Second Story Additions

Add a floor, keep your lot.

Second story additions across Bellevue, Kirkland, Seattle and the Eastside. Principal-led by David Meade, designing additions here since 2000.

Free 30 minute consultation. You speak to the architect, not a salesperson.

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Why go up

When up is the only direction left.

On most Eastside lots, lot coverage is already close to the limit. Going up is how you add a primary suite or a second living floor without giving up the yard, and on a view lot it buys something a ground floor addition never can.

It is also the addition most likely to surprise you structurally. Houses built before 1980 were rarely framed to carry another floor.

The structure

The foundation decides the budget

Before anyone draws a plan, the question is whether your footings, shear walls and point loads can take the load, and what it costs to make them.

We verify in the field, because older framing frequently does not match the original drawings.

  • Footings widened or deepened where new posts land
  • Shear walls added or upgraded to current seismic code
  • A new beam line carried down to the foundation
  • Structural upgrades commonly add $30,000 to $100,000

What it costs

Second story cost, Seattle metro 2026

Partial second story, 400 to 700 sq ft$180,000 to $360,000
Full second story, 900 to 1,400 sq ft$320,000 to $600,000+
Bonus room over an attached garage$170,000 to $310,000
Per square foot of new space$350 to $550, up to $800 complex
Structural and foundation upgrades$30,000 to $100,000
Architect design fee12 to 20% of construction

Market ranges for planning, not a quote. Foundation condition, roof complexity and finish level explain most of the spread.

Free consultation

Find out if your house can go up.

One 30 minute call with David tells you the likely structural path and a realistic budget band, before you spend anything on drawings. No forms, no sales sequence.

Over the garage

Often the cheapest square footage

An attached garage already has the footprint and usually a simple roof, so building over it is frequently the cheapest real room you can add.

The catch is the slab. Garage footings were poured to carry a car, not a floor of living space.

Permitting

We package it so it moves

Kirkland addition permits commonly run 6 to 10 weeks in plan review with a complete package, submitted through MyBuildingPermit.com. Seattle targets 2 to 4 weeks for a medium complexity addition.

Incomplete submissions are the main reason additions stall, not city slowness.

  • Full structural, energy code and site plan package
  • Shoreline and critical areas review where it applies
  • We answer the city’s comments, you do not

Start here

Let us look at your house.

Free 30 minute consultation with David Meade, the architect who would design it. Call or WhatsApp direct.

Questions

Answered plainly.

How much does a second story addition cost on the Eastside?
Roughly $350 to $550 per square foot of new space, up to $800 on complex high finish work. A partial second story commonly runs $180,000 to $360,000 and a full floor $320,000 to $600,000 or more. Market ranges, not a quote.
Will my foundation support a second story?
Many Eastside houses built before 1980 need footing, shear wall or point load upgrades first, commonly adding $30,000 to $100,000. It has to be verified on site rather than assumed.
Do I have to move out?
For a full second story, usually yes, because the existing roof is removed. Partial additions over one wing can sometimes be staged so you stay in part of the house.
How long does the permit take?
Kirkland addition permits commonly run 6 to 10 weeks in plan review with a complete package. Design through permit is typically 4 to 8 months overall.
Is it cheaper to add up or out?
Out is usually cheaper per square foot. Up preserves yard and lot coverage and can gain views, which often makes it the better decision on a tight Eastside lot.
Do I legally need an architect?
Not always. RCW 18.08.410 exempts residential buildings of up to four dwelling units from the architect stamp requirement. What a licensed architect gives you is a permit package that does not come back with corrections.

Talk to a licensed architect in Kirkland, WA

Call 425 753 6452 WhatsApp