Last edited 10 Jun 2019

Design phase

In a traditional building contract, the design phase comprises two stages:

[edit] Concept design

An early phase of the design process, 'concept design' articulates the broad outlines of function and form, Concept design generally takes place after feasibility studies and options appraisals have been carried out and a project brief has been prepared. The concept design represents the design team's initial response to the project brief.

Some designers differentiate between 'concept design' and 'scheme design'. In this case, the 'concept' is the initial design idea, whereas the 'scheme' develops the concept, taking on board more functional and practical considerations. Most project plans have now combined these two steps into the single stage 'concept design', or 'concept'.

Concept design is followed by 'detailed design' or 'developed design' during which all the main components of the building and how they fit together are described.

During the concept design stage, the consultant team will develop:

At the end of the stage, the consultant team will prepare a concept design report for the client which records the basic design concepts for the preferred option that might be worth further investigation in the detailed design stage. The concept design report will also identify any instructions required from the client.
The project brief will continue to develop as the concept design is prepared, but is then frozen at the end of the concept design stage and change control procedures are introduced.

An application for planning permission might be made during the concept design stage. This is likely to be an outline planning application if made at the beginning of the stage or a detailed planning application if made once the concept design is complete.

The above serves as an outline. For a more detailed account see ‘Concept design’.

[edit] Detailed design

Sometimes referred to as ‘developed design’, detailed design adopts and develops the approved concept design.


By the end of the detailed design process, the design should be dimensionally correct and co-ordinated, describing all the main components of the building and how they fit together. However, technical aspects of the design may require further development, design by specialists may not yet have been fully incorporated into the design and it will not have been packaged for tender.

Detailed design should provide sufficient information for applications for statutory approval to be made.

Items that are typically included in detailed design include:

The above serves as an outline. For a more detailed account see ‘Detailed design stage in building design’.

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