The four stages

01. Discussion

Needs assessment, site, budget. At the end you know what can be built and roughly for how much. Needs assessment.

02. Concept

Sketch design and structural principle. This is where the cheapest route to the wanted form is decided — and where most of the later cost is decided.

It is the cheapest moment to change anything: the span, the number of storeys, the position of the bracing and the opening layout all fix here. Concept design: where the cost is decided · Why the concept decides the cost.

03. Permit

Full permit documentation, with the disciplines’ input and the authority administration if you want it. The permit package.

If the project goes by simple notification, the package is different. The simple notification package.

04. Construction

Detailed design, BIM model, clash detection. Supervision and construction management as required. Detailed design and BIM · Design supervision and construction management.

What to know about the stages

They are not copies of one another

Information is created at every transition: from concept to permit, the demonstration of legal compliance; from there to detailed design, the structural design and the coordination between disciplines. Design stages.

Going back gets dearer

Changing a decision at concept is a conversation. At detailed design it is reworking several disciplines.

The permit binds

The content of the construction documentation may not depart from the final permit — and the designer is responsible for observing that. The content of the permit design.

If the structure will be prefabricated

The fourth stage has to close before manufacture. After that, change is not a design question but a material cost. Coordination between disciplines.

The point

Four stages, with less room to move at each. The second matters most: everything is still cheap there, and it decides what the rest will cost.