Visual Impact

Visual Impact
Posted by on December 11, 2013
Posted in: construction, legal, photomatch, projects, transportation

For the second time in as many years, I’ve been asked to testify as an expert witness in a condemnation trial. Thankfully, no one is being sentenced to death. In this case, condemnation refers to Eminent Domain, the power of a government agency to compel private property owners to sell land or easements that are required to complete a project that is “in the public interest.”

The public project in this case is an expansion of airport light rail service. A nearby hotel owner received notice that an elevated track structure will skirt one end of his property, coming as close as four feet from the hotel building. This will likely result in some lost customers and have a negative impact on property value. The question is: how much value will be lost? Is it possible to determine the impact of something that isn’t yet built?

The jury heard testimony from competing appraisal experts, including lots of numbers and unfamiliar acronyms. This is important quantitative information. However, it’s often the qualitative information that leaves a lasting impression. In this case, it was vital to put the jury in the shoes of potential hotel guests by showing them “before-and-after” pictures from two key locations on the hotel property: the entrance, and a room facing the new tracks.

Using a digital model and photos taken from the site, we created these photo simulations:

Digital model / aerial view

View of hotel rooms closest to elevated tracks

Detail of gap between building and elevated rail structure

BEFORE: View from hotel room

Visual Impact

BEFORE: Hotel entrance

AFTER: Hotel entrance

The procedure for any visual impact study should include three important steps:

  1. Photograph existing site conditions. Choose several key locations that are vantage points for people affected by the proposed structure.
  2. Use a normal lens for these “before” photos. Using a 35mm equivalent focal length of about 50mm results in a field of view that is similar to human vision, which means the objects in the photo will not appear unrealistically close or distant.
  3. Identify several reference points. These objects (such as a utility pole or building corner) are used to calibrate the digital model. Reference points make it possible to confirm that the perspective of the virtual camera matches the perspective of the real camera.

In addition to the Elevated Train case discussed above, we’ve done visual impact studies for other projects including a highway wall (first two images below) and solar array installation (last three images below).

Here are some samples from those projects:

View from property #1 at beginning of construction.

Simulated photo of completed structure from same perspective

Site of proposed solar array before installation.

1.75 MW installation: photomatch rendering

Photograph of completed installation

Visual impact studies can be powerful evidence when arguing for (or against) a new project. Be sure to follow the steps outlined above to ensure that your future photos are as accurate as possible.

About Joshua

Joshua Cohen founded Fat Pencil Studio in 2004. Read more