How much do addition contractors typically cost?
- Seattle, Washington Average$54,207
- Typical Range$28,138 - $96,111
- Low End - High End$3,586 - $150,000
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Service Pros
TB
Federal Way, WA·
Bathroom Remodels, Kitchen Remodels
"They did a remodel of our laundry room and did an immaculate job! Worked closely with us on design suggestions and gave good feedback on materials and colors we were thinking and balanced our ideas with theirs. The work was very precise. They take great in the smallest detail and the work is of the highest quality!"
Dean C. in September 2024
GA
Gold Bar, WA·
General Construction
"I have been using their services for 10 years, and I greatly appreciate their integrity, trust, dedication, and the quality of their work. I would highly recommend them!"
Glenn B. in January 2021
Seattle, WA·
We can provide financing guidance for our valued customers., Design and Build, We design plans, drawings and submit for your permits, or we can work with your architect to take your project from concept to creation! , and 1 more
"Marybeth is excellent. Happy with the outcome."
brenda W. in August 2010
CC
Auburn, WA·
Exterior Decks, New or Replacement, Wood or Fiber-Cement Siding - New Construction or Replacement, Major Home Repairs (General Contractor) , and 7 more
"He was extremely reliable and did more that what was quoted, very nice to work with, and definitely knew what he was doing, and has very fair rates."
Brenda H. in June 2012
PG
Lynnwood, WA·
x
"Look in pictures for my review"
F88585294136A4F3A087AEBC947A6C7F176B9F5CB663617117059A61664EF8D6 5. in August 2025
WC
Snohomish, WA·
Handyman Services, Remodels
"They were professional and kept to a timely schedule. Really happy with how all the work turned out. Will be calling them for any future projects."
Amy W. in September 2024
KA
In business since 2017
Bonney Lake, WA·
Kitchen and Bath Remodels, Whole Home Renovations
About us: "With over 15 years of experence K A M Construction, Inc. takes great pride in our experience, expertise, quality and customer service that we provide to meet your needs. It is our mission to provide excellent workmanship and complete customer satisfaction from start to completion of a project. In order to understand the needs and expectations of our customers, we take great care to work and communicate with every customer in a professional manner. Our reputation is based on service, safety and quality, regardless of how large or small the job."
"Mauricio has over 30 years of experience and know many trades. He won't cut corners and will deliver high quality products. He's a professional and will work even with rain or snow."
1020E0F51C59096B6195D230C511AD2F2BDF8925F7119BDB5F4384BF32B2F5D9 8. in February 2026
Showing 10-17 of 17 results
Costs for related projects in Seattle, WA
- Build a Barn, Shed or Playhouse$335 - $3,071
- Build an Addition$28,138 - $96,111
- Demo an Interior$1,155 - $6,042
- Perform Home Renovations and Repairs$3,012 - $20,116
- Remodel or Renovate a House$18,867 - $77,849
Frequently asked questions
- It’s important that you verify their license is still in good standing. Also keep in mind that certain states or provinces don’t require licensing if the job is under a certain dollar amount.
- You can find a list of your state’s licensing requirements on the HomeAdvisor website. Before you get to work with the pro, make sure their qualifications are current and acceptable to you.
- It is always a good idea to get a copy of the pro’s insurance certificate for future records, and in case anything happens. This is a good way to feel more secure in your home project, and to weed out potential scammers.
HomeAdvisor makes it easy to connect with pros near you. You can read reviews, get quotes and book appointments all in one place.
Depending on the type of project, you may find subtle differences in the hiring process. Here’s a look at task-specific advice.
You can use HomeAdvisor to help evaluate a contractor’s qualifications. We put pros through a screening process, and award badges to high-performing contractors. You can find these badges on a pro’s HomeAdvisor profile, and sometimes, his or her website.
Your research doesn’t stop here. Once you’ve found a few prospective companies, make an call to ask a few questions about work history, licensure and more:
- Have you completed a job like this before?
- Do you have a list of references I can contact?
- When are you able to start the job?
In most cases, the responses you get to these three questions will give you a very good idea of the right pro for your project. If you have more than one front-runner, these additional questions can help you narrow it down.
- How many years of experience do you have?
- What’s your permanent business address?
- Are you licensed to work in my area?
- When did you earn your business license?
- How do you handle warranty service complaints?
