Houston Permit Service News • April 4, 2025

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hen handling permits for residential or commercial projects in Houston, a common question arises: when does the City of Houston (COH) require a soils report? We recently explored this for a structure with a foundation depth of about 1 foot—think slab-on-grade homes, small warehouses, or light commercial builds—and here’s what we learned.

The Situation

Our team was working on a permit for a project with a shallow foundation, roughly 1 foot deep. A team member checked with COH and found that soils reports typically apply to deeper excavations—often starting at 5 feet or more—depending on the job. For shallow foundations, common across many structure types, the requirement usually doesn’t kick in unless the city flags a specific issue.

Digging into COH Rules:

The Houston Building Code (2015, Appendix J – Grading) governs excavation and grading: Section J104.5 states that a soils engineering report is needed for “engineered grading” (over 1,000 cubic yards) or when the building official deems it necessary due to stability risks. For “regular grading” (under 1,000 cubic yards) with shallow depths like 1 foot, it’s often waived unless special conditions—like flood hazards or unstable soil—apply.

The Infrastructure Design Manual (IDM, 2023 Edition, Chapter 9) reinforces this, focusing geotechnical requirements on deeper infrastructure (e.g., utilities or heavy foundations). Shallow foundations under 5 feet rarely trigger these rules unless the site’s in a Special Flood Hazard Area (per Chapter 19 of the City Code) or involves significant earth movement.

Houston’s soil—expansive clays, sandy patches—can complicate deeper digs, but at 1 foot, you’re typically above the trouble zones. Our coworker’s COH contact suggested 5 feet as a practical threshold, though it’s not explicitly codified for all cases.

Why It Matters

Skipping a soils report for shallow foundations saves time and cuts costs—key for projects like homes, small offices, or storage buildings. But it’s not a free pass: COH can still request one if your site’s tricky (e.g., near a floodplain or with odd soil). Knowing this helps us keep permits lean and clients happy.

What You Should Know

Depth Is Key: Shallow foundations (~1-5 feet) often dodge soils report mandates unless stability’s at risk. Over 5 feet? Expect scrutiny.

Project Type: Slab-on-grade structures (homes, warehouses, etc.) benefit most from this. Deeper piers or basements? Different story.

Note:

You’ll need a Texas licensed engineer to do the foundation plans and they will make the call as to the need for a soil report for the shallow foundations

Takeaway

For our project—and any structure with a foundation around 1 foot deep—we’re moving forward without a soils report (unless one is suggested by an engineer), aligned with COH’s typical approach. It’s a solid rule of thumb: keep it shallow, keep it simple. Got a building permit project in Houston or surrounding municipalities? Reach out—we’ll help you navigate the permit maze.

Unicorn Service Solutions – Your Houston Permitting Partner

Deeper Dive into COH Documentation

Here’s what I found by digging into COH resources:

Houston Building Code (2015, Appendix J):

Section J103.1: Permits are required for grading/excavation, but J104.5 ties soils reports to “engineered grading” (over 1,000 cubic yards) or building official discretion. Shallow digs (~1 foot) for small projects rarely hit this threshold.

Section J106.1: Excavations must be safe, but no fixed depth mandates a report—5 feet seems anecdotal, likely from COH staff interpreting stability needs.

Infrastructure Design Manual (IDM, 2023 Edition):

Chapter 9 (Geotechnical): Focuses on deep foundations (e.g., piles) and infrastructure like streets or utilities. Shallow slabs (~1 foot) aren’t highlighted unless tied to bigger grading work.

2024-2025 Review Cycle (proposals due Oct 31, 2024): No updates yet specify a depth threshold, but Chapter 9 revisions could clarify this.

Practical COH Threshold:

No explicit “5-foot rule” exists in writing, but it aligns with OSHA’s excavation standards (29 CFR 1926 Subpart P) and local practice for stability checks. COH likely uses it as a guideline for when soil analysis becomes critical, especially in clay-heavy Houston.

Remember, in the world of construction, time is money, and with the right permit management strategy, you can save both. Let Unicorn Service Solutions streamline your path to project completion in Houston. Call: 713-369-0925 or Start a City of Houston Permit project using our form >>