THREE MUST-HAVES BEFORE BEGINNING SITE DESIGN
Have you ever heard the saying “Garbage in, garbage out”? It references that if you start with inadequate information (garbage), you’ll produce a lower quality product (garbage). For developers, “garbage” can mean incorrect or incomplete information. If you start a site design without committing the resources/funds needed to fully understand the site, you’re asking for problems to arise during construction which could lead to increased construction costs. Eliminating the “garbage” of inaccurate and incomplete site information means a project of higher quality with less surprises and resulting change orders down the road. Below are three things I recommend doing before starting site design on any project to ensure all parties have the information needed to reduce headaches in future phases.
Get an updated survey. When buying a property, the current owner may offer you the survey they completed when they purchased the property years ago. This seems helpful and is valuable information not to be discounted. But sometimes clients want to use these existing surveys to save the time and additional expense of having it updated, possibly doing “spot checks” at only a few locations. However, from these few spot checks it is difficult, if not impossible, to know the quality of that existing survey. That’s a gamble that can cost the developer and development time and money later in the project.
For example, early in my career, a client did not get an updated survey because it would cost $60-70,000 on 40 acres. During construction, it was discovered there were areas of the site where the ground was higher and trees were larger than assumed. This caused many issues resulting in larger retaining walls and even changing a sidewalk/flatwork to a deck to accommodate trees that were five feet below grade rather than at grade per the original survey. I’m sure the client wished he’d spent the additional time and money up front to avoid these headaches and the increased cost.
Get a Phase I Environmental Assessment. This assessment is another way to limit your risk for future surprises by evaluating the environmental conditions on your client’s site. Imagine a piece of property was once a farm or a car repair shop. Any liquids or hard chemicals used on the site can cause contamination, even many years later. If you purchase the property and then learn it contains hazardous contaminants, you as the owner are now responsible for the very costly environmental cleanup. If you do find contaminants on the property, it is recommended to either discuss with the seller so they can remedy or drop the sales contract. It can take years to clean contaminants from a site, which is not a situation most developers want to be in.
Consult a Geotechnical Engineer. Obtain a geotechnical engineer’s opinion to ensure you understand the soil makeup of your site. Again, this is about limiting surprises than incur unforeseen expense and time. You may not even need a complete report and can simply have a consultation with a geotechnical engineer.
What kinds of problems can soil present? You’d be surprised! Most of western Austin topography is composed of limestone beneath 1-2 feet of soil. Buildings built here aren’t likely to move. However, the east side of Austin contains areas of clays, some of which are very expansive clay. In some instances, if you were to remove 10 feet of soil for construction, the expansive soil underneath is now exposed and, you guessed it, expands. It can even expand close to the original elevation, causing issues with your foundation, building entrances, egress, etc. In the past, I have received a geotechnical engineer’s recommendation to not begin construction for a long period of time to allow the newly exposed soil to expand, as well as the use of a building foundation with voids to prevent soil from affecting the foundation’s elevation.
Each tip I’ve mentioned is a part of conducting a thorough due diligence process before site design begins. It requires extra time and cost up front, but it’s a smart investment to minimize the risk of surprises during construction. There’s a reason experienced developers always want these items in the scope of work – they’ve seen what a headache it can be when a project begins with inaccurate information!
About Vince Musat
Vincent D. Musat, PE, LEED AP, is the Division Director for Foresite Group’s Land Development team in Austin, TX. Vince graduated from the University of Houston with a degree in Architecture and from Texas A&M University with a degree in Civil Engineering. Vince has over 24 years of combined experience in Civil Engineering, Architecture, and Land Development, and he enjoys using his creative and technical skills to emphasize the aesthetic qualities of a project’s environment, while also maintaining a practical and budgetary approach to the design.