Fairfax County Building Code 2026: Adopted Codes & Official Resources

First Check: Is the Property Actually in Fairfax County?

This matters because a Fairfax mailing address does not always identify the government that issues the building permit. Fairfax County and the independent City of Fairfax are separate permitting jurisdictions.

If the property is inside the City of Fairfax, use the city’s own Code Administration office rather than Fairfax County Land Development Services.

The same issue can arise around Alexandria. Some properties use an Alexandria mailing address but are physically in Fairfax County, while properties inside the independent City of Alexandria use a different permitting system. Our Alexandria, Virginia building department guide explains that separate process.

Fairfax County Adopted Building Codes for 2026

Virginia adopts the technical building-code framework at the state level, while Fairfax County Land Development Services administers and enforces the applicable requirements locally through plan review, permits and inspections.

Fairfax County’s adoption notice is available in Technical Bulletin 23-07. The Virginia Department of Housing and Community Development also maintains the official Virginia amendment documents.

How to Find the Correct Fairfax County Building Code Section

You normally do not need to buy a code book just to check a requirement. Fairfax County links to online code volumes that can be read through the ICC code library.

1. Confirm the project location. Make sure Fairfax County—not the City of Fairfax or another independent jurisdiction—is the enforcing authority.
2. Identify the building type. Decide whether the project involves a qualifying house/townhouse, commercial building, multifamily building or existing-building alteration.
3. Open the county’s Codes and Standards page. Choose the applicable 2021 Virginia code volume.
4. Use the code’s left navigation. Fairfax County specifically directs users to scroll through the code-volume navigation to locate the needed chapter and section.
5. Check Virginia amendments. The enforceable Virginia version can differ from the unamended model I-Code.
6. Check Fairfax-specific requirements. Review county ordinances, zoning, site rules, technical bulletins and local design criteria that affect the property or project.
7. Use the Permit Library before applying. The Fairfax County Permit Library identifies the correct PLUS record and required submission documents.
8. Use PLUS only after the project requirements are clear. Submit the application, plans and fees through Fairfax PLUS.

Which Code Should You Check for Your Project?

If you want a broader explanation of how state codes, model codes and local requirements fit together, see our city building code guide. Nearby jurisdictions may use the same Virginia statewide code cycle but operate different permit systems; for example, Arlington County building permits and inspections are administered separately from Fairfax County.

Fairfax County Local Design Load Criteria

For structural design, Fairfax County publishes local climatic and geographic criteria that designers should not replace with generic Virginia assumptions.

For site-specific seismic information, Fairfax County also points designers to the ATC Hazards by Location tool. Structural professionals should use the project-specific conditions required by the adopted code rather than treating a general county table as a complete structural design.

The State Building Code Is Only One Layer

Following the Virginia building code does not automatically establish that a project can be built at a particular location. Fairfax County lists additional county and site-development provisions that can affect permitting and plan approval.

• Chapter 61 — Building Provisions: local building administration and related provisions.
• Chapter 62 — Fire Prevention Code: county fire-related provisions.
• Chapter 65 — Plumbing and Gas Provisions.
• Chapter 67.1 — Sanitary Sewers and Sewage Disposal.
• Chapter 112.2 — Zoning Ordinance: use, setbacks, height, accessory structures and other land-use requirements.
• Appendix A — Floodplains: additional requirements for regulated flood-hazard areas.
• Appendix Q — Land Development Services Fee Schedule.
• Public Facilities Manual: standards affecting site development and public facilities.
• Erosion, stormwater, Chesapeake Bay and tree-conservation rules: potentially relevant when land disturbance or protected resources are involved.

Start with the county’s consolidated Codes, Ordinances and Regulations overview when the project involves more than ordinary interior work.

Important 2021 Code Snow-Load Guidance

Fairfax County currently publishes a specific caution about snow-load design under the 2021 Virginia Construction Code. This is important for engineers and plan preparers because the county does not allow the snow-load figures and design factors from different ASCE editions to be mixed.

