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  • Lorianna Kastrop

The Impact of 3D Drafting on Estimated Architectural Fees

By Lorianna Kastrop, Vice President, The Kastrop Group, Inc. Architects

To most folks who work outside of the construction industry, understanding architectural fee estimates is a mystery. It’s not like going to a car mechanic and getting an estimate. The mechanic knows the make & model of the car, its track record for maintenance, detailed manufacturer specifications, the cost and availability of parts, as well as the amount of labor required for repair or replacement, based on thousands of identical cars. After adding his/her overhead, your car mechanic can give you a pretty accurate estimate for the work you need done.

Your building, however, is unique. Your location is unique. Your desired scope of work is unique. There is no preexisting mathematical model that we can plug your project into. In this article I will attempt to demystify the estimating process and how it is changing due to the use of newer and more powerful design software.

Here is a simplified example to explain the process. In our firm the most basic steps for a project are these:

  1. We start by assessing the Existing Conditions (EC) of the property and the building. We will give you an estimated fee for creating the necessary base drawings of the existing conditions and for our customized Schematic preliminary Design (SD) based on your wants and needs.

  2. After we complete the SD, we can get a ballpark Preliminary Construction Estimate (PCE) to determine if the initial design concept is within your budget. If not, we will revise the design.

  3. Once you approve the SD we will give you an estimated fee for the next steps. The next steps are to refine the design in the Design Development (DD) phase and put together the plans and specifications into a Construction Document (CD) set that can be submitted for permits.

For a standard project you will receive a minimum of two estimates from us. Using our acronyms, they are EC/SD and DD/CD. How do we know in advance how much time it will take to provide the architectural services for your individual project on your unique building? The truth is we don’t really know for certain. We are making a prediction. It’s an estimate, not a definitive price.

Now let’s go through a simplified version of the estimating process. When we prepare a proposal, we first carefully evaluate the “scope of work” that needs to be accomplished. We can make an educated guess on the time it will take, based on our experience with similar projects. We factor in what is typically required in the jurisdiction where the building is located. We know the current state building code requirements and assess whether we can utilize specifications, details, and design elements from our firm’s library that we have used before. Then we add time for the scope of work that we know will be prepared especially for you and your building, and the complexity of the project. When we have the PCE from a reliable licensed contractor, we can use that as a double check. We know the range that architectural fees fall into as a percentage of construction cost for various kinds of projects. Sometimes we can reduce time if we have worked with the General Contractor before and know their expectations for the construction documents. There are other factors, but these give you the basic idea. Taking all of these things into consideration, and a contingency percentage for any unforeseen issues that could crop up, we will give you an estimated fee that we believe is fair and reasonable.

In the past, the Existing Condition and Schematic Design (EC/SD) estimate, generally speaking, was about one-third of our overall fee on a project. The Design Development and Construction Documents (DD/CD), tended to be about two-thirds of the total fee. This was due to the amount of time and drafting necessary to take design sketches and turn them into complete construction documents. We told people to try to make their changes or revise the design in the schematic design phase, because it gets expensive when we have to change the construction documents later in the process.

Now that we commonly use 3-dimensional (3D) architectural software on many projects, our estimating process is changing. (Standard CAD software is still faster and less expensive for some projects that don’t really need any 3D analysis or perspectives.) We are finding that on the 3D projects we make a lot more design decisions and do a lot more data input and drafting early in the process.

One benefit of the 3D architectural software is that it is much easier to make changes or refinements later in the process.  Being modeled in 3 dimensions, the design changes are automatically implemented throughout all the 2D drawings (plans, elevations, sections).  They are directly linked to the ‘smart’ 3D model, so there is no chasing down the changes in each of them individually.  It is also faster to complete the DD/CD phases, because of all the extra information being acquired early on in the EC/SD phase because of this modeled third dimension.  We are now using a rule of thumb for 3D projects that the estimate for EC/SD will be about half of the total architectural fee and the DD/CD estimate will be the other half.  The total fees would be the same, but there is more labor involved in the initial phases of the project.  (Time for Construction Administration and observation of the project under construction can vary too widely to be estimated in advance.)

Why is it helpful to know about the estimating process? We hope that this explanation will help potential clients on a 3D architectural project avoid sticker shock when you get the estimate for the EC/SD phase of your project. It will be offset by a lower price for the DD/CD phase. You will gain increased flexibility for making changes to the design. And, of course, you will benefit from the improved visuals on the drawing set to help in the decision-making process to finalize the design. There are new and powerful digital tools available to architects, and it makes sense to change our way of doing business to utilize those tools. For more information on Design Phases, and to download our free digital booklet “Architectural Projects: A Step-by-Step Guide” visit our website at and click on “Design Phases” from the “Resources” tab.

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