPP Inca shows how to produce the right results.

Text: Daniela Schuster
Translation: Rosemary Bridger-Lippe
Images: José Hevia