• Blake D. DeMarr, P.E.

When are Civil Engineering Plans required in Fairfax County?



Improvements to your residential Fairfax County property will inevitably cause land disturbance during the construction and landscaping process. Depending on how much land you disturb and the category of work your project falls under will determine whether engineering plans and county approval are required. Not obtaining proper plans, permits and approvals will result in costly delays and violations to your project. We are here to help navigate your project through the proper process.




A General Rule of Thumb . . .


If land disturbance is greater than (>) 2500 Square Feet, a Civil Engineering Plan and Permit is required for Fairfax County approval. There are 2 different types of plans for this case:


  • Rough Grading Plan (RGP) - If you are not building a new home and are disturbing land under an existing use, then you will need a Rough Grading Plan. Fairfax County will review this plan for compliance with applicable codes and issue a Land Disturbance Permit upon approval of the RGP. Typical RGP Projects are for demolition, drainage solutions, and landscape improvements greater than (>) 2500 Square Feet.

Figure 1: Sample Detail from a Fairfax County Rough Grading Plan.


  • Infill Grading Plan (INF) - If building a new home, you will need a full INF plan set. This complete plan set will cover everything from specifying what features will be removed from the property, the proposed house location and elevation, tree preservation and planting, stormwater evaluation/management, and a Limited Geotechnical Study.


Figure 2: Stanley Martin Custom Homes Architectural Drawing (www.webuildonyourlot.com)



Site Related Plan Approval Process

The general site-related plan approval process for Fairfax County is shown below. As soon as the design plans are finalized, we submit to Fairfax County for review. The site review process will typically takes 4-6 weeks for review and approval before proceeding to permitting. Site permits are typically obtained within 1-2 weeks after plan approval.


Do you have any questions on what your project will require? We can help!


Send us and email to info@demarr-engr.com or give us a call at (703) 214-7220.


This article is brought to you by DEMARR Engineering, PLLC, a Northern Virginia Civil Engineering Firm. For a list of Civil Engineering and Land Surveying services we provide in Fairfax County and the rest of Northern Virginia, visit https://www.demarr-engr.com or email us at info@demarr-engr.com for more information.

© 2020 by DEMARR Engineering, PLLC. 

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