1. Convert Existing Spaces (Basements, Attics, or Garages)
Lowest cost per square foot
- Why it’s cheap: No need for a new foundation, exterior walls, or roof.
- Basement remodels in the Seattle area are especially smart—most homes already have one, and they’re protected from weather.
- Common uses: Add a guest suite, family room, home office, or rental unit (ADU).
- Watch out: You’ll still need to meet egress and ceiling height requirements to make the space legal and safe.
2. Bump-Out Additions
Budget to mid-range
- A small extension of an existing room (like a kitchen or bathroom).
- Why it’s smart: It avoids full-scale foundation work or HVAC system extensions.
- Great for: Expanding a cramped kitchen, adding a breakfast nook, or enlarging a bathroom.
3. Sunroom or Three-Season Room
Lower-mid cost
- Offers light-filled living space without the price of a fully heated room.
- Why it saves money: Minimal insulation, optional HVAC, and simpler construction.
- Great for: Lounging, dining, or playrooms—especially in spring through fall.
4. Divide an Existing Room
Extremely low cost
- Quick win: Add a wall or even just use bookshelves or sliding panels to create a new room.
- Perfect for: Home offices, kids’ rooms, or guest spaces when privacy is needed on a budget.