This helps everyone in the design process understand where the project stands in relation to it's budget. If an unrealistic budget was set in the beginning, expect some major surprises. It's best to make any changes in a building's design before the start of construction documents. Once design development ends, it becomes very difficult to incorporate changes.

Think of it as going to a restaurant and ordering a meal. You place an order and the chefs start preparing the ingredients. While it's best to tell them ahead of time what you want, changing your mind in some restaurants is permissible as long as they haven't started cooking yet. Once all those ingredients are in the pan, you can be sure the restaurant will charge you for it. Adding or changing anything in that meal, as you can see will be difficult.

It's not impossible and a good chef can adjust for it. But since it's not in the menu, they will charge for the extras as well as the original meal. That analogy to a restaurant would be similar to an architect's extra services once changes are made after design development has been approved.

Construction Documents (CD)
Completion of design development (DD) means the begining of construction documents. These are where the details of how everything goes together is documented. Window and door penetrations, roof details etc. Depending on the type and complexity of the project, this normally drives the amount of documentation needed.

Some jurisdictions may require that a permit set of drawings be issued for review prior to construction. They will review the set for building code and structural requirments.

project delivery DD-CD administration