Koeppen Construction
Fall In Love
With Your Home Again!
Is your home tired, outdated, or just too small? With home prices through the roof and inventory low, trust Koeppen Construction with your dream and we will help you remember why you first fell in love with your home.
Koeppen Construction is a premier team of home remodeling contractors serving Longmont, CO, Boulder, CO, and the surrounding areas. Our expertise spans various areas, including kitchen remodeling, basement finishing, home additions, accessory dwelling units, garage additions, in-law suite additions, and basement remodeling.
Whether your home feels outdated or does not function for your family, Koeppen Construction is here to help. As trusted home remodel contractors, we breathe new life into your home, making it a place you once again love to be.
Update Your Cooking and Dining Area with Kitchen Remodeling
Our team is skilled at transforming kitchens into functional and beautiful spaces. We offer comprehensive kitchen remodeling services, from updating plumbing fixtures to installing new cabinetry and appliances. We work closely with you to create a kitchen that meets your unique needs and reflects your style.
Add Function with a Finished Basement
Basement finishing is one of our residential remodel specialties. We turn your basement into a functional space that meets your family’s needs and increases the value of your home. Whether you need a man cave, an entertainment area, or extra bedrooms, our expert team can deliver a basement remodel that exceeds your expectations.
We also excel in home additions. Whether you want to add a bedroom, create a luxurious master suite, or build a sunroom to enjoy the abundant Colorado sunshine, we are here for you.
Our home addition services also include the construction of accessory dwelling units. Often referred to as mother-in-law suite additions, backyard cottages, garage additions, or basement apartments, these additions enhance your living space, increase your home’s value, and provide the extra space you need for your growing family or changing lifestyle.
As the leading residential remodeling contractors near me, we are fully licensed and insured. We guarantee your satisfaction by ensuring excellent communication, value-driven pricing, and delivering a final product that aligns with your vision.
Contact Koeppen Construction today at (720) 378-7660 for all your home remodeling needs in Longmont, CO, and Boulder, Erie, Firestone, Frederick, Lafayette, and Louisville, CO.
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What We Offer
Basement Finishes
Growing family? Need a man cave? Finishing your basement is the most economical way to meet the needs of your family while increasing the value of your home.
Kitchen Remodels
Need to increase your kitchen capacity for hospitality? Breath life back into the heart of your home with new cabinetry, updated plumbing fixtures, and appliances.
Home
Additions
Pop the top, or blow out that wall to add a bedroom or create that master suite you’ve always dreamed of. Take advantage of Colorado’s 300 days of sunshine in a new sunroom!
Major Renovations
Tired of the bright gold fixtures, tile countertops, and that wall blocking your view to the living room? Maximize your investment by updating multiple rooms at the same time.
Accessory Dwelling Units
Often called mother-in-law suites, backyard cottages, garage, or basement apartments, these areas add to your functional living space and increase the value of your home.
Frequently Asked Questions
At Koeppen Construction, timelines vary with project size, but a mid-sized home renovation often spans 6–12 weeks depending on complexity, planning, and scope.
Yes—Koeppen Construction can accommodate residents during many renovations, but for extensive work (e.g., structural changes or full-floor remodels) temporary relocation may be advisable.
Koeppen Construction brings years of local experience in Longmont and Boulder, a focus on communication, quality workmanship, and a transparent process that puts homeowners first.
Yes—we offer full-service design and build solutions, seamlessly integrating architecture, layout planning and construction for a cohesive remodel.
Finishing your basement with Koeppen Construction adds usable living space, increases home value, and improves functionality—whether for a guest suite, office or family recreation area.
Koeppen Construction employs detailed scopes, transparent pricing, proactive change-management and regular budget reviews to help your project remain on track financially.
Absolutely—we include moisture-resistant materials, proper insulation and waterproofing as part of their basement finishing services to ensure durability and comfort.
With Koeppen Construction, the team studies your home’s architecture, materials and aesthetic and designs the addition to seamlessly integrate, preserving curb appeal and harmony.
Yes—Koeppen Construction confirms local building codes and handles permit requirements in Longmont (and surrounding areas) so your home addition is compliant and secure.
At Koeppen Construction, you can choose from second-story additions, bump-out expansions, sunrooms, mudrooms, in-law suites/ADUs, garage additions and more—all tailored to your goals and home.
