Buildings represent the largest untapped source of cost effective energy saving and CO2 reduction potential within Europe. More than 40% of Europe’s residential buildings predate the 1960s, when building energy regulations were limited; the majority of these buildings have not been brought up to modern energy standards. However, currently, the rate of building renovations in the EU comprises just 1% of the building stock, with only a small proportion of this activity comprising so-called deep renovations. Despite considerable market size and EU mandated retrofit targets, the sector continues to suffer from significant underinvestment, the market has not realized its full potential and a wide range of actual and perceived barriers impede stakeholders. For Energy Efficiency Conservation Retrofit (EECR) project actors, the challenge is to respond to this new business environment, while maintaining adequate value for stakeholders. For housing property actors, this means a growing impetus to understand the value propositions of other EER stakeholders and to consider new, innovative ways of doing business. The Business Model concept refers to organizational logic through which companies operate, defining the manner by which enterprises deliver value to customers, entice customers to pay for value, and convert those payments to profit. This paper posits that new collaborative approaches to developing business models are required to plan EECR projects such that value generation is maximized while value capture is satisfied.
The aim of the paper is filling the gap in the existing Italian literature on the quantitative determination of FV. The concept of FV is generally defined in comparison to the Market Value (MV) of a property. By an empirical investigation, we identify the quantitative relationship existing between these two types of value and analyze the determinants of the Italian real estate forced sale auction market.
Collective Self-Organized (CSO) Housing (referring to both renovation of existing stock and construction of new dwellings, with the definitive influence of the residents) has become the center of attention of public authorities and private businesses alike, the main reason being that it is often considered a good solution to open up new market segments in the post-crisis housing market for all stakeholders involved. Many of these CSO Housing projects seem to strengthen the commitment of residents to their own built environment. They furthermore contribute to the development of precisely the kind of housing that meets the requirements of the involved clients. This way, the emerging tendency of collective participation of end users in their future built environment contributes to a more accepted, sustainable, green and social environment for many residents to live. The applicability of CSO Housing solutions is strongly dependent on many factors. First and foremost, new CSO Housing constructions and CSO Housing retrofitting differ substantially everywhere, occupying a different market segment and having a different market potential. Similarly, the institutional and legislative background of different European Member states, as well as the residential values and economic possibilities, the availability of land and its price, up to the attitude of public authorities strongly influence the market potential of CSO Housing development. Based on a set of key determinants the following paper plans to map out and show the market potential of different CSO Housing projects in some European countries. The paper furthermore identifies opportunities for new business to be developed, and strategies for market players to come up with new and smart CSO Housing solutions.
This paper draws the attention of the structural designers and architects to the importance of employing the environmental data in all design and construction stages of buildings. The paper dispelled the fact that final design of buildings cannot be performed ignoring the environmental data, especially in the hot-dry tropical regions. In that respect, the paper focused on the introduction of the solar radiation values that are received by the buildings during the day into the selection of most suitable construction material, as well as the design of thermal insulation thickness for walls and roofs of buildings at Khartoum State in Sudan. The paper assumed the walls and roof are the media of heat exchange between the internal space and the climate, excluding the building floors. The traditional heat transfer equations were used for estimating the main values of thermal conductivity at the level of the building and not the region. The paper also minded the financial situation of the owners and assumed three thermal levels for a building in the study area at Khartoum State. Inside and outside temperature measurements on a study building, which is insulted using thermal level three, are presented. The results showed that the thermal design of concrete sections qualifies it for operation with high efficiency by reducing the primary and secondary loads. Moreover, it raises the lifetime of the building and avoids the phenomenon of creep. On the other hand, the paper concluded that: reduction in the solar radiation by 20% to 40% will reduce the building thermal operational cost by same percentage. Also the paper puts preliminary steps towards establishing measures to assess the thermal performance of any building according to: Thermal conductivity, solar radiation and latitude. Emphases for interaction and integration of the role of architect, civil, material, and air-conditioning engineers must start in the early stages of building projects specially at the hot-dry regions.