- Do you have worker’s compensation, property damage and personal liability insurance?
Any good contractor will answer these questions, and most will appreciate dealing with a client that takes such an active interest in finding good service. On the other hand, if a contractor gives you a hard time with these questions, you probably want to find someone else.
Related Projects in Seattle, WA
HomeAdvisor Community Rating
Overall Rating:
Seattle Addition & Remodeling Contractors are rated 4.9 out of 5 based on 389 reviews of 389 pros.
The HomeAdvisor Community Rating is an overall rating based on verified reviews and feedback from our community of homeowners that have been connected with service professionals. See individual business pages for full, detailed reviews.
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Recent Job Requests for Addition & Remodeling Contractors in Seattle, WA
Project Location: Seattle, WA Date: 02/05/24Type of Addition: Ground level additionProject Description: Design and buildWhat types of rooms/spaces are you interested in adding to your home?: Bedroom(s)Comment: Customer did not provide additional comments. Please contact the customer to discuss the details of this project.Project Location: Seattle, WA Date: 02/03/24Type of Addition: Detached additionProject Description: Design and buildWhat types of rooms/spaces are you interested in adding to your home?: OtherComment: Purchasing a house on top of Queen Anne that needs a detached garage. Lot is 40 x 120 ft and there is a back alley. The house is 1980 sqft with a 730 sqft footprint. There is a 2 park gravel parking pad on the back alley side of the lot. I would like to build a 2 car garage with a concrete foundation on the existing parking pad within the limits of a Subject to field Inspection permit. Someday I may want to add a loft to the garage, so it would be ideal to build with this in mind. But for now I just need a place to store cars, motorcycle, bikes etc. and have some space for a workbench.Project Location: Seattle, WA Date: 02/02/24Type of Addition: Second story additionProject Description: Design and buildWhat types of rooms/spaces are you interested in adding to your home?: Living/family roomComment: Add onto house to make dinning/living room on main floor. Family room/bathroom on ground level. This house has a daylight basement.Project Location: Seattle, WA Date: 02/02/24Type of Addition: Second story additionProject Description: Design and buildWhat types of rooms/spaces are you interested in adding to your home?: Bathroom(s)Comment: I want to add a second story onto our 280 sq ft garage. Ideally it would be one large master bathroom.Project Location: Seattle, WA Date: 02/01/24Type of Addition: Ground level additionProject Description: Build - use existing architectural drawingsWhat types of rooms/spaces are you interested in adding to your home?: Bathroom(s)What types of rooms/spaces are you interested in adding to your home?: KitchenWhat types of rooms/spaces are you interested in adding to your home?: Living/family roomWhat types of rooms/spaces are you interested in adding to your home?: Bedroom(s)What types of rooms/spaces are you interested in adding to your home?: OtherComment: lot with permitted project ready to be built! Permits and plans included. Modern 2825 SF well-designed house. 3 bed, 3bath. Plus an additional 2bed, 1bath 810 SF ADU in Basement. Almost an acre property. 2 lots. Water meter on site. Power and Sewer in street for easy connection.Project Location: Seattle, WA Date: 02/01/24Type of Addition: Ground level additionProject Description: Build - use existing architectural drawingsWhat types of rooms/spaces are you interested in adding to your home?: Bedroom(s)Comment: Need additional bedroom with toilet n bathroom. Space is bigger than a typical bedroom so I thought there will be space for bath/toilet. This room will be adjacent to the kitchen n facing d backyard. Our house has 1 master bedroom, 3 additional bedrooms, 1 full bath- all bedrooms are upstairs. Downstairs has powder room, kitchen, living room, family room, dining room. Hope this helps. Thank youProject Location: Seattle, WA Date: 01/31/24Type of Addition: Second story additionProject Description: Build - use existing architectural drawingsWhat types of rooms/spaces are you interested in adding to your home?: Bathroom(s)What types of rooms/spaces are you interested in adding to your home?: Bedroom(s)Comment: Customer did not provide additional comments. Please contact the customer to discuss the details of this project.Project Location: Seattle, WA Date: 01/31/24Type of Addition: Second story additionProject Description: Design and buildWhat types of rooms/spaces are you interested in adding to your home?: Bathroom(s)What types of rooms/spaces are you interested in adding to your home?: OtherComment: Customer did not provide additional comments. Please contact the customer to discuss the details of this project.Project