Testimonials
Brian Cox17 July 2025Koeppen construction did a remodel of our basement and partial remodel of our kitchen. We were extremely impressed with the level of professionalism and knowledge, the quality of contractors and subtractors and especially their integrity, transparency and communication. Graham's team from the office staff to the site supervisor and carpenter's are excellent at their jobs and genuinely care about clear communication, attention to detail and problem-solving. Graham and Joe did an excellent job of listening to what we wanted but also provided intelligent, practical suggestions that were extremely valuable. Because Koeppen has worked for a long time in this community they have developed excellent resources for subcontracting or finding suppliers at competitive prices and understand how to navigate through the permitting process. In my experiences, all construction projects will encounter unexpected obstacles - the reason to hire qualified professionals is that they can successfully problem-solve and adapt or figure out work arounds. Koeppen handled every issue that arose and stood by their work. Highly recommend. Brian Cox
Jennifer Fick28 October 2024I highly recommend Koeppen Construction! We did a complete remodel of the entire first floor of our home and are very pleased with the results. Graham and his team were very responsive and have excellent attention to detail. We will definitely use them again when we are ready to remodel our second floor.
Melissa Swan16 October 2024We could not be happier with our basement! From start to finish we felt confident our vision was going to be made into a reality. During the build the team offered suggestions for a more professional finish that we hadn’t thought of, even if it meant more work for them. With any type of construction, obstacles will pop up. This team took the time to discuss and find a resolution that matched the quality of the rest of the project instead of just throwing together the “easiest” fix. I am very thorough person when paying attention to details. It was communicated in the beginning the extreme importance I was placing on a cohesive aesthetic. I wanted to match construction in a space 18 years after original construction. I did not want my project to look like an afterthought. GJKoppen absolutely accomplished that -which was not an easy feat! A great amount of time and effort was made in researching fixtures and finishes as well as tracking down obscure items that had been discontinued. We receive raving compliments on the workmanship from anyone who sees the space. This team genuinely cares about making their clients happy which seems rare these days. It is obvious they take pride in their work and it shows in the final product. They are all gems and we could not have made a better choice.
Brenda and Bob Taylor9 October 2024We just finished a major kitchen remodel with Koeppen Construction. Our dark, small, dated 1970s kitchen was transformed into a bright, beautiful and open kitchen. The remodel also included surrounding areas - a bathroom, a laundry area and a front room. Graham Koeppen created a wonderful design for our space. He thought of things we would never have thought of and as a result, we have a kitchen that I am excited to cook in and to share with family and friends. We were very impressed with all of the workers who worked on this project! They were all very skilled, punctual, respectful and cleaned up every day! Even the subcontractors that Koeppen used were great to work with. We also appreciated the communication throughout the whole process. Our project manager, Joe, was great! Many times he stayed later or came in extra to work on something that needed attention. He always took care of any concerns I had! And Niki was truly awesome! She always followed up with me or whoever was needed to remedy any issue at hand. She was quick to address my concerns and to answer my "silly" questions! I appreciate her "holding my hand" throughout this whole process, as I had never been through a remodel before! We will continue to recommend Koeppen Construction to our friends. Thank you to all who had a part in creating our dream kitchen. It far exceeded our expectations! Brenda and Bob Taylor
Dave Sehnert8 April 2022I have hired GJ Koeppen for three major projects and a couple small projects over the last 4 years. The attention to detail, responsiveness to issues as they (inevitably) arise and collaborative approach to resolving challenges are remarkable. My wife and children always felt comfortable with the team members in our home and they leave a clean workspace at the end of the day. I highly recommend GJK for any of your home improvement projects!
Calvin Coursey2 October 2021They do quality work in a short time will recommend to all looking for remodeling contractors...
Rick Mansfield8 May 2020We ended up accepting the bid of another contractor whose schedule better fit our need for a quick turnaround, so we can't speak to the overall renovation experience, but Graham impressed us with his professionalism throughout a somewhat complicated bid process. He asked incisive questions about what we wanted and suggested alternatives where appropriate during the initial consultation at the house. His bids were carefully itemized to facilitate comparison with other bids, and both his original bid and his update (when we changed what we requested) were fair. He was transparent about his schedule and didn't make promises he couldn't deliver. And he was patient as we agonized over our decision, and accepted with grace our final decision to go with another bid. I wouldn't hesitate to recommend Graham to others in need of contracting services.
Laura W22 April 2019We were HIGHLY impressed with GJ Koeppen from start to finish on a basement build-out to mother in-law apartment. Work was done on time, project came in on budget, their crew is friendly and professional, and the quality of the work is excellent. Any project will have a few minor snags; they responded and resolved those issues quickly and to our satisfaction. They stayed very communicative and transparent through all stages: from bid to administration/change orders (increased costs due to OUR changes/requests for preferred finishes) through actual work we were very impressed with all of their staff. We wouldn't hesitate to use them again on future projects, and have already recommended them to friends.