Building construction based on ecological, locally available, and slightly processed materials have a positive effect on the environment and local economy. Due to its simplicity, and thus possibility to erect a building on one’s own and using inexpensive materials, it may potentially become a solution to satisfy the continuously growing demand for residential buildings. In the paper, three variants of ecological external walls were proposed: a wall made of clay blocks insulated with mineral wool boards; a wall made of clay compacted in formwork insulated with mineral wool boards; and a wooden frame structure filled with straw bales and cladded with fiberboards. The layers of the walls were chosen in such a manner that the heat transfer coefficient values for the studied variants are as equal as possible (0.2 W/m2K), thus allowing for a reliable comparative study. The cost calculation of each variant of walls construction was made. The obtained results allow selection of a more advantageous solution.
