Commencing works on a construction site, regardless of the vision and size of the planned project, should be preceded by a series of activities aimed at optimising the subsequent process of its creation. Applying the right weight to a professionally prepared estimate is key to minimising the risk of investment shutdown at a later stage of the project, for example due to underestimating the construction costs. There are legal regulations describing in detail the requirements for cost estimates, but they only apply to the public procurement sector. Nevertheless, investors operating in every market segment should make sure they have a professionally prepared cost estimate for a building. Disregarding this aspect may seem like saving time and money at first, but in the long term it can have serious consequences for the profitability of the investment.