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65% of the buildings in Västerås, situated in the region of Mälardalen, Sweden were built before 1970. It is thus time for renovation. The situation is the same in most cities in Sweden and Northern Europe. The depth of renovation can be quite different. In this paper we evaluate some examples where cost is compared to energy saving effect. How to plan renovation to make use of the available capital in the cities is discussed. As a complement to direct renovation actions also behavior change with respect to energy is discussed and exemplified. The cost for energy actions in relation to other renovation aspects is discussed especially for the passive house case in Allingsås, Sweden. The passive house center calculate an extra cost for passive house standard to be 10 000 €/apartment while an external consultant has the figure 40 000 € of the total cost of 120 000 €. With this space heating can be 18 kWh/m².year, or a reduction by 84 % with respect to space heating and 62% for overall heat and hot water demand. If you use the latter cost figure passive house standard is not motivated from an energy savings perspective while if using the lower figure it is very interesting. For the other less deep renovations we see that adding more insulation and three glass windows is motivated if the degradation has been strong, while a simpler renovation may be ok if the outer surface coating is not too bad. For these less deep renovations we see cost figures of 65 €/m² respectively 28 €/m² with reduction of heating and hot water demand of 56 % respectively 34 %. [ABSTRACT FROM AUTHOR]

Our proposal is to enhance information on the actual building stock and on barriers and drivers that influence the decision of public or private buildings ‘owners toward renovation. With this information and with dedicated services, local authorities could persuade owners to undergone renovations on their buildings. We developed a methodology that allows to create a GIS model and tools quickly for virtually every Italian municipality and already tested in an Italian medium size municipality. With these tools it is possible to select buildings that need most the renovation and buildings that could be more easily renovated, considering barriers and drivers. [ABSTRACT FROM AUTHOR]

Refurbishing existing buildings plays a key role in reducing the overall energy consumption of the building stock. The use of prefabricated timber façade elements in the renovation of buildings is often beneficial due to their limited thickness and weight, the integration of HVAC and windows, the functionality and speed during works etc. Despite these proven benefits, these systems are not commonly used in Belgium. The research project of which this work is part of, therefore aims to stimulate the use of these elements for renovation by eliminating technical barriers that may hinder their use. In this paper, the impact of different design choices on the hygrothermal performance of elements that are installed in front of an existing façade, e.g. a cavity wall, is evaluated. The protection of the existing inner cavity leaf after demolition of the outer cavity leaf, the integration of a vapor retarder between the new element and the existing construction and the use of cellulose insulation proved to be advantageous measures to reduce the risk of degradation. [ABSTRACT FROM AUTHOR]

The industry standard ByggaF is a method developed in Sweden to improve the moisture safety during the entire building process. This work suggests adjustments of ByggaF to improve the current use in the construction industry as well as better suit the renovation process. The main focus of this paper cover adjustments of the method in the program and design stage. [ABSTRACT FROM AUTHOR]

Solar concepts show potentially an improved cost-performance (energy) ratio when applied as the integrated parts of building renovations. This paper reported a compact solar thermal facade (STF) module with the internally extruded flow channel suiting for solar renovation concept in buildings. A few of impact factors were considered for the parametric study in order to optimize the STF's configuration for various applications through the validated simulation model. The overall research results are expected to be useful for further improvement in the thermal performance of solar renovation measures. [ABSTRACT FROM AUTHOR]

A national programme of research was carried out in Finland to explore a concept for renovation of apartment blocks. The aim of the project was to develop an industrial-scale, economical and efficient concept for renovating, expanding and adding floors to apartment blocks. The technical solutions forming part of the concept make effective use of the opportunity provided by new Finnish fire regulations to use wooden structures when renovating. The apartment blocks built between the 1960s and 1980s now need to be renovated. One alternative that has come to light for the covering costs of renovations is additional construction. Buildings often have flat roofs, which makes the addition of a floor both architecturally and technically easier. Prefabricated modular units were developed in the project in cooperation with the industry. The size of the units chosen has implications for structural planning as well as for the planning and implementation of the construction site and installation. Prefabricated wood-framed units can be installed on existing concrete slab. The direction and placement of the units are usually determined by the location of the load-bearing structures below. Installation of an array of beams upon the roof of the original building is often the best solution. The beams distribute the load from the new units over the old structures. [ABSTRACT FROM AUTHOR]

