A flat roof in the City of Fairfax: can the street see it?
The City’s Design Guidelines name rubber membranes and built-up roofs as common materials, and then allow them only on roofs “not visible from public areas.” For a flat commercial or apartment roof, that sentence comes before any product choice.
The same rule appears in all three districts
The Old Town Historic Overlay, the Transition Overlay and the Architectural Control Overlay, which is the rest of the City, each say that rubber membrane or built-up roofs can be used on flat or sloping roofs that are not visible from public areas. This is a City of Fairfax document. A Fairfax mailing address in the county is outside it.
What the Guidelines say about flat roofs, and what they leave out
Every membrane sentence sits in a chapter for new construction. The roof chapter for existing historic buildings talks about standing seam metal, slate, repairing in kind and matching the old covering. It does not mention membranes, and TPO, PVC and EPDM are not named anywhere in the text. So whether a white thermoplastic sheet counts as a “rubber membrane” is a question for City staff, with the product sheet in hand, not something we can promise.
The approval that matters is the Certificate of Appropriateness. The Guidelines require it for significant changes to features visible from the right-of-way or public property. They do not define “significant,” so ask whether a new cover on a flat roof you can see from the street counts.
Two kinds of flat roof
Behind a parapet, or in plain sight
Hidden behind a parapet
- What the text says
- Small infill commercial buildings should usually have a flat roof, or a sloped one, behind a parapet wall.
- Where membranes fit
- This is the case the membrane sentence describes: roofs not visible from public areas.
- Still ask
- How the City judges “not visible” from the sidewalk and from neighboring lots. The text gives no parapet height.
Seen from the street
- What the text says
- Smaller commercial and office buildings and multifamily developments often have very visible roofs. On visible roofs the Guidelines point to standing seam metal, architectural shingles, slate or artificial slate.
- Where membranes fit
- The text does not offer them for this case.
- Still ask
- Whether your roof is flat enough, and set back enough, to count as hidden.
Questions to put to the City, in this order
- Is the parcel in a district that reviews this building?Single-family detached homes outside the Old Town district, and duplexes and townhouses after they are first built, are exempt. Commercial and multifamily buildings are not.
- Is the roof visible from a public area?Bring photographs from the sidewalk, not just from the roof.
- Is a new cover a “significant” change?The text leaves the word open.
- Does equipment on the roof show?The Guidelines ask that roof-mounted mechanical equipment be screened on all sides or kept behind a parapet or back from the edge.
- Has the pre-application meeting happened?The Guidelines require one with Community Development and Planning staff. Building permits may not be issued until after Board approval.
- What does Code Administration need?It issues residential and commercial construction permits, and its permit page has no roof line. Call (703) 385-7830 with the scope.
Why two offices answer one flat roof
Design review and building permits are separate. Board approval does not replace a construction permit, and a permit waits for the approval. Code Administration also says the state sets construction codes and the City cannot change them.
The Fire Marshal’s side has its own page. It says the Fire Prevention Code applies mainly to commercial and industrial facilities and to common areas of multifamily buildings, and that it does not modify construction materials or methods covered by the building code. Roof-covering questions therefore start with Code Administration.
A building at a county address with a Fairfax mailing city belongs to Land Development Services, 703-222-0801, and none of the City Guidelines text applies. For how membranes are built, drained and permitted across the region, read our flat roof guide. The hub page holds the City permit table: Roofers in Fairfax, VA. For the metal side of the same Guidelines, see metal roofs in Fairfax. A neighboring city with its own rulebook is covered in TPO roofs in Falls Church.
Questions
Flat-roof questions Fairfax owners ask
Do the City Guidelines name TPO?
No. They name rubber membranes and built-up roofs of tar and gravel. TPO, PVC and EPDM do not appear, so ask staff how your product is classed.
Does a flat roof behind a parapet count as not visible?
The Guidelines describe roofs hidden behind parapet walls and ask for equipment to sit behind them. They give no height or sightline test, so staff decide from your photographs.
Do the rules cover re-covering an existing flat roof?
The membrane sentences are in the new-construction chapters. The existing-building roof chapter does not address membranes, so ask whether a re-cover is treated as a significant change.
Do townhouses and duplexes need Board review for a roof?
The Guidelines exempt duplexes and townhouses after their initial construction, and single-family detached homes outside the Old Town district. Permit questions still go to Code Administration.
Does Board approval replace a building permit?
No. The Guidelines say approval does not take the place of construction permits, and permits may wait until after it.
Does the Fire Marshal review the roof covering?
The City page says the Fire Prevention Code does not modify materials or methods regulated by the building code. Start with Code Administration.
Do these Guidelines apply at a county address?
No. They are a City of Fairfax document. County addresses go to Land Development Services.
Official pages used
Checked October 11, 2026: City of Fairfax Design Guidelines (2018), Code Administration, Permit FAQs, Fairfax County, when a permit is required.
Talk through the next step
Bring the street view and the product sheet
Tell us which Fairfax the building is in, whether the roof sits behind a parapet and what covers it today. A short phone call sorts out the questions to ask the City before anything is ordered.
9220 Topaz St, Fairfax, VA 22031
Mon to Fri 7 AM to 8:30 PM, Sat 7 AM to 8 PM, closed Sunday