Construction FAQ: How long does it take to develop planning permission into construction drawings?

This is a response to a recent query on our website; it’s something all clients ask us so we decided to share the response on our FAQ. The technical design process requires a mixture of design, procurement work, and coordination of information by the architect, and a lot of decisions by the client.

Drawing Work

If you’re talking about a domestic renovation or house extension project, we usually produce the actual technical design drawings over about a week for a small project with very typical construction, and as much as a month for a larger project with more detailed design. This estimate would be based on the assumption that our office had produced the planning drawings, and there was already a developed BIM model (3D drawing file) in our office for the project. For example, if you just bought a property with PP, and you didn’t have digital files, you could add a week for re-drafting a project on BIM from the paper drawings on the public file for planning purposes.

Procurement and Management Tasks

This is just an estimate of the drawing tasks, getting a project ready to build takes a lot of planning and management work. The architects’ technical design (for construction) happens at the same stage as other key tasks, which are actually much slower than producing the drawings:

1. Deciding on a strategy for finding a builder: negotiation, open tender process etc.
2. A lot of meetings to select the right team for you
3. Completing building control paperwork
4. Other technical design tasks by engineers or suppliers
5. Pricing of special elements of the design, such as feature windows or special appliances.

All of the above lead to technical decisions which must be added to the drawings and specifications, so while the construction drawings may look largely complete after a few days of work by the architects, important changes can filter through over a long period from the client, engineers or suppliers.

Clients Set the Pace

At technical design stage, clients usually take a lot of time to shop around for the best value, because this is when the budget is finalized for the project. It is also when the details are decided which determine the materiality and feel of the building. Clients quickly realize that time spent on the technical design can have a big impact, not only on value and quality, but on their personal relationship with the building.

This post was written in response to a general query, if you have a building with planning permission, please feel free to give us a call, this is very broad advice, and it may not apply to your situation.