Pergolas are the fastest-growing segment of the Seattle outdoor living market — partly because they solve a real problem (Seattle rain) and partly because the product category has genuinely advanced. Motorized louvered aluminum pergolas that were a luxury item five years ago are now a mainstream option. Here's what the full cost range looks like and what drives the number.

Cost Ranges at a Glance

- **Basic cedar pergola (12×12, open slat roof):** $8,000–$14,000 - **Mid-size cedar pergola (16×20, with electrical):** $14,000–$22,000 - **Premium cedar pergola (custom, integrated lighting, fan):** $20,000–$35,000 - **Aluminum louvered roof pergola (motorized, waterproof):** $18,000–$50,000+ - **Vinyl/composite pergola:** $10,000–$20,000

These are installed costs including permit where required, concrete footings, and all labor. They don't include any associated deck work — if you're adding a pergola to an existing deck, the deck itself is a separate line item.

What Drives the Cost

Size

Pergola cost scales directly with square footage. The footprint — 12×12, 16×20, 20×24 — is the primary cost driver because every additional square foot means more posts, more beams, more rafters, and more labor. A 12×12 pergola (144 sq ft) costs roughly half of a 16×20 (320 sq ft) for the same material. Footprint is the single most controllable variable if budget is a constraint.

Roof Type

**Open slat cedar (traditional):** The lowest-cost option. Provides filtered shade and a classic PNW aesthetic, but offers no rain protection — which matters in Seattle. A cedar pergola will keep direct sun off you but won't stop Seattle drizzle. Maintenance requirement: staining every 3–5 years.

**Polycarbonate panels:** A translucent roof panel system that provides genuine rain cover at moderate cost ($2,000–$5,000 more than open slat). The panels transmit light while shedding rain — a good middle-ground for Seattle's drizzle. The aesthetic is more utilitarian than cedar slats, but functional year-round.

**Motorized louvered aluminum:** The premium category. Motorized louvers open and close via remote (or app) to control light, airflow, and rain shedding. Brands we work with include Struxure, Renson, and Louvretec. Cost premium is significant ($18,000–$50,000+ installed), but this is the only option that genuinely makes a Seattle deck usable 10–11 months per year. The louvers close fully when it rains; open when the sun comes out. For homeowners who want maximum outdoor living time despite Seattle's climate, this is the correct product.

Electrical

Adding lighting, ceiling fan, and outlet circuits to a pergola runs $1,500–$4,500 depending on the number of circuits and the distance from the electrical panel. The critical point: we run wiring inside the posts and beams during assembly, before everything is enclosed. Retrofitting electrical into a completed pergola later is significantly more expensive and disruptive. If there's any chance you'll want lighting or a fan, rough it in during the initial build.

Permit Requirements

Pergolas over 200 sq ft in most King County cities require a building permit ($500–$1,500 in fees). Attached pergolas — those connected to the house — always require a permit regardless of size. Freestanding pergolas under 200 sq ft are often permit-exempt, but this varies by city. Verify with your city's building department or ask us at the estimate — we confirm permit requirements on every project.

Cedar vs. Aluminum: Which Makes Sense in Seattle?

**Cedar:** Natural, beautiful, and well-suited to the PNW aesthetic. Requires staining every 3–5 years to maintain appearance and protect against moisture. Weathers gracefully to a silver patina if left untreated (some homeowners prefer this). Does not provide rain protection with an open slat roof. Best choice for homeowners who want the classic PNW look and are willing to maintain it.

**Aluminum louvered:** Zero maintenance for the life of the structure — aluminum doesn't rot, warp, or require finishing. Motorized operation. Actually keeps you dry. The aesthetic is more contemporary and architectural than cedar — not everyone prefers it. The cost is significantly higher. Best choice for homeowners who prioritize year-round usability and are willing to invest in the product that actually solves Seattle's rain problem.

The honest recommendation: if you want to use your outdoor space from March through November rather than June through September, the aluminum louvered pergola pays for itself in actual outdoor living time. If budget is the primary constraint and you primarily entertain in summer, cedar is the right call.

What to Expect from the Process

A standard cedar pergola takes 3–5 days to build after permit approval. Aluminum louvered systems take 2–4 days for installation once the structure is delivered (lead time on aluminum systems is 6–10 weeks from order). We handle permit applications and scheduling for both.

See our full [pergola services page](/pergolas) and [outdoor living page](/outdoor-living) for project examples. For cost comparisons with the associated deck, see our [deck cost guide](/deck-cost-seattle). If you're choosing a decking material to pair with a pergola, [cedar decking](/cedar-decking) naturally complements a cedar pergola structure.

Ready to talk through what makes sense for your space? [Contact us](/contact) for a free estimate — we'll bring photos of comparable projects and talk through the trade-offs for your specific lot.