Portland Home Additions
Your family has grown, your needs have changed, and your home hasn't kept up. A home addition gives you the space you need without the cost and stress of moving. At Crestwood Property Services, we handle every phase of your addition from architectural design through final walkthrough. One team, one point of contact, and a finished space that looks like it was always part of the house.
Home Additions for Every Need and Budget
Whether you need a single room or a full second story, we design and build additions that expand your home and your possibilities.
Room Additions
$80,000 - $175,000
Single-room expansions that add the space you need most. A new bedroom, a home office with real walls and a door, or a family room that finally fits the whole family. These additions extend your home's footprint with minimal disruption to the existing layout.
- Bedroom additions
- Home office builds
- Family room expansions
- Sunroom additions
- Bump-out extensions
- Garage conversions
Primary Suite & Multi-Room Additions
$175,000 - $350,000
Larger additions that include bathrooms, walk-in closets, and connected living spaces. Primary suite additions are the most requested project we build. These require careful integration with your home's existing plumbing, electrical, and HVAC systems.
- Primary suite with bathroom
- In-law suite additions
- Kitchen expansions
- Multi-room floor plan additions
- Bathroom & laundry additions
- Mudroom & entry additions
Second Story & Custom Additions
$350,000 - $500,000+
When your lot doesn't allow for outward expansion, building up is the answer. Second story additions can double your living space without reducing your yard. These projects require structural engineering and careful design to maintain your home's character.
- Full second story additions
- Partial second story builds
- Structural reinforcement
- Custom architectural design
- Foundation upgrades
- Full MEP system integration
Complete Addition Services from Foundation to Finish
Architectural Design & Permits
Every addition starts with a plan that works structurally and passes permitting. We coordinate architectural drawings, structural engineering, and the full permit process with the City of Portland Bureau of Development Services. You get a buildable design that meets code before we break ground.
Foundation & Structural Work
A solid addition starts below grade. We handle excavation, concrete footings, foundation walls, and any structural reinforcement your existing home needs to support the new space. For second story additions, we assess load paths and reinforce framing as required.
Framing & Exterior Shell
The frame goes up, the roof ties in, and the exterior gets sealed. We match your existing roofline, siding, and trim so the addition looks original to the house. Portland's rain demands proper flashing and weather barriers at every connection point.
Electrical, Plumbing & HVAC
New rooms need new systems. We run electrical circuits, plumbing lines, and HVAC ductwork to the addition and tie them into your existing infrastructure. For suites and kitchens, this includes dedicated circuits, water supply, drainage, and climate control.
Interior Finishing
Drywall, paint, trim, flooring, and fixtures bring your addition to life. We handle every interior finish from insulation through final paint touch-ups. As a full-service home improvement company, we do this work in-house rather than farming it out to subcontractors.
Roofline Integration
The roofline is what makes or breaks an addition's appearance from the street. We design roof connections that match your existing pitch, material, and style. Proper integration means no visible seam between old and new from the outside.
From First Sketch to Move-In Day
One team manages your addition from design through construction. No hand-offs between architects and builders, no miscommunication between trades.
We visit your home to discuss what you need, assess your lot and existing structure, and talk through what's feasible. We'll cover zoning setbacks, structural considerations, and realistic budgets before any commitment.
We develop floor plans and elevations that maximize your new space while respecting your home's character. Structural engineering confirms the design is buildable. You review and approve the plans before we submit for permits.
We handle the full permit process with the City of Portland. This includes plan review, structural review, and any required design review or neighborhood notifications. Permitting timelines vary, and we keep you updated throughout.
Construction begins with site preparation, excavation, and foundation work. Once the foundation cures, framing goes up. You'll see your addition take shape quickly during this phase. We coordinate inspections at every stage.
Electrical, plumbing, and HVAC rough-ins happen before the walls close. The roof goes on, siding gets installed, and the addition is sealed from weather. Insulation goes in once all systems pass inspection.
Drywall, paint, flooring, trim, fixtures, and final connections bring the space to life. We finish with a detailed walkthrough where you inspect every element. Your addition isn't complete until you sign off on the results.
Timeline Estimates: Bump-out addition: 2-3 months | Primary suite addition: 4-6 months | Second story addition: 5-8 months
The Crestwood Difference
Design-Build Under One Roof
We handle design, engineering, permitting, and construction as one team. No juggling architects, engineers, and separate contractors. One company, one schedule, one point of accountability from first sketch to final walkthrough.
Owner on Every Project
The owner of Crestwood is involved from your first consultation through construction. You always have a direct line to the person responsible for the quality of your addition.
