Our guide equips you with the working tools and knowledge. Our optional add-on services do the work. Every engagement is backed by 15+ years of California ADU expertise.
Not ready for full-service construction? Get direct access to senior staff and the Cornerstone Capital team — session by session, phase by phase, or hour by hour.
Includes live session (Zoom or phone) and follow-up summary notes.
Book a Single Session →Great ADU design balances aesthetics, function, agency code requirements, and your family's unique needs. Our design team focuses exclusively on residential ADU design and urban fit across California.
Our permitting team is led by a former city planner with deep inside knowledge of California jurisdictions. We've filed permits in 30+ cities and counties.
Most permit delays and denials stem from incomplete submittals, missed nuances in local code, or poor communication with agency permit clerks and city planners. Our team handles every step — and we communicate transparently with clients throughout the entitlement process.
As your Construction Manager and Owner Representative, we act exclusively in your interest — coordinating licensed contractors, enforcing quality standards, and maintaining full visibility into how your resources are applied.
Construction is where many homeowners get burned — cost overruns, poor-quality work, disappearing contractors. We exist to be the antidote to that. Our milestone-tracking means you always know where your money is and what's been accomplished.
A wise person counts the cost before building — and our Land Use Consulting service is your blueprint for doing exactly that. We analyze your specific parcel and deliver a written feasibility report so you can make informed, confident decisions.
We cover recent law changes (AB 68, SB 9, AB 2221) that have dramatically expanded ADU rights across California — rights many homeowners don't even know they have. We believe you deserve complete information, presented honestly, with no hidden agenda.
A dedicated project manager is your single point of contact from day one to final inspection. We coordinate all trades, manage schedules, and keep you fully informed at every milestone — no chasing contractors, no mystery charges.
Effective project management means managing resources — time, money, and people — with skill and transparency. Our project managers are trained to hold every subcontractor to the same standard we hold ourselves to: do what you say, say what you do, and take responsibility when things don't go as planned.
As your licensed General Contractor and Owner Representative, Cornerstone Capital coordinates and oversees all trade contractors on your behalf — so every party on your project answers to someone who is solely accountable to you.
This is where our commitment to integrity becomes concrete and legally binding. All subcontractors are verified, licensed, and carry their own general liability insurance and workers' compensation coverage. Lien releases at every milestone. A comprehensive warranty. No handshake deals, no ambiguous agreements.
Because you deserve to know the full picture before committing. All estimated pricing includes design, permitting, and construction. A detailed fixed-price proposal follows your property assessment.
All pricing includes design, permitting, and construction. Figures are estimates pending property assessment.
A detailed fixed-price proposal is provided following a full site evaluation.