Location: Seattle, WA Date: 01/29/24Type of Addition: Convert or finish existing spaceProject Description: Design and buildWhat types of rooms/spaces are you interested in adding to your home?: Bathroom(s)Comment: I have a low ceiling basement that I would like to add a bathroom to. The likely location is where the water heater storage tank is located.Project Location: Seattle, WA Date: 01/29/24Desired Completion Date: Timing is flexibleRequest Stage: Planning & BudgetingProject Description: Design and buildComment: Customer did not provide additional comments. Please contact the customer to discuss the details of this project.Project Location: Seattle, WA Date: 01/26/24Type of Addition: Convert or finish existing spaceProject Description: Design and buildWhat types of rooms/spaces are you interested in adding to your home?: Bathroom(s)Comment: Adding two story additional room to the back of existing house.Project Location: Seattle, WA Date: 01/26/24Type of Addition: Second story additionProject Description: Build - use existing architectural drawingsWhat types of rooms/spaces are you interested in adding to your home?: Bathroom(s)What types of rooms/spaces are you interested in adding to your home?: KitchenWhat types of rooms/spaces are you interested in adding to your home?: Bedroom(s)Comment: Customer did not provide additional comments. Please contact the customer to discuss the details of this project.Project Location: Seattle, WA Date: 01/24/24Type of Addition: Second story additionProject Description: Build - use existing architectural drawingsWhat types of rooms/spaces are you interested in adding to your home?: Bathroom(s)What types of rooms/spaces are you interested in adding to your home?: Bedroom(s)Comment: I wish to add a modest bedroom and bath to a 1909 Bungalow. Stair would rise over existing stair between main and basement. Electric and plumbing have been updated. Bathroom would be added over main floor bath. Anticipate ~ 450 square feet total. I would like to handle interior paint and trim.Project Location: Seattle, WA Date: 01/24/24Type of Addition: Convert or finish existing spaceProject Description: Design and buildWhat types of rooms/spaces are you interested in adding to your home?: Bathroom(s)Comment: Basic need for plans & build: Looking to add a small three-quarter bathroom to a finished basement. I need help designing a space efficient plan to convert/reconfigure current laundry room into small bathroom with walk- in shower. I’d like to consider how to utilize the space under the basement stairs [leading to laundry room], which is currently an unfinished closet that houses the plumbing stack. Flexible on scope of project: Additionally, there is ground floor square footage on the back of the house, that could be of potential use if laundry/mudroom need to be relocated or added. A contractor with project design and local coding knowledge would be helpful, for possibly expanding the scope of the project. Or to plan with any future renovations in mind. Ideal collaboration: I’m looking to be cost effective and possibly reuse existing cabinets and possibly source discounted or salvaged materials. Anyone that is creative with parts and materials, would be ideal. Ideally, someone that can maximize function with limited space.Project Location: Seattle, WA Date: 01/24/24Desired Completion Date: Timing is flexibleProject Description: Design and buildRequest Stage: Planning & BudgetingComment: Customer did not provide additional comments. Please contact the customer to discuss the details of this project.Project Location: Seattle, WA Date: 01/22/24Type of Addition: Ground level additionProject Description: Build - use existing architectural drawingsWhat types of rooms/spaces are you interested in adding to your home?: Living/family roomComment: Looking to add about a 10x10 (100 sq ft) addition to my house. Two of four walls are already built and form the exterior of the home. Am interested in adding a deck for entertaining on top of the new addition. Am interested in ballpark costs to complete a project along these lines.Project Location: Seattle, WA Date: 01/21/24Type of Addition: Ground level additionProject Description: Design and buildWhat types of rooms/spaces are you interested in adding to your home?: Bathroom(s)What types of rooms/spaces are you interested in adding to your home?: Bedroom(s)Comment: Make the existed bedrooms become bigger and build one more bathroomProject Location: Seattle, WA Date: 01/20/24Type of Addition: Ground level additionProject Description: Design and buildWhat types of rooms/spaces are you interested in adding to your home?: Bathroom(s)What types of rooms/spaces are you interested in adding to your home?: KitchenWhat types of rooms/spaces are you interested in adding to your home?: Living/family roomWhat types of rooms/spaces are you interested in adding to your home?: Bedroom(s)Comment: Build Additional small House in the back of existing house .
