Go Far®Phase 1: Design and engineering — 1 to 3 months
Every addition starts on paper: measuring the existing house, designing the new space, and getting structural engineering for foundations, beams, and the connection to the existing framing. Simple bump-outs move through design in weeks; a large addition or anything touching the roofline takes longer. This is also when the important budget decisions happen — our addition cost guide covers what those decisions are worth.
Phase 2: Permits — 6 to 12 weeks, city by city
Additions need full building permits everywhere we work, and review times vary by jurisdiction and season. A complete, well-prepared submittal commonly clears in 6–12 weeks across Snohomish and King County cities; incomplete applications bounce and start the clock again, which is the single most avoidable delay in the whole process. We prepare and track the application with the right permit office — and keep designing cabinets and finishes while the city reviews, so no calendar time is wasted.
Phase 3: Construction — 2 to 6 months by addition type
- Bump-outs and small single-room additions (under ~150 sq ft): roughly 6–10 weeks once foundation work starts.
- Mid-size additions — a family room, bedroom, or new bathroom in the 150–400 sq ft range: about 3–4 months.
- Large additions and primary suites (400+ sq ft, plumbing-heavy): typically 4–6 months.
- Second-story additions: the big one — 6–9 months of construction, with a choreographed roof-off stretch. Our second-story guide explains why.
The sequence inside those windows is consistent: excavation and foundation, framing, roof and weather-tight shell, rough plumbing/electrical/HVAC with inspections at each step, insulation and drywall, then finishes. The shell goes fast and feels dramatic; the systems-and-finishes half moves slower and is where quality is won.
What about the rain?
Less than most homeowners fear. Foundations and framing happen year-round in western Washington — crews here are built for it, and the house is protected before the existing wall is ever opened. The practical seasonal note: permit offices and contractor calendars are busiest in spring, so starting design in fall or winter often means breaking ground at the front of the good weather instead of the back of the queue.
What actually causes delays
Three things, in order: change orders (deciding mid-build to move a wall or upgrade a window package), long-lead materials (custom windows and doors can run 8–12 weeks — ordered late, they stall a weather-tight house), and incomplete permit submittals. All three are process problems, not luck — which is why a detailed plan and an itemized, decided-up-front scope is the best schedule insurance there is.
Get a schedule for your project
Go Far Construction builds additions across Lynnwood, Seattle, and Snohomish & King County with owners on site and phases inspected as we go. A free estimate comes with an itemized price and a realistic phase-by-phase schedule for your specific project — so you know not just what it costs, but when you get your house back.