Multi-active façade for Swedish multi-family homes renovation: Evaluating the potentials of passive design measures

In order to meet the Swedish energy efficiency objectives for the built environment until 2050, a particular building stock has to be addressed: the houses of the Million Homes Programme, an ambitious housing programme of the 1960s and 70s that resulted in a large number of standardized multi-family houses all over Sweden. These are in need of upgrading the energy and comfort quality to current standards, which provides an excellent opportunity to investigate the potentials of ‘prefabricated multi-active’ façades for refurbishments on large scale. While ‘prefabrication’ is linked to cost-effectiveness and high replicability, ‘multi-active’ addresses the potential of embedded active and passive measures for improved energy efficiency and energy regulation out of the façade. Integrated building services technologies, solar technologies or moveable components, such as shading systems, are considered active measures. Passive measures include physical and constructive measures, such as e.g. thermal insulation or selective coatings of glazing’s, and provide a “passive” energy flow control to improve the thermal quality of the building envelope. Many of these strategies are well-known, traditional solutions. Although they do not provide an energy-generating or -supplying function, they dynamically interact with environmental changes; preheating of supply air through the air cavity of a façade construction or adaptive thermal buffer zones are just few of many examples. The question is how traditional passive strategies can be used to contribute most effectively to the demanded energy efficiency. The paper presents first results from an assessment dealing with this question: Two traditional ‘passive’ façade strategies, a curtain wall system and closed balconies, have been analysed in regards to their impact on energy balance and their thermal behaviour in a defined renovation scenario. The assessment is aims to support the development of a multi-active facade concept suitable for large-scale refurbishments of the multi-family houses in Sweden, which is part of the initial phase in the pre-study “Multi-active façade”. The pre-study considers architectural, technological and constructive aspects, energy performance and indoor comfort optimization, but also economic feasibility and constraints to get replicable on large scale. So-called added values that concern the upgrade to modern living standards and expectations by inhabitants and the market value of the building are also touched. The paper discusses, based on a technology screening to identify suitable key measures, the energy saving potential and impact on thermal indoor comfort of two passive renovation strategies for facades

The Design of an Energy Efficient Highly Glazed Office Building

Many modern office buildings have highly glazed facades. Their energy efficiency and indoor climate is, however, being questioned. Therefore, when a modern office building (new construction) with larger glazing areas was planned, an investigation was carried out to determine the possibilities to: - efficiently use the increased access to daylight and thereby reduce the use of electricity for lighting and at the same time improve the visual comfort - ensure good thermal comfort - arrive at a reasonable total energy use, which is at the same level or preferably lower level than a traditional office building. The work was done by a project group that supported the design team with advanced energy, indoor climate and daylight simulations. Detailed performance specifications on energy use and indoor climate were worked out. The results show that the aims can be fulfilled if the following main requirements are fulfilled: - The glazing area should not exceed 45 % of the façade area. - The total solar transmittance of the glazing combined with solar shading must be lower than 0.1. - The U-value of the windows must be lower than 1.1 W/m²K. A double skin façade was chosen. An important conclusion is that coordination and cooperation throughout the building process is absolutely necessary. The building will be finished in 2007

Best practice guidelines for double skin facades

Many modern office buildings have highly glazed facades. Their energy efficiency and indoor climate is, however, being questioned. Therefore more and more of these buildings are being built with double skin facades, which can provide: a thermal buffer zone, energy savings, wind protection with open windows, fire protection, aesthetics, solar preheating of ventilation air, sound protection, pollutant protection with open windows, nocturnal cooling and a site for incorporation of PV cells. However not all double skin facades built during the last years perform well. A project BESTFACADE was therefore funded by the European Commission to actively promote the concept of double skin facades. An important part of this work is the creation of best practice guidelines for double skin facades, which are outlined in this paper

The energy performance of glazed office buildings with double skin facades - BESTFACADE

Many modern office buildings have highly glazed facades. Their energy efficiency and indoor climate is, however, being questioned. Therefore more and more of these buildings are being built with double skin facades, which can provide improvements: a thermal buffer zone, energy savings, wind protection with open windows, fire protection, aesthetics, solar preheating of ventilation air, sound protection, nocturnal cooling and a site for incorporation of PV cells. However not all modern double skin facades perform well. A project BESTFACADE, was therefore partially (50 %) financed by the European Commission to promote well-performing concepts of double skin facades. The paper summarizes the best practice guidelines

Energi- och Miljörenovering av miljonprogramshus - Backa Röd i Göteborg

I Sverige finns ett stort bostadsbestånd som står inför ombyggnad. Miljonprogrammets bostäder är över 40 år gamla och behöver rustas upp. Det är angeläget att denna upprustning utformas på ett sådant sätt att husen byggs om till energieffektiva byggnader med låga framtida drifts- och uppvärmningskostnader och med låg miljöpåverkan under hela livscykeln. Det är i sammanhanget viktigt att energieffektivisering av byggnaderna genomförs samtidigt som husen renoveras för att åtgärderna ska kunna genomföras till rimliga kostnader. För detta behövs nya metoder för kostnadseffektiv energi- och miljörenovering. Sverige deltar i ett internationellt forskningsprojekt med detta syfte, IEA Annex 56

Tenants Acceptance or Rejection of Major Energy Renovation of Block of Flats - IEA Annex 56

To meet EU energy and climate targets, energy efficiency of the existing building stock must be drastically improved. Within IEA EBC Annex 56 one of the best practice examples of energy renovations is a group of multi-family buildings in Sweden, recently thoroughly renovated. For this group of buildings the residents' perception of renovations and appraisal of implemented measures were captured by interviews with tenants and a literature review. Residents' possible acceptance of energy renovations are related to improvements that are directly experienced and visible. Resident participation is beneficial. Crucial is the collaboration between all stakeholders. Long-term environmental benefits or financial gains are arguments that might not be sufficient