Specialist design and construction preparation

Specialist design refers to technical planning, such as structural and building services design. Specialist designers must hold qualification certificates corresponding to the complexity category of the project. Some specialist design work can be completed after the actual building permit has been granted, provided it is done no later than before the start of the relevant construction phase.

For prefabricated house packages, most specialist designs are provided by the house supplier. However, designs related to foundations and ground structures, as well as any potential retaining structures for the yard, are always designed on a site-specific basis. Before commencing construction and, for example, ordering house packages, the builder should commission a soil survey (ground investigation, site levelling, and a foundation method statement) and a landscaping plan for the plot.

Moisture management is ensured through a moisture management report. You can prepare the moisture management report in cooperation with designers, supervisors, or the house package supplier. The report includes moisture management requirements for different stages of the project, and a responsible person is appointed to oversee moisture management.

Statutory duties of specialist designers

The designer of load-bearing structures is often referred to as the structural designer.

The base structure designer is responsible for the design of the site’s ground structures.

In detached house projects, the structural designer often also acts as the base structure designer. A base structure designer must always be appointed to the project regardless of the ground/soil survey. Please consider this in your commission agreements.

The building physics designer is responsible for designing the moisture-technical functionality of the site.

In small house projects, the structural designer usually also acts as the building physics designer for the site.

The HPAC designer is responsible for the design of the building’s heating, water, and ventilation systems. For small houses, HPAC design also includes water and sewerage design. This entity is often also referred to as building services design.

The ventilation design requirement also applies to natural (gravity) ventilation.

Construction preparation and site plan

Before commencing building work, the prerequisites for starting construction must be met: completed specialist designs, responsible persons, a site plan, and the conditions mentioned in the building permit.

Consider construction preparation in your schedule. If you have not completed the tasks for this phase before the building permit is granted, it is advisable to reserve 3 months for construction preparation.

Before construction, the principal designer and the person engaging in the building project must ensure that the necessary specialist designs are completed and that specialist designers are named in the Lupapiste service by this stage at the latest. The specialist designer in question and the principal designer are jointly responsible for the quantity and quality of the specialist designs.

Brief the responsible site manager well on your project and follow their instructions. Facilitate the fulfilment of the responsible site manager’s duties throughout the entire building project.

The person engaging in the building project must, together with the responsible site manager, prepare a site plan with appendices. In the case of house packages, also discuss with the supplier which site plans you can obtain through them. The site plan is updated as the building project progresses.

A site plan for small houses usually includes at least the following areas:

• schedules
• moisture management
• site traffic and management
• lifting points and the safe placement of machinery, cranes, and equipment
• unloading of building materials and placement of storage areas
• site order and cleanliness, skips, waste sorting, etc.
• number and location of welfare and storage facilities
• fire protection
• quality plan
• possible construction or excavation on the side of adjacent plots
• site signboard

Occupational safety risks are considered during the construction preparation phase. The person engaging in the building project must appoint a safety coordinator for the project, whose task is to ensure that occupational safety is considered during the design and preparation phases, and to ensure that safety plans for the implementation phase have been made for the site and that a prior notice of the commencement of work has been submitted to the occupational safety and health authority.