Why Engineering is Vital Even When Not Required

You’re planning a home renovation or a new build, and you’ve been told by a building official that a structural engineer’s stamp isn’t required for your project. On the surface, this might sound like a simple way to save time and money. However, at Blue Sky Engineering, we know that a project being “engineering-exempt” is not the same as being “risk-exempt.” The reality is, you have two primary methods for building a structure: the prescriptive method and the engineered method.

While we respect and work closely with building officials, relying on the prescriptive method alone can be a costly and even dangerous miscalculation. A structural engineer provides a layer of safety, precision, and long-term value that is essential, regardless of a city’s specific permit requirements.

The Prescriptive Path: Simple, But with Critical Blind Spots

The prescriptive method of building is a set of pre-approved guidelines and tables found within the building code. It’s a “recipe-book” approach to construction, dictating standard sizing and spacing for common materials (e.g., a 2×10 floor joist for a certain span). This method works well for very basic, cookie-cutter structures in ideal conditions.

However, the prescriptive path comes with critical blind spots. It simply does not account for a wide range of real-world conditions that are common in Utah and beyond, including:

• Unique Floor Plans: Many popular designs, such as ‘L’ or ‘U’ shaped homes, or those with angled walls, do not qualify for the prescriptive method. These plans necessitate a specific, engineered approach from the very beginning to ensure compliance with the building code.
• Unique Framing Details: The moment a design includes a large window opening, a complicated roofline, or an open floor plan, the prescriptive method is no longer valid.
• Heavy Wind Loads: While prescriptive tables cover basic wind zones, they often don’t account for the high wind speeds common in canyon mouths or open plains.
• Specific Seismic Forces: The prescriptive method provides only the most basic seismic design guidelines. It does not perform the detailed calculations needed to ensure a building can withstand the specific seismic forces of a region like the Wasatch Front.

In short, the prescriptive path is a simplified solution for a simplified world—a world that does not exist in the reality of most construction projects.

The Engineered Approach: A Custom-Fit Solution for True Safety

Assess Local Environmental Loads: We perform precise calculations for wind load, snow load, and seismic forces based on your exact location, ensuring the building is designed to resist every element it will face.

Consider the invisible forces your home endures, like a seismic event. This is where shear walls and hold-downs become your home’s unsung heroes. The prescriptive method provides only the most basic guidance for these elements, but a licensed engineer understands that shear wall science is a cornerstone of modern seismic design. We design the precise size and placement of these shear walls and their critical hold-downs, ensuring your home can resist the lateral forces that can cause a building to rack and twist off its foundation. This is a level of site-specific analysis that no generic, prescriptive plan can provide.

Design for Uniqueness: The moment a design includes a large window opening, a complicated roofline, or an open floor plan, the prescriptive method is no longer valid. We provide the precise structural design that a prescriptive plan cannot.

Ensure Long-Term Durability: Our work accounts for the long-term effects of aging and wear. A professionally engineered plan considers how materials will perform over time, ensuring your home is not just safe on day one but for decades to come.

Optimize for Cost and Efficiency: An engineer provides a design that is both safe and cost-effective. We prevent over-building, which wastes materials, and under-building, which risks failure.

Protecting Your Investment with Engineering

The myth that a single-story home doesn’t need engineering doesn’t pass the common-sense test when you consider the investment spent on a home. A building official’s approval is simply a license to build; a professionally engineered plan brings quality and safety into focus and its value shouldn’t be overlooked.