Composite Deck Cost by Size and Tier
Below are full installed costs for the four most common composite deck sizes in Loudoun, Fairfax, Prince William, Arlington, and Alexandria. Tiers are budget (Trex Enhance / Fiberon Good Life), mid (Trex Transcend / TimberTech PRO), and premium (Trex Signature / TimberTech AZEK Vintage).
300 sqft (e.g. 15×20)
$278–$405 /mo (10y)Standard family deck for a townhouse or smaller single-family yard.
400 sqft (e.g. 20×20)
$342–$481 /mo (10y)Mid-size deck with seating zone, grill area, and dining table.
500 sqft (e.g. 25×20)
$405–$570 /mo (10y)Large entertaining deck with multiple zones, pergola-ready.
600 sqft (e.g. 20×30 or 24×25)
$481–$696 /mo (10y)Premium outdoor living space — two zones, often two stair flights, room for built-ins.
Why Cost Doesn't Scale Strictly Per Square Foot
A 600 sqft deck does not cost 2× a 300 sqft deck. Larger decks add features that smaller decks rarely need — more railing linear feet, two stair flights, deeper framing, more concrete footings, and often built-in seating or planters. Conversely, the per-square-foot cost on small decks (under 250 sqft) is often higher because permits, mobilization, and design overhead are roughly fixed regardless of size.
- Railings: $40–$150 per linear foot — bigger decks have proportionally more
- Stairs: $1,500–$4,000 per flight — bigger decks often need a second flight
- Lighting: $1,500–$5,000 — scales with deck perimeter, not surface area
- Footings: One additional footing per ~100 sqft of new deck
- Permits: Roughly flat $300–$1,500 across all sizes
What Drives the Tier Choice
The tier (budget vs mid vs premium) is usually the biggest single driver of total cost. For Northern Virginia homeowners staying in the home 10+ years, mid-tier is the sweet spot — Trex Transcend or TimberTech PRO Reserve carry 25-30 year fade & stain warranties and look indistinguishable from premium tiers at normal viewing distance. Premium pays off if you want the 50-year AZEK Vintage warranty or the deepest grain pattern. See the full composite deck cost guide for tier detail.
Size-Specific Cost Guides
We publish dedicated cost pages for the most common Northern Virginia deck sizes:
- 400 sq ft deck cost in Northern Virginia →
- 600 sq ft deck cost in Northern Virginia →
- 800 sq ft deck cost in Northern Virginia →
Estimate Your Monthly Payment
Once you have a size + tier picked, drop the project amount into the deck payment estimator to see the monthly payment at different APRs and terms. Use the deck cost calculator first to refine the project amount itself.
Related Cost & Material Guides
- Composite Deck Cost in Northern Virginia →
- Wood vs Composite: 15-Year Cost Analysis →
- Trex Decks — Platinum Partner →
- TimberTech & AZEK Decks →
- Deck Financing Options →
FAQ
How much does a 300 sqft composite deck cost in Northern Virginia?
A 300 sqft composite deck in Northern Virginia runs $16,500–$38,000+ depending on tier. Budget composite (Trex Enhance, Fiberon Good Life) lands $16,500–$24,000. Mid-tier (Trex Transcend, TimberTech PRO) runs $22,000–$32,000. Premium (Trex Signature, AZEK Vintage) runs $28,000–$38,000+.
How much does a 400 sqft composite deck cost?
A 400 sqft composite deck in Northern Virginia typically runs $20,000–$46,000+. Pricing scales roughly linearly with size, but a 400 sqft deck often includes an extra stair flight, deeper joists, and more railing — which adds $2,000–$5,000 over a strict per-square-foot calculation.
What does a 500 sqft composite deck cost installed?
A 500 sqft composite deck in Northern Virginia runs $24,000–$55,000+. At this size, picture-frame borders, multi-zone layouts, lighting packages, and railings become a larger share of the total cost. Most 500 sqft projects land in the mid-tier $32,000–$45,000 range.
How much does a 600 sqft composite deck cost?
A 600 sqft composite deck in Northern Virginia runs $28,000–$70,000+ installed. Decks this size almost always include two stair flights, a more complex framing plan, full railing system, and often built-in seating or planter benches that add to the project amount.
Does the cost scale linearly with size?
No. Larger decks have proportionally more railing, more stairs, deeper framing requirements, and more lighting. A 600 sqft deck typically costs ~1.7–1.9× a 300 sqft deck of the same tier, not 2× — but it also adds features that smaller decks rarely include.
What size deck do most Northern Virginia homeowners build?
Most new builds and replacements in Loudoun, Fairfax, and Prince William counties land in the 300–500 sqft range. Townhouse decks cluster at 200–300 sqft. Single-family backyards typically go 400–600 sqft. Custom estate properties build 600–1,000+ sqft.
How do I estimate the monthly payment for my size?
Pick the size + tier from the table above to find the project amount range, then run that number through the deck payment estimator. Most lenders run 8–11% APR over 10 or 15 years for home-improvement financing in this credit range.
Estimate Project Payment by Size
Drop the project amount for your size + tier into the payment estimator.
Open the Deck Payment Estimator →