Case Study: nZEC - New construction of 95 dwellings in Carrer de Roc Boronat, Barcelona, Spain (UNDER MONITORING)
Name of organisation: PMHB - Patronat Municipal de l’Habitatge de Barcelona
Stage of development: completed
Year of finalization: 2012
Type of project: construction
Area: urban
Scale: group of buildings
Type of building: Apartment in a block of six to ten stories
Number of units/dwellings: 95
Tenure: social rental
Street: C/ RocBoronat
Postcode: 08018
City: Barcelona
Region/ County: Catalonia
Country: Spain
Last Update: 20.04.2015
Short Description
The building developed by the PMHB is the first multifamily building in Barcelona that has obtained the highest energy rating. The promotion was designed by the architect team SaaS.
The 95 homes are distributed on three different scales: 7 floors, 6 floors and 3 floors, with a distribution from 4 to 9 apartments per floor. The homes size range goes from 45 m2 to 78 m2. The building has a total area of 12297 m2 and a budget of € 10,155,266.The building is a single volume with a triangular shape.
The volume has holes in two points, where courtyards are placed; these spaces are used to access to the building from the street. The dwellings have being designed focussing on medium size families including two or three bedrooms per dwelling.
The structure is arranged on the circumference with semi precast concrete slabs, allowing the housing to be released of structural elements. The facade is a ventilated façade with a double skin formed by sunscreens sliding wooden slats.
Key Elements
Project Management
The building has access to the first district heating and cooling network of Spain, Districlima. This system will represent a 20% saving on consumption of electricity and a 50% reduction in CO2 emissions. It is based on the use of the residual steam of the energy revaluation of the urban waste for heating and on the use of absorption refrigeration machines cooled by sea water for cooling. Besides the Districlima there are incorporated other building systems that improve energy efficiency, as higher insulation than the one established by law, ventilated facades, windows with sun protection mechanisms, economizers taps, tanks for bithermal appliances installation, presence sensors, low-power lifts, etc…
Thermal Insulation
To reduce the energy demand, the building has a much higher insulation thickness than the one required by the legislation, with a minimization of thermal bridges, thereby achieving a thermal transmittance of walls less than 0.3 W/m2K. the façade consist of a sandwich panel structure and a galvanized drywall, doubled externally with a ventilated facade that improves the summer comfort thus guaranteeing exceptional hygrothermal conditions (improving insulation capacity, the inertia and the vapor permeability).
Windows and Shading
The windows have sunscreen sliding wooden slats that create a second skin which can be move depending on the needs and preferences of the users. On the street side, this second skin is separated from the front creating small balconies.
Heating and Hot Water
For hot water the building has an installation of solar thermal panels on the roof. For heating and for the support of hot water, the building is connected to the district heating and cooling network Districlima (previously explained).
Cooling
For cooling, the building is connected to the district heating and cooling network Districlima (previously explained).
Solar Thermal
For hot water the building has an installation of solar thermal panels on the roof.
Other Renewables
As explained before, the building has access to the first district heating and cooling network of Spain, Districlima, which is based on the use of the residual steam of the energy revaluation of the urban waste for heating and on the use of absorption refrigeration machines cooled by sea water for cooling. Although this system is not classified by law as renewable energy, the philosophy is the same.
Electricity Saving Products
The dwelling have the possibility of placing Bithermal dishwasher and washing machine, allowing the use of water heated by solar energy rather than water heated by the electrical resistance incorporated in the appliance. The activation of the lighting of the common areas is with presence sensors and the lifts are low energy consumption.
Water Saving
The dwellings have incorporated measures to reduce water consumption as tapslever mechanism with economizer and water cisternstoilets with dual flush mechanisms.
Monitoring
Click here to access the monitoring data on the HIVE Database!
Main Results
The project design was complex in the absence of precedents connecting public housing projects to the district heating network. This meant that the Patronat had to add the connection to the network in the project and they also had to discard the solar panels. Finally, the adoption of centralized DHW, heating and cooling systems in public housing buildings added more technical partners, making the whole process more complex.
Lessons learned
The experience of connection to the district heating network of a residential building has been positive. The decision simplifies indoor facilities, reduced spaces for boilers and accumulators and disclaims the placement of solar panels. In about six months of occupation the system has been well received by users. However, Barcelona has not culture with such facilities and the mild climate for most of the year allows other efficient alternatives to such urban infrastructure. The Patronat believes that, in multi-family housing buildings, it is better to work in reducing energy demand (passive systems), in installing ventilation systems with heat recovery and solar panels for DHW.
Additional Information
Ms Maria Jesús Gascó
AVS - The Spanish Association of Social Housing and Land Providers
E-mail: mjgasco@promotorespublicos.org
Web: www.promotorespublicos.org