The diploma thesis deals with the cost determination of the family house reconstruction, which was built at the beginning of the last century and has already undergone one reconstruction in the 90s of the last century and the assessment of the building's valulation by the building modifications. The construction technical state of the house before reconstruction and description of the construction works and used technologies in the reconstruction realized in 20132015 are detaily described as well. Expected construction costs are determined by an item budget and actual reconstruction costs which were largely self-made are determined according to the tax documents of building owner. The determination of value change by house reconstruction was evaluated using the cost and comparation method.