As a way to minimize the waste of materials, time and effort to generate the maximum value, the lean construction concept has been introduced successfully into the construction industry. This paper first examines the implementation of the lean construction principles, which is primarily focusing on waste reduction. The paper then suggests the adoption of a process-based approach to integrate the lean principles into the off-site prefabricated housing production. A case study on Hong Kong public housing production is presented in this paper. The study analyses the detailed business process along the supply chain of public housing production, which typically includes the design, manufacturing of prefabricated components, cross-border logistics, as well as on-site assembly and operation. Observations are made on the existing procedural deficiencies from the perspective of the client In order to further improve the efficiency and increase the cooperation among various supply chain actors, information communication technologies are implemented by the client based on the process-based approach.
The hygroscopic capacity of timber can significantly improve the indoor conditions in log houses. Relative humidity of indoor air is, along with air and surface temperatures, a key factor for thermal comfort and also for perceived indoor air quality. The ability of timber to store moisture during indoor load periods and to release it back to the indoor air during unoccupied periods makes it possible to smooth down the indoor relative humidity variations by passive, structural means. This paper presents the numerical simulations carried out to study the effect of this moisture buffering effect in log houses compared to houses without available hygroscopic material. The numerical simulations were done using a room space model that integrates the structures, indoor air, and the ventilation, heating and cooling systems. The model solves the indoor temperature and humidity values using these dynamically changing heat and moisture flows. The analysis was done for Northern climate conditions (Helsinki, Finland) and the indoor loads corresponded to a case with two persons sleeping in one room. The ventilation was set constant (air change rate 0.65 1/h) and the room occupation and load conditions were repeated every night over the one-year simulation period. The results showed that when the room had four log walls, the moisture transfer between indoor air and walls was significantly higher than the moisture transport caused by ventilation. In the case with four log walls, the yearly average relative indoor humidity during occupation was 42 % RH and the maximum 69 % RH, while in the case with non- hygroscopic structures the average indoor humidity value was 51% RH and the maximum 93 % RH. The maximum level for indoor comfort is typically 60 % RH. In a case with non- hygroscopic walls, the indoor humidity exceeded this limit value in about 20 % of the yearly occupation time, while in the log house it was about 10 % due to the moisture interaction of the walls. Also the lowest humidity levels during cold winter period were higher in the log house when compared to non-hygroscopic walls. Utilization of the moisture capacity of structures to smooth down the indoor humidity conditions offers an effective passive method to improve the indoor air conditions in an energy efficient and sustainable way. The effect can be easily applied in log houses that have high hygroscopic capacity. This paper presents the potentials and sensitivity analysis of this application.
The refurbishment, conversion or upgrading of existing buildings always involves energy-efficiency issues. Upgrading a building to improve its energy efficiency requires careful consideration if works are to be effective, economical and avoid damaging the historic character of the building. The selection in applying measures result from the level of building conservation and the building condition. The basic subject of this research is the existing housing stock presented through residential buildings in the central part of Zagreb from the period prior to 1940. The year of construction of buildings (1870-1940) provide a general idea about the method of construction and the materials that were used, and these are the factors influencing the building’s energy performance. They are two and three-story buildings of massive brick walls without thermal insulation and single-glazed double windows, with unheated basements and attics, with vaulted and wooden ceilings and with gable roofs. The street facades are rendered with ornamentation. The research will analyze energy performance of buildings of this period and demonstrate energy-efficiency upgrade measures in terms of their constructional details and energy performance benefits. This paper will show the importance for integrated approach balancing between energy efficiency and protection requirements. The concepts range from a simple energy-efficiency improvement for a building envelope to more complex and expensive methods such as extensions and even demolition work. Possible constructional measures include improving the thermal insulation, renewing the windows, eliminating thermal bridges or decreasing the solar heat gains by providing sunshades. For buildings protected by conservation orders, it is clear that non-intrusive upgrading can ensure that a traditional building has the potential to the long-term viability.
