ADU Construction Services by ConstruBay in Marin County
ConstruBay is a design-build ADU contractor serving Marin County, California. They handle accessory dwelling unit projects from initial site visit through to move-in, operating as a single team across the entire process. Their service area covers Mill Valley, San Rafael, Tiburon, Novato, and all 11 jurisdictions within Marin County.
As an ADU builder, ConstruBay manages the full scope of a project — design, permitting, and construction — under one roof. This integrated approach is intended to reduce the coordination burden on homeowners and keep projects moving through each phase without handoffs between separate firms.
ConstruBay holds CSLB license #1106798 and is licensed, bonded, and insured. They take on a limited number of ADU projects per quarter, which they state allows each client to receive direct, personal attention throughout the build.
AI-Accelerated Permit Planning
One notable aspect of ConstruBay's process is their use of PlanPass.ai, an AI-powered construction permit intelligence platform. This tool is integrated into their workflow to help accelerate permit approvals across all 11 Marin County jurisdictions.
The platform is designed to:
- Flag potential issues before permit submission
- Provide clients with real-time visibility into their permit status
- Apply Marin-specific code intelligence to reduce back-and-forth with local agencies
According to ConstruBay, this approach results in permit approvals that are approximately 40% faster than the Marin County average. Pre-submission issue detection is a key part of this — identifying problems on a given lot before they become costly rejections or redesigns mid-project.
What to Expect When Working with ConstruBay
ConstruBay offers a complimentary site assessment as the starting point for prospective clients. This initial visit allows them to evaluate the property, identify any site-specific constraints such as setbacks or zoning considerations, and provide guidance before any commitment is made.
As a detached ADU builder and general accessory dwelling unit contractor in Marin County, their work includes navigating the varied requirements across different local jurisdictions — something that can be a significant challenge in a county with 11 separate permitting authorities.
Their project portfolio includes 150+ completed projects, and they maintain a 4.9-star rating on Google across 47 reviews at the time of writing.
For homeowners in Marin County considering an accessory dwelling unit — whether a detached ADU, a backyard cottage, or another configuration — ConstruBay positions itself as a locally focused contractor with a structured, technology-assisted process from site evaluation through to completed construction.