Abstract An action have cities worldwide, due to urbanization. More than 70 percent of people in Europe live in cities, where 70 percent of the energy consumed. Without adequate measures, a rapidly growing city is at risk in by overloading the infrastructure, threats to water, energy, pollution, logistical bottlenecks and lack of housing. This paper describes an energy-efficient renovation or expansion planning a real estate in Vorarlberg, Austria. The settlement was analysed in more detail here, it involves the city Dornbirn- part Shor. The study investigated how to extend this settlement energy efficient and what feed for factors in the assessment.

The building sector is responsible for 40% of the current CO 2 emissions as well as energy consumption. Sustainability and energy efficiency of buildings are currently being evaluated, not only based on thermal insulation qualities and energy demands, but also based on primary energy demand, CO 2 reductions and the ecological properties of the materials used. Therefore, in order to make buildings as sustainable as possible, it is crucial to maximize the use of ecological materials. This study explores alternative usage of sheep wool as a construction material beyond its traditional application in the textile industry. Another goal of this research was to study the feasibility of replacement of commonly used thermal insulations with natural and renewable materials which have better environmental and primary energy values. Building physics, energy and environmental characteristics were evaluated and compared based on hygrothermal simulation and ecological balance methods. The observations demonstrate that sheep wool, compared with mineral wool and calcium silicate, provides comparable thermal insulation characteristics, and in some applications even reveals better performance.

Due to an increasing request for ecological building constructions, in particular straw bale buildings, a research in this regard has been performed at the Vienna University of Technology. Straw bale construction is a new rediscovered building technology, which is an alternative to conventional construction technologies. The aim of this study is caring out of hygro-thermal simulation of a straw bale wall construction to design as efficiently as possible straw bale house. The choose of other construction elements for a thermal analysis (appropriate wall, roof and a base plate construction), was based on an extensive literature researche. For the examination of the building a timber frame construction has been selected. The straw bales in this construction were plastered inside with clay plaster and externally with a combination of lime and clay plaster. The roof structure was designed as a green roof and insulated with straw bales. The base plate was also insulated with straw bales. To check the thermal behavior of the structures described above were thermal bridges calculated using a FEM program. The hygrothermal behavior was calculated with HAM4D building physic software, developed on the department for Buildings Physics and Sound Protection on Vienna University of Technology. Ecological and economic evaluation of straw bale construction was carried out with reference to the data from the literature. The performed thermal (with COMSOL) and the first hygrothermal calculations (with HAM4D Software) have demonstrated a very favorable performance of the proposed building components. The achieved low U-values of the components allow the construction of passive houses. The use of self-build-service in the construction process can reduce construction costs significantly. The use of ecological materials such as: straw, clay and wood allows a low cost recycling of building materials.

The development of non-traditional, thermal insulation plaster leads to the development of new eco-efficient materials suitable for insulation and rehabilitation of both existing and new building structures. Optimal function of these materials is then to reduce the energy consumption of buildings. This is beneficial from an environmental perspective. In addition, the development of new, promising, thermal insulation plaster was used innovative, environmentally friendly binders, such as substitution for energy intensive binder - cement. The paper presents the results of development of thermal insulation plaster and research in their hygrothermal behaviour.

Natural fibre based thermal insulating materials belong to progressive building materials representing one of the possible ways in sustainable development and which are characterised with low carbon trace and low value of primary bound energy. In case of industrially produced insulating materials (for instance using thermal connection method) the insulating materials based on natural fibres showed comparable properties with industrially produced insulating materials on building markets. In the view of thermal insulating properties the natural insulating material show slightly different behaviour in comparison with synthetic insulating materials which is caused by fibrous structure of insulating materials and low thermal conductivity of natural fibres (contrary to glass or mineral fibres). The paper describes results of research oriented on study of heat propagation within materials based on natural fibres originated from agriculture and stockbreeding.

The development of prospective, thermal insulating plasters that are applied during the reconstruction and rehabilitation of structures has taken place at the Faculty of Civil Engineering for many years. The main objective of the research work is to achieve the best ratio of thermal and mechanical properties, including high porosity. During the development of this test, testing recipes were tested, which were often used as alternative input materials. On the basis of the achieved results, optimal recipes were proposed with the stated requirements for heat insulation, mechanical properties and porosity. Due to the fact that during the reconstruction this often concerns structures loaded by increased structure, then such materials must have high open porosity. The article describes the study of moisture behaviour, particularly capillary activity for light thermal insulating plasters with the use of alternative raw material sources.