Unconventionally Framed

Top 6 Ways A Structural Engineer Adds Value to Your Residential Project

It’s a fact; residential structures are most commonly framed with wood. In the midwest, this has been worked into a very efficient process. Typically, the homeowner works with their architect, building designer, or builder to come up with the best floor plan. Then elevations, building sections, and 3D renderings are put together by the architect or building designer and this information is transmitted to the lumber supplier to design and fabricate the framing members. 

These are typically pre-engineered roof trusses and engineered floor joists or trusses. The foundation walls are then usually specified based on prescriptive design parameters provided in the International Residential Code (IRC). The lateral system is considered satisfactory by inspection. Many times, a structural engineer is not involved with these homes. But, when is the capacity of this efficient system exceeded?  

When is a structural engineer needed for a single-family home? In some areas of the country, the jurisdiction requires that a licensed structural engineer design and sign off on single-family homes. However, in central Iowa, this is not usually the case and we get brought onto a job based on the discretion of the builder. 

Many times, we are not required to be on a job. Yet, we do not want to be involved if all other parties have the design covered, as we don’t want to simply to check a requirement box. We want to add value to the project. This typically means finding solutions for complex challenges. You may be wondering — what are these challenges, exactly?

Here are a few examples of situations when a great structural engineer can add considerable value to your residential project:

Modern Style Architecture  

If a modern style is preferred, say, with masses jutting out from the main home structure, thin plates, and cantilevers, it is likely that steel will be required to accomplish these effects. While this creates a unique and interesting building, the design gets very complex. It’s not about simply designing individual elements, it’s also tracking these forces all the way through the building and down to the foundation, taking into account both lateral and gravity loading. We LOVE these kinds of projects — the fun, innovative ones that wouldn’t be possible without our assistance and collaboration with the design and construction team. We see this as a chance to bring immense value to a project.

Large Footprints 

If a home is over 3000 square feet with large clear spans, it is likely that conventional wood framing will not be sufficient and a more creative framing approach will be required. This is another great fit for enlisting a structural engineer to come up with creative solutions.

A Back Elevation Full of Windows 

Many times, homeowners want large open windows in the back elevation of their home. From a structural standpoint, this removes a large portion of lateral stability at the back of the structure. Thus, we frequently have to design steel frames around these windows to take the lateral (wind/seismic) load at this face of the building and in plane with this wall.

Offset Load Paths  

If load-bearing elements stack from one floor to the next, wood stud walls are usually sufficient. However, if these load-bearing elements do not stack, steel transfer beams are commonly required. These offsets can make creative space layouts and also create challenging load path transfer. We love this challenge!

Complex Building Site  

Some homes are built on excessively steep building sites. In these cases, it is very important to enlist the expertise of a geotechnical engineer and a structural engineer. The geotechnical engineer performs a soil investigation and provides site-specific design parameters to the structural engineer so that the structural engineer can design a customized foundation. 

Existing Home Renovation Work that Requires Load Bearing Wall Removal  

In a typical floor plan, wood beams (LVL’s) usually work for spans up to about 16-18 feet long. Beyond that, steel is typically required.

As structural engineers, we love to solve challenges but not every job requires our input.  However, if your project entails one of these atypical characteristics listed above, it may be time to enlist the help of a structural engineer. Together we can merge math and science into art.