We provide comprehensive structural engineering services for residential additions and remodels throughout Washington. Our engineers design safe, code-compliant solutions that meet local building department requirements in Seattle, Bellevue, Tacoma, and Spokane.
Structural Engineers for Home Additions & Remodels Permit-Ready Plans
Second-Story Additions
Add a full second story to maximize your property's potential. Our engineers design load-bearing systems, reinforce existing foundations, and ensure structural integrity for vertical expansions. Perfect for growing families needing more space without losing yard area.
Rear & Side Additions
Expand your living space horizontally with seamless additions. We handle foundation design, beam sizing, and lateral load analysis to integrate perfectly with your existing home. Great for adding master suites or expanding kitchens and living areas.
Room Additions
Add bedrooms, bathrooms, home offices, or living spaces. Complete structural engineering including foundation, framing, and roof integration to match your home's existing architecture. Increase both living space and property value.
Kitchen & Bathroom Remodels
Structural engineering for modern, open-concept renovations. We design solutions for load-bearing wall removals, creating flowing floor plans, new openings, beam installations, and reinforced floors for heavy fixtures like large kitchen islands and luxury soaking tubs.
Garage Conversions to Living Space
Transform your garage into livable space without major construction. Our engineers verify foundation capacity, design proper floor systems, and ensure code-compliant load paths for the conversion. Popular for home offices, gyms, or additional living quarters.
Whole House Remodels
Complete structural engineering for major home transformations. We handle foundation modifications, multiple wall removals, roof alterations, floor system reinforcement, and seismic retrofits. Perfect for modernizing older homes or complete redesigns while maintaining structural integrity.
Same-day quote • 2-3 weeks delivery • No hidden fees
Don't Have Plans or Architectural Drawings Yet?
No problem! We work with a network of trusted, design partners and licensed architects who can help you design your project from scratch. Once your design plans are ready, we'll handle all the structural engineering seamlessly.
What Our Clients Are Saying
See why homeowners and industry professionals across Washington trust us with their projects.
Trusted by homeowners and AEC industry professionals across Washington
Fast delivery • Permit guarantee* • Fixed Transparent Pricing
Built for Speed, Clarity, and Permit Success
Why Clients Choose ProStruct Engineering
2-3 Week Express Delivery
Don't wait months for plans. We deliver complete, permit-ready structural plans in just 2-3 weeks so you can start construction and enjoy your new space faster.
Permit Revision Guarantee*
If building departments have comments related to our scope of work*, we'll revise plans at no extra charge--no matter how many rounds it takes. We stand by our work until your permit is approved.
Transparent Pricing: Starting at $3,000
Projects start at $3,000 and vary based on size, complexity, and scope. No hidden fees. You'll receive a detailed quote within 24 hours.
Your Own Dedicated Project Manager
Every project includes a dedicated project manager at no additional cost. They act as your single point of contact, coordinating with our engineers and collaborating with third-party professionals--including architects, contractors, and others--on matters within our scope to ensure clear communication, faster decisions, and a seamless project experience.
Serving All Across Washington
We're the trusted structural engineers for home additions and remodels serving homeowners and AEC industry professionals throughout Seattle, Bellevue, Tacoma, Spokane, Vancouver, Olympia, and all surrounding Washington cities. Local expertise, fast service.