Whether you’re building a new home, adding an accessory structure, or just applying for a permit, a well-prepared site plan is critical. It’s the foundation of a smooth project and can mean the difference between a quick approval and a drawn-out correction process. Yet even experienced professionals run into avoidable mistakes.

Here are five of the most common site plan mistakes — and how to steer clear of them:

1. Incorrect or Missing Property Lines

The Mistake:

It’s surprisingly common for site plans to be drawn without accurate property boundaries — or worse, with assumed or outdated lines pulled from a previous drawing.

The Fix:

Always base your site plan on a current survey from a licensed land surveyor. If that’s not available, request a plat from the county or municipality to verify property lines before you start drafting.

2. Ignoring Setback Requirements

The Mistake:

Placing structures too close to property lines, easements, or rights-of-way is one of the fastest ways to get your permit denied.

The Fix:

Before you start your layout, check the local zoning code for setback rules — front, rear, and side. Be especially careful with corner lots and flag lots, which often have special conditions.

3. Improper Drainage Planning

The Mistake:

Failing to account for water flow on the site can cause major headaches later, including grading issues, erosion, and neighbor complaints.

The Fix:

Include spot elevations, contour lines, and drainage arrows when needed. Make sure runoff flows away from buildings and toward approved drainage points. If you’re unsure, consult a civil engineer or local stormwater guidelines.

4. Inaccurate Structure Placement

The Mistake:

A few feet off might not sound like much — until it’s discovered mid-construction that the garage encroaches into a setback or utility easement.

The Fix:

Double-check dimensions from known, fixed points like property corners. Use control points that are easy to verify in the field, and clearly indicate distances to all proposed structures.

5. Missing Key Details Required by the Permit Office

The Mistake:

Site plans are often rejected simply because they lack required information — things like north arrows, scale, driveways, utility connections, or tree protection zones.

The Fix:

Check your local jurisdiction’s submittal checklist. Each city or county has its own requirements, and they’re usually available online. A quick review can save you days or even weeks of delay.

Final Thoughts

Creating a solid site plan isn’t just about drawing lines on paper — it’s about translating the big picture into a form that’s clear, buildable, and code-compliant. Take your time, double-check the details, and collaborate with surveyors, engineers, or designers when needed. In the long run, a clean site plan can save you time, money, and frustration.