A major reason to work with a BIM (Building Information Modeling) architect is to see more design alternatives. We have been using our Revit platform to accomplish just that.
Typical architecture design contracts used to always limit the number of conceptual designs an architect would show a client. Cost drove this limitation. While schematic design is about one-sixth the effort of a typical architecture project, producing twice the number of schemes meant spending 15 percent more than the architect signed up to do. 15 percent is the profit target for a lot of design firms. Therefore, providing several schematic designs could easily wipe away the profitability of a project. I remember a few years ago a client complained about a project done by another firm. That architect provided two conceptual designs and asked the client to choose between the two. Neither option fit, but one was the lesser evil. The client went with that one and regretted it.
The feedback we receive when we show three, four or more options has been overwhelmingly positive.
Why are architects hesitant to show several design options? Again, it comes down to cost. It may take a designer (the person working with trace paper and a Sharpie) three hours to come up with the basic idea for a design option. I am thinking about projects that might cost $1 Million. For this size project, the architecture fee (not including engineering design such as mechanical, electrical and structural) might be $50,000. The schematic design phase might be $7,500 (15% of the architecture fee). A designer’s billing rate might be $125 per hour. In round numbers, a design option incrementally costs $500. It seems a firm could fit at least three or four design options into a schematic design fee.
The problem lies with the amount of effort traditionally required to document a conceptual design. Three hours may pass between the time a designer starts exploring options to the time when the light bulb goes off in the designer’s mind. Another 20 hours may pass as the designer works with drafters to flesh out the insight into understandable and defensible images. Each design option is not a $500 exercise. It is really a $2,000 exercise. And with a $7,500 schematic design budget, each exercise is almost a quarter of the available fee. After the programming and project start-up work has been done, there are not a lot of $2,000 piles of cash left to burn.
BIM has changed all that. Revit has a neat feature that allows a single software file (the Project.rvt file) to be partitioned into several sandboxes. Each sandbox is an area that can contain the geometry and annotation necessary to describe a design option. In fact, Revit calls these sandboxes ‘Design Options’. For a recent renovation and addition project, we created six design options. The options were based on underlying geometry that modeled the existing building. Some options were similar to others. Some were not. The average time invested in each option was about four hours: one or two hours to think up the option, and then one or two hours to produce the documentation.
The feedback we receive when we show three, four or more options has been overwhelmingly positive. Clients understand we have explored more than one or two possibilities. They also begin to see how four basic ideas might be combined in 16 different ways. “Leave no stone unturned” has a nice ring to it when you want to show that you have considered everything.