PVC roofs in Leesburg, VA: which Crescent District buildings can even have a flat roof?
The Town’s Crescent Design District ordinance never names PVC or any other membrane. It does decide which building types may have a flat roof, and what has to surround it.
Which roof does the ordinance set for each building type?
| Building type | What the ordinance says about the roof | Is a flat-roof membrane in play? |
|---|---|---|
| Single family detached | “Shall have a pitched roof.” | No, except a small low-slope part such as a porch top |
| Townhouse and multifamily | “May have a pitched, flat or shed roof.” Townhouse groupings also need dormers on at least half the buildings. | Yes, if the building chose a flat or shed roof |
| Commercial and mixed use | One or more of gabled, hipped, mansard, pitched, or shed or flat. A flat roof must have a decorative cornice and be enclosed by a parapet. | Yes, behind the parapet |
| Drive-through building, service station | The single-story drive-through building needs a pitched roof, its lane canopies are pitched, and a service station is “required to have a pitched roof.” | No on the main roof |
| Accessory building | Roof pitch equal to or greater than the principal building’s. | Follows the main building |
The ordinance does not say which Crescent buildings actually chose flat roofs, so this table tells you what is allowed, not what is overhead. Your own roof plan answers that.
Three limits on what sits on top of the roof
- Half the floor belowSec. 7.10.6.N
- On a flat roof, the penthouse or screened area holding HVAC and mechanical equipment is limited to fifty percent of the area of the floor below.
- Under a 45-degree lineSec. 7.10.6.N
- It sits back from the front and back facades so the top of the screen falls below a 45-degree line drawn from the bottom of the parapet.
- Twelve feet at mostSec. 7.10.8.C.1
- Rooftop equipment on a flat roof is contained in a penthouse or screen wall no taller than twelve feet.
- These limits decide where roof traffic, curbs and pipe penetrations cluster, which is where a sheet roof gets its extra seams and flashings. A re-cover plan should show every unit and curb against the parapet line.
The sentence that decides a flat roof here
“Shed or Flat roofs, which shall include decorative features such as a parapet (cornice, entablature, and coping). At a minimum, flat-roofed buildings shall have a decorative cornice and the flat roof shall be enclosed by a parapet.”
Town of Leesburg Zoning Ordinance, Article 7, Sec. 7.10.6.E.1, page 7-41 (archived copy of the February 2024 edition).
For a PVC sheet, the parapet is where the membrane ends and where the Town’s design wording and the roofer’s edge details meet. Our flat roof guide shows how a sheet turns up that wall.
“Encouraged” is not “required,” and no membrane is named
Section 7.10.7.A says colored roofing materials that have a high reflectance value are encouraged, and that roofing should complement the building. That is a preference about color and reflectance. It does not say PVC, and color alone does not tell PVC from TPO or EPDM, because single-ply sheets come in white, black and other colors.
Whom to ask, and in what order
First: the Town’s zoning staff, (703) 737-7183
Ask which Crescent sub-district the parcel sits in, and whether the building predates the district and counts as an existing nonconforming structure. Section 7.10.2.G.4 exempts maintenance and repair work on those from the Crescent design standards and lists “roof or window replacement” among the exempt activities.
If they say it is exempt, the parapet and equipment rules above are background, not a checklistSecond: Preservation staff, if the parcel is designated H-1
Properties designated H-1 stay under the Old and Historic District rules inside the Crescent District. The metal roofs page reads that wording.
Third: Loudoun County, for the building permit
The Leesburg roofing page sorts the county and Town counters. Bring a roof plan showing the parapet, each curb and unit, and the part that is low-slope.
Then: the contractor, on paper
For PVC, the model building code’s single-ply table lists ASTM D4434; ask for that standard on the data sheet.
Questions about PVC and the Crescent District
Does the Crescent Design District ordinance mention PVC?
Not in the sections we read. Its roof lines concern roof forms, parapets, equipment and color, and name no membrane.
Can a Crescent townhouse have a flat roof?
Yes. Single family attached and multifamily buildings “may have a pitched, flat or shed roof.” A flat one still needs the parapet and cornice described above.
Does the ordinance say how tall a parapet must be?
Not in the roof sections read. It requires that a flat roof be enclosed by a parapet and ties the equipment screening to a 45-degree line from the parapet.
Do the design standards apply when only the roof covering is replaced?
Section 7.10.2.G.4 exempts repair and replacement work on existing nonconforming structures. Confirm with zoning staff that your building is one.
Is a white PVC sheet required in the Crescent District?
Nothing in the ordinance says so. It only encourages colored roofing with high reflectance, and says roofing should complement the building.
What does the ordinance say about vents, skylights and solar panels on a Crescent roof?
The roof-form list says they “shall be placed inconspicuously.” It sets no size, count or distance.
Is the Crescent District the same as the Gateway or Old and Historic District?
No. The Crescent Design District is a zoning district in Article 7. The Gateway guidelines are read on the TPO roofs page and the Old and Historic District wording on the metal roofs page.
Keep reading
The Leesburg roofing page covers the county and Town split. For how sheet roofs are built, see the flat roof guide and the Northern Virginia single-ply guide. The EPDM page looks at who decides the roof by building type. Nearby offices have their own PVC pages: Reston and Great Falls.
Sources, checked October 14, 2026. The Town’s server refuses automated downloads, so the ordinance text comes from an archived copy of the Town’s Article 7 PDF, the February 2024 edition, captured by the Internet Archive; page numbers are those printed in the document. The Town’s current Crescent Design District page links a newer file that is not in the archive, so check the current edition before relying on a number. Crescent Design District page (archived copy), Zoning Ordinance Article 7 (archived copy), 2021 International Building Code, Chapter 15.
Talk through the next step
Talk through your roof with King's Roofing
Share the address, what you are seeing on the roof and the decision you need to make. We will tell you what to expect before anything is scheduled.
9220 Topaz St, Fairfax, VA 22031
Mon to Fri 7 AM to 8:30 PM, Sat 7 AM to 8 PM, closed Sunday