The county further states that ASCE 7-16 and ASCE 7-22 snow provisions may not be mixed. Designers should review the current notice on the official Codes and Standards page before completing structural calculations.

When the Building Code Turns Into a Permit Requirement

Fairfax County requires permits for new residential, commercial and industrial construction and for many alterations and equipment installations. Common examples include additions, decks, garages, finished basements, structural alterations, electrical service changes, plumbing work and fuel-fired appliances.

Some detached residential accessory structures may qualify for a building-permit exemption based on size and use, but zoning and placement requirements can still apply. Do not treat “no building permit” as “no county rules.”

Micro Steps: Start a Fairfax County Building Permit

1. Open the LDS Permit Library.
2. Choose Residential or Commercial.
3. Select the actual project type, such as New Building, Addition/Alteration, Retaining Wall, Solar or a trade permit.
4. Read the project page before opening PLUS. Note the required plans, supporting documents, prerequisite approvals and record type.
5. Go to Fairfax PLUS and register for a free account if you do not already have one.
6. Select the Building area and create the record identified in the Permit Library.
7. Enter the property and project details carefully and upload the required drawings and documents.
8. Monitor PLUS for completeness comments, plan-review comments, fees and approval notices.
9. After issuance, download the approved plans and permit documents and keep them available for required inspections.

PLUS is the county’s central online platform for applications, payments, status tracking and electronic notifications. Fairfax County states that the older FIDO and PAWS systems have been replaced by PLUS.

Fairfax County Building Permit Fee Examples for 2026

Fairfax County adopted an updated Land Development Services fee schedule effective July 1, 2026. The final cost depends on permit type, construction type, project value, trade permits, plan review and any additional services.

These figures are useful for planning, but they are not a guaranteed project total. Mechanical, electrical, plumbing, fire, site-development or other charges can be separate. Review the county’s official July 2026 fee schedule PDF and use the actual PLUS invoice before paying.

Building and Trade Inspections

Required building, electrical, mechanical and plumbing inspections verify that work matches the approved plans and applicable code. Fairfax County states that scheduling required inspections is the permit holder’s responsibility.

The county uses combination inspections for related work. When multiple related inspections—such as concealment and associated trade inspections—are required at the same stage, they should be coordinated for the same day when county procedures require it. Improper scheduling can lead to a failed inspection or reinspection charge.

How to Request an Inspection

1. Open PLUS and sign in.
2. Open the issued permit record.
3. Select the available inspection function and choose the required inspection type.
4. Coordinate related building and trade inspections for the same construction stage where required.
5. Submit the request before 11:59 p.m. if requesting the next available business-day inspection under the county’s published procedure.
6. If plans change, work is incomplete or the date must change, cancel the existing request and schedule a new inspection rather than leaving an inspection active for unfinished work.

See the county’s Building and Trade Inspections page before scheduling.

What If the Code Is Unclear or Your Design Does Not Fit It?

Fairfax County provides formal processes for code interpretations, modifications and appeals. A modification is not simply permission to ignore a requirement. The Building Official may consider an alternate approach when it meets the intent of the applicable code and satisfies the county’s approval criteria.

A modification may be relevant when:

• a proposed design does not meet the literal wording of a provision but is intended to meet its functional purpose;
• an alternate design, material or method is not directly addressed;
• a provision in another code edition better addresses a particular technical condition; or
• a project-specific code interpretation needs formal resolution.

For a formal request, review Code Interpretations, Modifications and Appeals. Fairfax County’s PLUS procedure for a modification starts under Building → Create an Application → Administrative → Code Modification.

Check Technical Bulletins Before Finalizing Plans

Fairfax County uses technical bulletins to announce code interpretations, policy changes and revised construction or review procedures. This is especially useful for professionals because a recent bulletin can affect the practical review process even when the basic code edition has not changed.

Open the county’s Letters to Industry / Technical Bulletins and scan the newest entries before submitting a significant project.

Fairfax County Building Code Contacts

Fairfax County Building Code FAQs