In a new product development project numerous decisions are made that influence the course and the outcome of the project. Remarkably, little research is done on how decisions in new product developments are actually made and how the decision making affects the performance. This research contributes to closing this gap of knowledge by comparing the decision making of two new product development projects. This study provides insight in the importance of various decisions and how successful decisions should be made. The study contributes to the new product development literature through extensively studying the use of decision making styles in two product development projects of transformation concepts. The empirical findings emphasize the importance of understanding the context of projects and the way decision should be made to be successful. [ABSTRACT FROM AUTHOR]

In this paper, the influence of construction details on the overall thermal insulation and energy demand in Belgian houses is examined. The research was carried out for 12 archetypal Belgian single family houses. For each house, nine typical construction details were selected. The Flemish EPBD method was used for an energy performance simulation before and after refurbishment. It can be concluded from this research that window joints refurbishment has a bigger impact than any other joint refurbishment. Another observation is that that the reduction of energy consumption due to refurbishment of construction joints is not linked to joint length. [ABSTRACT FROM AUTHOR]

This study presents the challenges of monitoring energy consumption to assess behavioral changes in occupants during renovation projects and how to develop a strategy to overcome those challenges. Three buildings containing seventeen flats in total were monitored during a period of over two years, monitoring energy consumption and internal temperature of the flats. The energy consumption for the flats was capture by the use of a Current Cost smart meter placed at the ground floor of each block of flats in a cover under stairs. Wireless sensors were clamped to each flat. The smart meters were not connected to the internet or a computer, but instead the data was stored in the internal memory of the equipment and manually downloaded to a computer at each data collection visit. For the purpose of double checking, meter readings were collected at the electricity meter to be able to compared the accuracy and success of the data collected by the Current Cost smart meters. The internal temperature of every flat was collected by mean of a LogTag temperature data. From comparing the Current Cost smart meter data versus the utility meter readings a huge range of overestimation and underestimation of the actual energy consumption was observed. Regarding the internal temperature monitoring, long periods of lost data was identified. The main factors contributing to these data lost were: Long periods between data collection, wireless signal drop offs, unplugging, tampering and removal of equipment. A normalized energy index, based on utility meter readings, internal temperature and outdoor conditions, was developed to overcome the loss of data and assess the effectiveness of the technology and the behavioral change in the occupants. The normalised energy index provides a methodology to evaluate technology and behavioural changes effect between flats and across seasons. [ABSTRACT FROM AUTHOR]

The Swedish housing stock is once again in focus for national energy savings, as it was after the oil crises in the 1970s and 1980s. The contemporary debate has a one-sided focus on energy savings and barriers for implementation of existing energy efficient renovation measures but also on large stock of industrialized housing built after 1960. The need for renovation is equally urgent in older stocks of housing, also in those that already have been renovated but are in need for further interventions. In this paper we focus on multi-residential housing built before 1945 in Gothenburg, Sweden, representing cultural and historical heritage values. The opportunities to ensure high energy efficiency with new measures in a second renovation should aim to find a balance with heritage values, social values, function, aesthetics and management aspects. In order to get an understanding of the conditions of the stock in focus, we apply both a top-down and bottom-up approach. In the top-down approach, data are gathered from different sources such as energy performance certificates, the national property register, and geodata from the City of Gothenburg. By combining information from these databases, three data subsets have been defined for the bottom-up approach: non-renovated buildings, buildings renovated to a small extent and buildings renovated to a large extent. Three case study buildings were selected out of these data subsets. The choice of renovation strategy differs between the cases. Case study building 1 has been left virtually untouched while case study building 2 and 3 have been renovated to different extent. The next step in this research project is to identify suitable renovation alternatives for these building typologies. [ABSTRACT FROM AUTHOR]

Prefabricated elements to provide environmentally friendly, energy- and cost-efficient solutions for the building envelope have been studied. The newly developed element system has a high level of flexibility since it is possible to adjust the length of the connection rods according to the building's energy requirements and it can be mounted on timber, concrete and brick structures. Adjustability to different types of buildings structures, materials, tolerances, geometries and energy requirements makes it very applicable and efficient. [ABSTRACT FROM AUTHOR]

