The development of our civilisation goes hand in hand with deteriorating the environment. Mainly the natural resources are being depleted; in addition, there is the economic crisis, and all these factors increase the demand for economical buildings. Although the current boom in building industry provides a plethora of man-made materials, people feel the urge to blend in nature more and more. They want to create their own safe or ecological “warm nest”, which would be as environment friendly as possible and which would incorporate as many natural materials as possible. Houses from natural materials, in addition, passive and low energy, reducing the CO2 emissions can be built from straw bales. The Master thesis consists of theoretical and practical part. The aim of the theoretical part is to provide the analysis of material options for passive and low energy wood frame structures using natural materials, in our case – straw bales. The theoretical part deals with the analysis of straw bale houses. In addition, it also points at the fire resistance of their load-bearing structures according to the results of available fire rating tests from abroad. The subsequent part provides a design of material composition of a load-bearing straw bale wall with self-help construction of a wood frame building. The practical goal of the Master thesis was to find out the ability of the representative specimen of the load-bearing wall from straw bale to resist the effect of internal fire while maintaining its load-bearing capacity, stability, and integrity. Modelling programme ANSYS, used in practice for simulating the effects of fire on building structures, was used to study the selected properties of the designed load-bearing wall. While simulating in the programme ANSYS, the designed straw bale wall composition was loaded and subsequently the simulation of internal fully developed fire was monitored. Furthermore, the development of the temperatures in various parts of the straw bale wall composition and reaching the flashpoint temperatures of some materials in the wall composition was monitored. The wall resisted during the entire simulation time. This simulation process shows that the load-bearing structure from straw bales meets the requirements for the V rating of the fire safety of buildings being over 120 minutes.