Second Story Addition in Seattle, WA — Costs $121,773 to $761,083

What does second story addition cost in Seattle? Average $304,433, ranging $121,773–$761,083. Labor runs $49.93/hr locally — 52% above the national average. Free breakdown with material + labor split.

Seattle, WA Market

+52% vs national

Labor Rate

$49.93/hr

Material Index

138

Avg Permit Cost

$2,240

Median Home Price

$616,441

As one of the largest metros in Washington, Seattle has a competitive contractor market with hundreds of licensed professionals. This typically gives homeowners more leverage on pricing, though high demand for renovations can offset that advantage. At 52% above the national average, Seattle is one of the more expensive markets for home improvement — driven primarily by above-average labor rates in the region. With a median home price of $616,441, this second story addition represents just 49.4% of typical home value — a relatively small investment that can significantly boost curb appeal or functionality.

Low Estimate

$121,773

National: $80,000

Mid-Range

$304,433

National: $200,000

High End

$761,083

National: $500,000

Per Sq Ft

$457

National: $300

Duration: 4-8 months
DIY: Hard
Permits: Required
ROI: 60%

Second Story Addition Cost Calculator for Seattle

Adjusted for Seattle's labor rate ($49.93/hr) and material costs (index 138).

50 sq ft1,000 sq ft

Mid-grade materials, good quality fixtures, standard options.

Estimated Total in Seattle

$304,433

Based on 200 sq ft at mid quality, adjusted for Seattle market rates.

Local Cost Breakdown

Labor (50%)$152,217

At Seattle's average rate of $49.93/hr (66% above national avg)

Materials (50%)$152,217

Material cost index 138 (38% above national baseline of 100)

Second Story Addition vs. Home Value in Seattle

MetricSeattleNational Avg
Second Story Addition (Mid-Range)$304,433$200,000
Median Home Price$616,441$350,000
Project as % of Home Value49.4%57.1%
Estimated ROI60%60%
Median Household Income$106,476$75,000

What Affects the Price in Seattle

  • 1Local labor rates ($49.93/hr in Seattle)
  • 2Material cost index (138 vs national 100)
  • 3Total square footage added
  • 4Structural reinforcement of first floor
  • 5Staircase addition
  • 6Roof removal and replacement

Popular Upgrades

  • Master suite
  • Additional bedrooms
  • Jack-and-Jill bathroom

Planning a Second Story Addition in Seattle

Building permits are typically required for a second story addition in Seattle. The average permit fee in this area is $2,240, though costs vary based on project scope. Permit fees in this market are above average — factor them into your total budget. Plan for 4-8 months from start to finish.

A second story addition is a complex project best left to licensed professionals. In Seattle, skilled contractors charge an average of $49.93/hr, and the specialized nature of this work means cutting corners on labor can lead to costly rework.

With a median household income of $106,476, many Seattle residents can budget for this project through savings. The mid-range cost of $304,433 represents 286% of the typical household's annual income.

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