EPDM Roofs in Chantilly, VA: What the Area Plan Says
Chantilly's biggest flat roofs sit on office, flex and industrial buildings along Route 28 and in Westfields. Fairfax County's plan for that area says very little about roofs. Here is what it says, and what to do with the silence.
The one roof sentence
Which sentence in the Dulles Suburban Center plan touches a rooftop?
Under Buffers and Screening, the design guidelines for Land Units A through K say: “Screen from public view rooftop mechanical equipment, materials storage, utility substations and similar facilities.”
Fairfax County Comprehensive Plan, Area III, Dulles Suburban Center, amended July 14, 2026; read October 14, 2026.
The county's page calls the plan a guide to decision-making on land use. Whether a given roof job must follow a plan sentence is a question for county planning staff.
Assumption check
Five things people assume about Westfields roofs, and what the plan text shows
Westfields has its own roof standard.
Land Unit J is 1,156 acres, almost entirely the Westfields International Center office park. Its text never uses the word roof. It asks only that new development match the existing character.
The plan requires green roofs.
Green roofs appear once, in Land Unit A near the future Innovation Center station, as one of many green building practices that “should be encouraged.” The area-wide stormwater section lists vegetated roofs among low impact practices that are “not limited to” a list. Neither is a Westfields rule.
The big flat roofs here are all rubber.
Nothing. The plan names no roofing material, and the Census does not count commercial roofs. Ask the building owner for the membrane's name in writing instead of guessing from the street.
A ZIP 20152 building is covered by the same plan.
It is Fairfax County's plan, and the area's southwestern edge is contiguous with Loudoun County and Dulles Airport property. A Loudoun parcel answers to Loudoun. Our Sterling EPDM page reads Loudoun's rooftop equipment text.
Westfields is all offices.
Land Unit J offers an option for housing, about two thirds apartments, with conditions and no date.
At the membrane
What does a roof with screened equipment ask of a rubber sheet?
These three signs draw on model-code and trade-association text, plus our own reading where marked.
Water left beside a unit
- What you see
- A damp patch or stain around an equipment curb after rain.
- What it can mean
- The Asphalt Roofing Manufacturers Association says ponding can come from rooftop equipment runoff. Its listed fixes include crickets upslope of equipment and piping air conditioning condensate to proper drains. It was written for asphalt roofs, so ask the membrane maker about yours.
- Who to ask
- The roofer who last looked at it, with dated photos.
A new screen wall or raised edge
- What you see
- Metal or masonry added around the units, or edge metal replaced during a roof job.
- What it can mean
- The 2021 model code says edge metal on low-slope single-ply roofs must be designed for wind loads and tested to ANSI/SPRI ES-1. The plan sentence gives no such detail.
- Who to ask
- The designer.
A unit moved, swapped or added
- What you see
- A new curb, a new pipe, a patch near an old one.
- What it can mean
- Our reading: every curb and pipe is another place where sheet meets flashing, so a roof with more equipment has more places to inspect.
- Who to ask
- Whoever signs for the roof.
Seams and reroofing limits live in the flat roof guide and the materials comparison.
Who signs
In a Chantilly apartment building, who decides about the roof?
Census 2024 five-year estimates, table B25032, for the Chantilly place. It counts occupied homes, not roofs, and it does not tell us which buildings have flat ones.
| Building size | Owner-occupied | Renter-occupied |
|---|---|---|
| One house, detached or attached | 5,583 | 779 |
| 2 to 4 units | 80 | 78 |
| 5 to 19 units | 27 | 292 |
| 50 or more units | 66 | 276 |
Add the 5-to-19 and 50-plus rows: 568 of the 661 occupied homes in larger buildings are rented, about 86 percent by our arithmetic. There the person under the roof is rarely the one who signs for it; an owner, manager or association does.
Next calls
Three calls, in this order
First: the owner or manager
Ask which membrane is on the roof, what sits on it, and whether any equipment is planned.
Stop here if they hold a written roof descriptionSecond: the county for the parcel
Fairfax County Planning Division, 703-324-1380, asks for the Planner of the Day; Loudoun County Building and Development is 703-777-0220 for ZIP 20152. Ask whether a screening change needs review.
Third: us
Tell us the building type and what is on the roof. Our work leans residential.
FAQ
Questions about the area plan and a Chantilly rubber roof
Does the plan make Westfields owners hide rooftop equipment?
It says to screen it from public view. The county describes the plan as a guide to land use decisions, so ask planning staff whether your project is held to that sentence.
Does the plan say anything about EPDM?
No. We searched the Dulles Suburban Center text for EPDM, rubber, membrane and single-ply and found none of them.
Where does the plan mention green roofs?
In the Land Unit A green building list near the Innovation Center station area, and as one low impact stormwater practice in the area-wide section. Westfields is Land Unit J, whose text has no roof words.
Why does equipment on a flat roof matter to a rubber sheet?
Standing water can come from runoff off units, and each curb and pipe is a flashing point. Take dated photos and ask the roofer.
My building is in ZIP 20152. Which plan do I read?
Not this one. It is Fairfax County's, and Loudoun parcels answer to Loudoun. Confirm the county from the parcel record first.
Does the Census count Westfields offices?
No, it counts homes. How the census place lines up with the office park is unchecked.
Pages read
Which pages did we open for this Chantilly EPDM guide?
Checked October 14, 2026.
- Fairfax County Comprehensive Plan: Dulles Suburban Center
- Fairfax County: Comprehensive Plan overview
- Census Reporter: table B25032, Chantilly place
- Asphalt Roofing Manufacturers Association: ponding water bulletin
- 2021 International Building Code, chapter 15
Back to roofing in Chantilly. The same city's metal roofs page sorts by pitch, and Reston's EPDM page reads that area's own design standards. See all service areas.
Talk through the next step
Bring the building type and the ZIP
Tell us the street, whether the roof is on a house, an apartment building or an office, and what sits on top of it. A short phone call comes first.
9220 Topaz St, Fairfax, VA 22031
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