Building materials and materials used in the household have changed greatly within last 60 years. Man has always strived for a comfortable, easy-going life which has resulted in new materials in construction and household that have enabled us to have just such a way of life. Homes have become more and more energy efficient and the fire load on the premises is higher. By comparing fires in a modern fire environment in relation to fires trough past decades, we can say that fire behaves the same as before, the physics and chemistry of fire remained the same, but the environment and sections in which the fire occurs have changed significantly changing the dynamics of fire. The basic mechanisms of fire spread have increased solely due to the products found in our environment. Following the above, the behavior of the fire has changed and the time needed for timely intervention decreased. In this paper, the differences in materials in use in the last 60 years will be described and how the modernization of materials in construction and household poses a fire hazard as well as an additional danger to the firefighter.