Fairfax County residential building permit plan requirements

A Fairfax County residential plan set goes in through PLUS as a PDF at 1/4 inch = 1 foot or larger, on sheets at least 11 by 17 inches. ^S1S2 It must state the code year, name the designer, and include a wall bracing method and worksheet, insulation R-values and U-factors, and truss shop drawings. ^S1 A site-related plan or plat is a separate requirement. ^S2S3

What does Fairfax County require on every residential plan set?

Every residential submission must show the nature of all the work, at a minimum scale of 1/4 inch = 1 foot. ^S1 The county lists these items for all plans:

• Code year used for the design. ^S1
• Name, address and occupation of the building designer. ^S1
• Project name and address of the building. ^S1
• An embedded digital signature, seal and date, if a Virginia registered architect or professional engineer prepared the plans. ^S1

You must apply through PLUS, the county's online permitting system. ^S1

What extra items does a residential plan set need?

Residential plans also need a Building Plan Review Cover Sheet, a wall bracing method and worksheet, insulation R-values and U-factors, and residential truss shop drawings. ^S1 The county's checklist says the cover sheet should be at least 11 by 17 inches. ^S2

The county's code year is the 2021 Virginia Uniform Statewide Building Code (USBC). Its administrative provisions took effect January 18, 2024. ^S4 Since January 18, 2025, all applications and plans must meet the 2021 USBC, and mixing technical provisions from the 2018 and 2021 editions is prohibited. ^S4 For the next edition (2024 USBC), DHCD's schedule, which is tentative, lists October 2027. ^S5

What goes on the sheets for a new single-family house?

The county's checklist for a new residential single-family dwelling lists:

• PDF structural and architectural plans, 11 by 17 inch sheets minimum, scale 1/4 inch = 1 foot. ^S2
• The Fairfax County building plan review sheet. ^S2
• A digital protected seal and signature, if applicable. ^S2
• A PDF of the site-related plan. ^S2
• A geotechnical report, if applicable. ^S2
• Foundation plan. ^S2
• Framing plans for floor and roof. ^S2
• Wind bracing plan. ^S2
• Each room labeled as to proposed use. ^S2
• Window and door sizes. ^S2
• Columns, beams and header sizes shown. ^S2

The county checklist was last updated June 2021, so confirm with the county that it is still the current one.

What goes on the sheets for an addition, deck, porch or sunroom?

The same checklist has a separate block for residential additions, decks, porches, sunrooms and accessory structures. ^S2 It lists:

• PDF plans at 11 by 17 inches minimum, scale 1/4 inch = 1 foot. ^S2
• A digital protected seal and signature, if applicable. ^S2
• A site-related plan. ^S2
• Foundation plan. ^S2
• Framing plans for floor and roof. ^S2
• Wind bracing plan. ^S2
• Each room labeled as to proposed use. ^S2
• Window and door sizes. ^S2
• Columns, beams and header sizes shown. ^S2

Fairfax also publishes pre-approved typical details for decks, finished basements, carport enclosures and retaining walls. These can be used in place of an architectural plan submission. ^S6 See our guides on deck plans and on basement finish and addition plans for the specifics.

Do I need a sealed drawing?

Not always. The county says a registered design professional (a Virginia licensed architect or professional engineer) must seal unique structural designs. ^S7 Where no seal is required, the drawings must list the name, occupation and address of the designer. ^S7 The Building Official can require sealed drawings regardless of the published tables. ^S7 A Virginia registered architect or engineer must sign and seal their own drawings regardless of those tables. ^S7

For electronic plans, the county says the seal and electronic signature with signature protection goes on each sheet, or only the cover sheet if it has a table of contents. ^S7

What site plan or plat goes with a residential permit?

When a new structure or exterior change is proposed, a site-related plan or survey/plat is required in addition to the building permit. ^S8 Which one depends on how much land you disturb. ^S3

A house location plat is submitted in PLUS during the building permit application for projects under 2,500 square feet of land. ^S3 It must be drawn to a scale of not less than 1 inch = 50 feet. ^S3

Calculate disturbed area as the project footprint plus a 10-foot work zone around all sides. ^S3

Who can pull the permit, and what else can hold it up?

If the work is valued at $1,000 or more, the person doing it must hold a valid Virginia contractor's license from DPOR. ^S8 A contractor working in Fairfax may also need a county Business, Professional, and Occupational License. ^S8

Projects in the Town of Vienna need coordination between the town and the county. The county handles building permit review and inspections. The town handles site-related plans such as grading plans. ^S8

How does a plan set get a second look before you submit?

Check your own set against the county's list, then check it against the county's own residential comment list. ^S9 That list shows comments reviewers write, and the county publishes no data on how often each one comes up. Our guide on why Fairfax County sends plans back walks through it. LDS also publishes a memo of common intake and plan review comments, dated September 28, 2026, that says its goal is fewer review cycles. ^S10

FAQ

PlanScan is an invite-only pilot that reads a residential plan set PDF and flags likely code issues, each with a citation, for Fairfax County only. Its rules are drafts, and it does not replace county review.