House Plan Companies in Washington D.C.

“Transforming Architecture has been outstanding to work with! So much so that I’ve hired them twice, first for architecture and then for interior design, and would happily do it again. For the ADU, the plans were truly exceptional. They designed a light‑filled space with more windows than I imagined and even included a bonus/storage room upstairs that I hadn’t expected. The design far exceeded my expectations, and my builder commented that it was the best set of plans he’d ever seen. Transforming Architecture also handled the entire permitting process and patiently answered every question along the way (insulation, drywall, sprinkler systems, foundation/stem wall, and more). Sara C. was the lead on this project, and Karen, the principal, stayed involved throughout. I later brought them back for interior design, and Grace C. has been the project lead. They have now touched virtually every room in my home and we are still moving forward at my pace. Highlights include: restoring my office to a more private, original location; transforming the laundry room into a flexible “laundry salon” with mirrors and hair dryers; creating a vintage‑inspired 1970s formal living room with a record player and floor‑model television; refining the dining room; designing a nautical, globally inspired den with globes and a 50‑gallon aquarium; giving the foyer an upscale, beachy feel; updating the basement to a 2026, older‑kids‑friendly hangout with a game table and 85‑inch TV; turning the great room addition into a contemporary space with a cloud‑style sectional sofa and large television; and a peachy-pink mid-century model bathroom with gold and black matte finishes. What sets Transforming Architecture apart is that their design comes from a strong architectural perspective meaning their furniture placement, scale, and the relationships between pieces is precise and intentional, not random. The result is a home that feels beautifully cohesive, functional, and finally grown-up rather than transitional. Karen, Sara, and Grace are a pleasure to work with: professional, collaborative, and responsive. I highly recommend Transforming Architecture.”

“Did a fantastic job adding a 2nd full bathroom to a classic 100-year-old rowhouse. Very easy to work with, flexible and communicated well with the inevitable unexpected findings. Finished in the time they said and very transparent about costs throughout. Have already recommended them to multiple friends!”

“We are so lucky we found Lily. Working with Lily has been overall nothing short of an exceptional experience. We decided to do a large home project- we wanted to redo the deck and our basement. We knew this wasn't going to be easy. Such projects always go over budget and there are always arguments with contractors and vendors. We wanted to extend our deck and make the basement comfortable. We were not expecting this to be miraculous. But that is what Lily delivered. She incorporated a slide on our deck for our children. She designed a gorgeous deck that would allow the walk-out basement to have tons of light. She designed a basement that could comfortably house our entire family. All this and under budget. She took the time to understand what we wanted and she exceeded expectation. Lily's level of service is excellent. She will text back always and stop by often to check on the work. She will work with you to make sure that you are happy. We have enjoyed every step of this project. Her vendors are carefully selected and always competitive. I am amazed by her talent and eye for design. We whole heartedly recommend Lily Z Designs.”