The aim of this Bachelor’s thesis was to examine and develop cost control as part of designing. The purpose was to study cost control as a whole in detail and to discuss cost control including the total costs of the whole projects and the planning process.

Cost control is an integral part of designing. Everything influences everything. Designing is based on contracts and the task descriptions defined in them. Furthermore, the effects of various contract forms on project pricing and the designer selections and upgraded qualifications were discussed in the thesis. The costs are also affected by different regulations, circum-stances and especially the basis of design. The thesis presents a model where the budget would be an obligatory basis for designing compared to the normal situation of updating cost estimates as a process advancing from plans.

As a result of the thesis various practical methods were created. The mod-els contain examples to visualize the objectives of models. Co-operation methods, the significance of communication and the various procedures in the organization are paid attention to in the models. In addition, models contain a contract template which supports achieving the owner’s goals in designing as well as possible. Models also pay attention to the quality of plans, risk analysis, dividing of responsibility and consistency of plans as part of cost control. The thesis emphasizes the costs as a whole by clarifying the goal setting and through it to control the formation of costs comprehensively in the interest of the client.