The energy efficient renovation of the Solitude-Gymnasium in Stuttgart is one of the 4 demonstration buildings within the EU 7FP project “School of the Future”. The secondary school with about 710 pupils consists of a typical configuration with a main building, a building of scientific classes, a big pavilion, a small pavilion and a gym, built between 1966 and 1975. The main building and the gym include flats for the caretakers. The total heated floor area of the buildings amounts to 8,924 m 2 . The exterior walls of the buildings are made of exposed concrete or brick. All buildings have flat concrete roofs that had no sufficient insulation before the retrofit. Most windows consisted of PVC-frames and double-glazing, but in some corridors and stairways single-glazed facades existed. The heating was generated centrally for all 4 buildings by two gas boilers that replaced an earlier system in 2004. Domestic hot water for the gym is generated by a heat exchanger based on the heating water. Ventilation systems without heat recovery existed for some indoor rooms, some rooms in the building of scientific classes and the gym. All 4 demonstration buildings in the School of the Future project have the same goals: • Reduction of the total energy use > factor 3, verified through monitoring • Reduction of the heating energy use > 75%, verified through monitoring • Improvement of the indoor environment quality (air, daylight, acoustic, thermal comfort) with impact on the pupils’ performance, analysed by short-term measurements and questionnaires The building envelope renovation measures at the school in Stuttgart included external thermal insulation systems and curtain wall facades with 14-18 cm polystyrene insulation, 16-22 cm of expanded polystyrene on the roofs and mostly triple-glazed windows. The new heating system is a co-generation plant in combination with the existing boilers. The ventilation of the classrooms is now realised by decentralised ventilation units with 80% heat recovery (main building) or by hybrid ventilation consisting of window opening supported by actuators at the upper part of the windows that are controlled by timers and manually by the teachers. CO2 visualisation systems show the teacher when window opening is necessary. The existing ventilation system in the building of scientific classes are improved by central heat recoveries of 80% - 90% efficiency. Also the lighting system was updated by T5 compact fluorescent lamps, electronic ballasts, daylight control and presence detectors. A one-year monitoring period will show whether the energy performance goals (reduction of final energy from 225 to 58 kWh/m 2 yr and primary energy from 215 to 54 kWh/m 2 yr) and the indoor comfort goals can be achieved. [ABSTRACT FROM AUTHOR]

To meet EU energy and climate targets, energy efficiency of the existing building stock must bedrastically 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. [ABSTRACT FROM AUTHOR]

In the current study potential for finance and energy savings of detached houses in Estonia is calculated by combining five real average example buildings, five bundles of original building envelopes, six types of heat source, and three ventilation systems to represent the building tradition from five time periods. Measures analyzed are additional insulation of the building envelope and change of heat source for space heating, ventilation, and domestic hot water. The influence of renovation measures on the energy saving was calculated with the multi-zone indoor climate and energy simulation program IDA Indoor Climate and Energy, with the standard use of the building. The economic effect of the renovation measures was assessed through a balance of investment cost and energy savings. It was found that the installation of the mechanical ventilation system with 60% or 80% heat recovery is the most cost effective measure. In newer houses, the replacement of an ineffective heating system was found to lower the global cost of the house. [ABSTRACT FROM AUTHOR]

In Norway, a large portion of the building stock originates from the period from 1955 to 1990. Many of these buildings fail to comply with the current building regulations regarding the energy consumption. In this study, the possibility for upgrading a hypothetical apartment building with an oil-based heating system has been investigated employing simulations from the IDA Indoor Climate and Energy software. For the construction of the original building, customs and regulations from the period 1981-90 were employed, and the building envelope was upgraded to the requirements of the Norwegian research centre on Zero Emission Buildings. Two alternative heating systems have been investigated: solar thermal collectors (i) alone and (ii) as combined with borehole thermal storage and a ground-source heat pump. For each case, the energy consumption, thermal comfort and indoor climate were studied. The simulations predict a reduction in the total annual heat demand to one third of the original with the upgrading. For the alternative heating systems, with solar collectors alone the demand for additional electric heating was still considerable, however in the combined system it was negligible. Regarding thermal comfort, in the upgraded building longer periods with elevated temperatures were observed. [ABSTRACT FROM AUTHOR]

Abstract: In theory, there is huge potential for reducing the energy consumed by existing single-family houses by thoroughly renovating them. For the successful market development of highly energy-efficient integrated renovations, supply chain collaboration is very important, while at the same time customer demand for integrated renovations has to be stimulated. A research and networking methodology was developed within the framework of the One Stop Shop project to identify and develop collaboration opportunities for advanced housing renovation in Belgium, Denmark, Finland and Norway. The research identified key supply-side needs through interviews and questionnaires, and analysed important elements for the development of a web-based portal that can connect supply and demand. The project further developed ideas and methods for collaboration and business model generation between different players on the renovation market. These different research results contributed to defining new business opportunities related to process innovation to unburden the homeowner and to achieve less fragmented renovation processes. [Copyright &y& Elsevier]