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.

Not only in Austria but also in EU and worldwide is the problem concerning restoration of old buildings very present. In the soaked massive brick walls are very often, moist caused, low thermal resistance and very low surface temperature, especially in the walls corner. At the Research Centre of Building Physics, TU Vienna, was an investigation carried out, which should act solution to this problem. To compensate thermal deficits of a cold wall corner (thermal bridge) area a linear heating component has been studied in the form of a pipe-in-pipe system, which raises the temperature of the wall corner and prevents the condensation. Through a targeted local heat supply, the necessary heating power is registered, within the temperature doesn’t fall below the critical value, at which it can come to building of condense water or to formation of mould. The calculations performed with a COMSOL program were carried out using tests on a real object. Thus, the calculated and the measured values could be compared. The first results can be seen as promising in terms of heating power saving, where you don’t need to heat the whole room to a high temperature. Through the selective heat power supply in the corner area thermal bridge effect will be eliminated.

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.

There has been increased effort for achieving enhanced properties of brickwork for external cladding of buildings, in particular as regards thermal insulation. This trend is caused by various factors, while the most important one is general aiming at reduction of energetic demand of buildings (within EU connected with the Regulation of the European Parliament and of the Council 2010/31/EU) and aiming at reduction of energetic demand of production of construction materials and building structures. The price of the products themselves is also important, because it determines their competitive strength in the market. One of the ways of development of thermal insulation brickwork with enhanced end-used properties with low price and minimal demands for material resources is use of secondary raw materials with low value of thermal conductivity. The paper describes possibilities of using granulated PUR material manufactured from water PUR foam used for production of thermal insulation form-pieces with integrated insulation layer.