Love your neighborhood, but need more house?
Major home additions, second-story expansions and whole-home renovations-designed and built by one coordinated team. Explore design inspiration, learn how our team works and schedule a conversation about your home.
Family-operated · Serving Northern Virginia since 1987
Trusted by Northern Virginia homeowners.
"Their communication was amazing, they plan well, problem solve quickly"B. ChalkleyHome addition · Client testimonial
"Communication couldn't have been better. Outcome of project exceeded expectations."Kathleen M. HastingsClient testimonial
"They cleaned up every evening. Excellent communication, always on time."Ksenia PegueroRenovation · Houzz review
Make more of the home you already love.
We focus on substantial residential projects that change how a home looks, feels and functions.
Major Home Additions
Expand living areas, reconfigure the first floor or create room for a growing household.
Second-Story Additions
Add bedrooms, bathrooms or a new upper-level layout while staying in your neighborhood.
Whole-Home Renovations
Update circulation, functionality, natural light and finishes with a coordinated design-build plan.
Imagine what your home could become.
Explore six design ideas for the spaces and possibilities you may be considering. Illustrative concepts only-not photographs of completed K-One projects.
Transitional ExteriorExterior design inspiration
Kitchen & EntertainingKitchen renovation inspiration
Living SpacesLiving-room design inspiration
Indoor-Outdoor LivingOutdoor living inspiration
Spa-Inspired BathroomBathroom remodeling inspiration
Finished Basement & BarFinished-basement inspirationWhat clients have said about K-One.
More feedback from homeowners who have worked with K-One.
"The team did a great job of taking our feedback during the design process, and worked within our budget needs."Familia T.Public customer review · Design process
"We would choose this company again for future projects."TerryPublic customer review · In-law suite addition
"K-One does very good work! All of the details for the project were defined and followed."Gerald W.Public customer review · Project delivery
Meet Keyvan Moussavi.
Principal, K-One Design & Build · MBA, PMP
I work directly with homeowners to understand what they want to accomplish, what their property can accommodate and how to bring the design and construction process together.
K-One is a family-operated company serving Northern Virginia since 1987. Our design leadership includes Jina Moussavi, whose architectural education includes the Architectural Association in London. We coordinate design, engineering, permitting and construction as one team.
If you're considering a significant addition or renovation, I'd welcome an initial conversation about your goals.
Contact Us · Meet KeyvanWhat happens when we talk?
01 · Tell us your vision
We'll learn what isn't working, the type of addition or renovation you're considering, and your general timeline.
02 · Explore the possibilities
Discuss what may require evaluation: zoning, existing structure, feasibility, cost expectations and design approach.
03 · Define next steps
If there's a good fit, we'll explain how our team would approach the project's design and assessment.
Let's discuss your project.
Pick a time below to speak with Keyvan about your home addition, renovation or custom-home project. Your appointment is booked right here on this page.