Case 2: Medianeras, Barcelona


Case parameters:

Type of construction: renovation
Typology: Residential
Owner: city- local administration / combination with private property
Construction systems: PnP
Location: Spain, Barcelona

The challenge we face

“Medianeras” are bind walls that separate two different buildings and are opaque because there is traditionally a possibility that the neighbouring building will be constructed higher, so there is no prevision that the wall will stay visible. However, there are locations where no new or higher construction isn’t possible anymore due to the urban planning regulations change, occasionally combined with demolition of the neighbouring buildings, so the medianera walls stay permanently uncovered. In this case, the medianera wall is considered as “consolidated” by the regulation “Ordenanza de los usos del paisaje urbano de la ciudad de Barcelona Acuerdo del Consejo Plenario, 1999” by the Barcelona City Council.
These walls strongly impact the urban environment. Currently in Barcelona, Spain, most of the medianera walls represent the unfinished aspect, either showing the original building construction, residuary wall finishing after building demolition or provisional finishing, represented by the cheapest and simplest materials like polyurethane insulation or simple rendering and paint. There are still cases, where the asbestos has been used in the fibercement ventilated façade system, presenting serious health risks (in Spain, its use was prohibited in 2001 by anexo I del Real Decreto 1406/1989, however the treatment of the existing applications was not resolved.)

Other resulting problems of these little durable solutions are discontinuity and subsequent disintegration of the finishing and humidity problems and cracks with related structural problems. In singular cases, the medianera walls gave opportunity for urban art paintings or application of green walls. In few other cases, where the walls are exposed to public and/ or car drivers, the surface is used for advertisement. Depending on the building constitution, the medianera wall can occupy a considerable part of a flat’s envelope and therefore strongly influence its energy efficiency and comfort conditions.  These medianera walls can be a shared property of the city local administration or housing association, while the building itself can have the same owner, or a private owner, or a collective of owners, which historically meant a problem because of the lack of definition of who’s responsibility was the correct state of the medianera wall The problem is solved nowadays by the obligation of assuring the required state of the wall as part of the renovation or demolition process which originated the existence of a new medianera. However, there is a large stock of the existing ones.

What we will do

In this demonstration case, The Institut del Paisatge Urbà of Barcelona has already been promoting a program for rehabilitation of the Medianeras, where suitable projects will be selected in 2019 with the prevision to be built in 2020. It promotes the renovation of medianeras through architectural projects of integration.  The goal is to give meaning to these places where the social and cultural identity have been lost. The program is supported by financial aids coming from public sources, as well as by private sponsors. The public-private partnership is encouraged. The Institute has agreed to fully engage in providing a demonstration site, where there would be the possibility to validate the proposed system by monitoring, as well as perform a user satisfaction survey. With Drive 0, we will:

  • Foster circular economy, including reusability of existing construction materials.
  • Raise public consciousness about the circular economy
  • Raise the knowledge and experience of the local actors in the construction processes in the circular economy and practical application of its principles, to support the adaptation of the sector to the circular economy

The results we expect

In Spain, we expect to see the following results:

Case specific outcomes:

  • Reduction of the embodied energy (in % compared to current deep renovation) triggered by the project; focused on materials with high durability, reusable and recyclable
  • Detailed LCA and LCC control of the applied materials and technologies; life cycle cost in Euro/sqm
  • Training of the local actors, acquiring skills necessary for design, manufacturing, installation and maintenance of systems based on circular principles; Number of trained personal of the construction process actors
  • Raising the awareness of the public by showing off the result of the renovation process with the minimized impact, visual impact by applying green elements and energy production elements to the medianera façade + workshops and conferences
  • Quantified environmental impact
  • Installation time reduction in % compared to traditional construction process

Case specific impact indicators:

  • Energy performance improvement resulting in an energy consumption of 15 kWh/m2 per year.
  • Overall life cycle cost reduction of 25-30% compared to current deep renovation strategies, based on a high level of prefabrication using local materials, with high durability
  • Reduction of time needed on site for renovation works, due to the prefabrication off-site techniques, allowing minimized user disruption
  • A reduction of the greenhouse gases emissions (in tCO2-eq/year) and/or air pollutants (in kg/year) triggered by the project; the DRIVE 0 concept results in a potential decrease of C02 of 180,000 tons of C02 annually.