Fixed Pricing
Our proposals include everything—design, permits, materials, labor, and finishing. The price we quote is the price you pay. No surprise change orders when we open a wall and find old framing that needs reinforcement.
In-House Crew
Our construction crew works for us, not a subcontractor pulled from a list. That means consistent quality, proper technique, and a team that knows our standards and shows up on schedule.
Portland Home Expertise
We know Portland homes. Craftsman bungalows with balloon framing, mid-century ranches on hillside lots, foursquares with limited setbacks. Different homes present different challenges, and we've worked on all of them.
Industry Leading Warranty
We back our addition work with a comprehensive workmanship warranty. Structural connections, exterior weatherproofing, interior finishes—if our work fails, we fix it.
What Portland Homeowners Say
We needed a primary suite on the main floor so we could age in place. Crestwood designed an addition that matched our 1940s home perfectly. The roofline ties in seamlessly and our neighbors thought the room was always there. The whole project came in on budget.
Our family outgrew our two-bedroom bungalow, but we didn't want to leave Sellwood. Crestwood added a second story with two bedrooms and a full bath. They reinforced the existing structure, matched the original siding, and finished ahead of schedule.
We converted our attached garage into a home office and guest suite. Crestwood handled the design, permits, insulation, electrical, and all the finishing. The space is comfortable year-round and looks like it was built with the rest of the house.
Home Additions Throughout Portland Metro
Portland Neighborhoods
- Alameda & Beaumont-Wilshire
- Laurelhurst & Eastmoreland
- Pearl District & Northwest
- Sellwood & Woodstock
- Alberta Arts & Irvington
- Hillsdale & Southwest
Surrounding Communities
- Beaverton
- Tigard
- Lake Oswego
- West Linn
- Tualatin
- Sherwood
- Hillsboro
- Gresham
- Oregon City
Frequently Asked Questions
How much does a home addition cost in Portland?
Home addition costs in Portland vary widely based on size, complexity, and finishes. A single-room addition typically runs $80,000 to $175,000. Primary suite and multi-room additions range from $175,000 to $350,000. Second story additions and custom projects start around $350,000 and can exceed $500,000. We provide detailed fixed-price proposals after an in-home consultation.
How long does a home addition take to build?
Most home additions take 4 to 8 months from design through completion. Permitting with the City of Portland can take several weeks to a few months depending on project complexity. Construction timelines depend on the size and scope—a bump-out addition may take 6 to 8 weeks of construction, while a second story addition typically takes 3 to 5 months. We provide specific timelines during the design phase.
Do I need a permit for a home addition in Portland?
Yes. Any structural addition in Portland requires building permits from the Bureau of Development Services. This includes plan review, structural review, and inspections during construction. Some projects also require design review or neighbor notification depending on your zoning overlay. We handle the full permitting process.
Is it cheaper to build out or build up?
Building out (ground-level addition) is often less expensive because it avoids structural reinforcement of existing walls and framing. However, it requires adequate lot space and setback compliance. Building up (second story) avoids expanding your footprint but needs significant structural work to support the added weight. The best option depends on your lot, foundation, and zoning constraints.
Can I live in my home during the addition?
In most cases, yes. For additions that expand outward, you can typically stay in your home throughout construction. For second story additions or projects that affect core living areas like the kitchen, we may recommend temporary relocation for a portion of the project. We discuss logistics during the design phase so you can plan ahead.
Will the addition match my existing home?
That's the goal and one of our highest priorities. We match rooflines, siding, trim profiles, window styles, and interior finishes so the addition looks original. Portland homes span a wide range of styles—Craftsman, mid-century, colonial, contemporary—and we design specifically to complement your home's architecture.
What's the difference between a home addition and an ADU?
A home addition expands your existing home and shares its living space, utilities, and systems. An ADU (accessory dwelling unit) is a separate, self-contained unit with its own kitchen, bathroom, and entrance. Portland has specific zoning rules for each. If you're unsure which option fits your needs, we can discuss both during your consultation.
Do home additions increase property value?
Well-designed additions typically increase property value, especially when adding bedrooms, bathrooms, or expanding kitchens. The return depends on your neighborhood, the quality of the work, and how well the addition integrates with the existing home. Additions that look like afterthoughts reduce curb appeal, which is why seamless design matters.
Ready to Add Space to Your Home?
Tell us about your project. We'll visit your home, assess what's possible, and give you a fixed-price proposal with a clear timeline—no obligation, no pressure.
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