ADU & Addition Design
in Santa Rosa & Sonoma County
Whether you're adding a detached accessory dwelling unit, expanding your primary home, or reimagining an underused space, an addition is one of the biggest investments you'll make in your property. At Humanity Design Works, we handle the full scope of ADU and addition projects, from structural design and permit drawings through interior design and material selection, so every phase of the project reflects one cohesive vision.
What We Design
ADU design, from initial concept through permit-ready construction drawings
Home additions, including room expansions, second-story additions, and structural reconfigurations
Interior design and space planning for the new space, integrated with your existing home
Material and finish selection, coordinated with your home's overall style
Permit-ready drawings prepared to meet your local jurisdiction's requirements
Our Process
Initial Consultation
We walk the property, discuss your goals for the new space, and review what may be possible based on the existing home and site.Concept & Space Planning
Our team develops the layout and overall design direction, balancing function, aesthetics, budget and buildability.Drafting & Design Development
Our drafter develops the drawings while our design team works through the interior design, cabinetry, materials, fixtures and finishes so the project is planned as one cohesive whole.Engineering & Permit Coordination
When structural engineering or other specialized services are required, we work closely with trusted engineers and other professionals to coordinate the information needed for permitting and construction.Construction Support
We stay involved throughout the build, working with the contractor and project team to answer design questions, coordinate selections and help keep the finished space aligned with the original design.
Why Homeowners Choose Humanity Design Works
An addition or ADU involves much more than simply creating a new room. It requires thoughtful planning, accurate drawings, engineering coordination, interior design and countless material and construction decisions. Humanity Design Works brings those pieces together from the beginning. Our team develops the design and drawings in house and works closely with engineers, contractors and other professionals as needed, helping create a project that is coordinated from concept through construction.
Featured Project
From the ground up, this detached ADU came together in stages, framed construction, a covered porch entry, and a bright, functional kitchen with clean white cabinetry and a full appliance suite. A great example of what's possible when a backyard structure is designed with the same care as the main house.
Ready to Start Your ADU or Addition?
If you're planning an ADU, addition, or expansion in Sonoma, Marin, or Napa County, we'd love to talk through your project. Schedule a Consultation to get started.