The bulk of people who want to build a house are unlikely to represent the whole depth and seriousness of the plan, and even more so, does not suspect what specific actions will have to be performed at each stage of construction. Even the very first step is not everyone can correctly determine. Meanwhile, the first business is the creation and approval of the construction project, which will be followed by other, no less important stages. For example, installation and design of ventilation, which not everyone can master on their own, because for this you need to either be “in the topic” or trust specialists. Otherwise, you can break large firewood with a loss of considerable means. In addition, such an area as ventilation should comply with the necessary standards and technical requirements that will be reflected in the documentation. The design stage is very important, and it is on it that all issues of the planning and arrangement of the necessary and strategically important points should be resolved.