Rainha Dona Leonor renovation

Location: Porto, Portugal

Population: 287,591 [city area]

Climate: Mediterranean

Duration: 2009 – 2014

Sector: Buildings

Funding sources: Public

City networks: Covenant of Majors

Savings: Energy savings as well as CO2 reductions.

Solutions: Renovation intervention on the smaller multifamily buildings of the Rainha Dona Leonor neighbourhood.

Multiple benefits: Reduction of energy consumption, increased production of renewable energy, reduction of CO2 emissions and increased quality of life for local residents.

Rainha Dona Leonor is a neighbourhood of 150 social multifamily dwellings built-in 1953. The buildings, made up of concrete structure, brick walls and lightweight slabs, had never been upgraded, which led to a profound state of degradation of the neighbourhood. The city council had to decide whether to undertake deep renovation works or to demolish the buildings. In 2009, Porto’s City Council opted for deep renovation and decided to reduce the total number of buildings in Rainha Dona Leonor from 150 to 90.

Objective – To carry out a deep renovation of the neighbourhood of Rainha Dona Leonor.

Solutions – Even though energy consumption was not a main concern during the deep renovation process, the municipality of Porto had to comply with current thermal regulations. Therefore, new heating and cooling facilities, as well as domestic hot water systems based on solar thermal energy were installed, resulting in the improved energy performance of the building envelope.

1) Technologies: Exterior walls insulation, Roof insulation, Introduction of double glazing windows, Daylighting improvement with bigger windows in the living room, Efficient heating and cooling systems, Solar thermal system for domestic hot water (DHW); 2) Building ─ Wall: External insulation and wall renovation with 60mm of EPS covered by reinforced plaster; ─ Roof: Insulation with 50mm XPS panels; ─ Windows: Wooden frames + double glazing with 4mm and 6mm; 3)Systems ─ HVAC: Multi-split air conditioning system with a coefficient of performance (COP) of 4,1 for heating and energy efficiency ratio (EER) of 3,50 for cooling, on each flat. ─ Lighting: Improved daylighting with larger windows. ─ Renewables: 3m2 of solar panels for DHW, per flat. ─ DHW: New electric heater with storage tank

Funding – Renovation of the Rainha Dona Leonor neighbourhood was completed in 2014 and funded through Porto’s own resources, €17.3 million invested by the 4 municipalities

Innovation – The overall improvement of the neighbourhood allowed to transform this neighbourhood into the best social neighbourhood of Porto city according to the evaluation of the municipality, with comfort and livability conditions much better than other recently built neighbourhoods.

Success factors –  A successful decision process was carried out, where different barriers were overcome: 1) The lack of financing to carry out the works at once; 2) Strong discussion whether the best solution was to renovate or to demolish and transfer tenants to other buildings; 3) The need to have the buildings vacant to carry out the renovation works.

Significant outcomes:

• 70% decrease in energy costs for the residents;
• An annual CO2 -emission reduction of 12.9 tons and yearly primary energy savings of 286.54 kWh/m²;
• The improvement of the building envelope and the control of infiltrations led to an annual reduction in energy needs of 49.78 kWh/m²;
• The increased uptake of renewable energy by using solar thermal yearly contributes to 9.96 kWh/m² of the neighbourhood’s energy consumption.

Synergies with local policies:

• Porto´s Sustainable Energy Action Plan (SEAP)  aims to become an energy-efficient city by 2020. It defines the actions towards achieving the 45% CO2 reduction target (compared to 2004 levels). It assigns a high priority to demand management (i.e. improvement gained from rehabilitated or new buildings).

 Political alignment:

• National Action Plan for Energy Efficiency (NEEAP) 2016 has estimated savings until 2016 of 1501 ktep (in final energy), corresponding to a reduction in energy consumption of approximately 8.2% compared to the average consumption verified in the period between 2001 and 2005. The establishment of the 2020 time horizon for the purpose of following up and monitoring the estimated impact on primary energy consumption makes it possible to anticipate in advance the fulfilment of the new targets assumed by the EU, of a 20% reduction in primary energy consumption by 2020, as well as the objective general assumed by the Government of reduction in the consumption of primary energy of 25% and the specific objective for the Public Administration of reduction of 30%.
• The National Action Plan for Renewable Energy for the 2013-2020 period (PNAER 2020) sets the target of 31% for the use of renewable energy sources in gross final energy consumption and 10% for energy consumption in transport, by 2020.

Long-Term Strategy for Carbon Neutrality of the Portuguese Economy in 2050 sets as an objective, for the reduction of greenhouse gases (GHG) emissions for Portugal between 85% and 90% by 2050, compared to 2005, and the compensation of the remaining emissions through the use of soil and forests, to be achieved through an emission reduction trajectory between 45% and 55% by 2030, and between 65% and 75% by 2040, in relation to 2005 [source]