Backyard living, built to main-home standards.
A detached ADU is a real building — foundation, envelope, systems, finishes — just scaled down. JMB Builders brings the same pre-construction planning and construction management we apply to full homes, so your guest house or backyard unit is permitted, coordinated, and built to last.
Representative imagery — not a completed JMB project.
- Altadena homeowners adding a guest house or backyard unit for family
- Owners planning a rental ADU who want it built and documented like a main residence
- Families creating space for multigenerational living on their existing lot
- Anyone who wants a builder involved before the ADU plans are finalized
Planning
- Site and access review for backyard and hillside lots
- Constructability input alongside your architect or designer
- Utility and connection strategy for water, power, and sewer/septic
- Budget framing for the full scope — not just the visible finishes
Coordination
- Collaboration with your design team through plan development
- Permit-support coordination with the design team
- Long-lead material identification (windows, doors, systems)
- Sequencing that protects your existing home and landscaping
Construction & delivery
- Foundation, framing, envelope, and systems managed as one build
- Jobsite safety and neighbor-aware site management
- Quality control at each stage of the sequence
- Final walkthrough, documentation, and closeout
What an ADU project requires
- A lot with a realistic building envelope and access for construction
- Owner readiness for a design process before construction begins
- A budget shaped for a complete, permitted structure
- Patience with the permitting timeline — it depends on the jurisdiction and the plan
Initial Conversation
We talk about the project type, your property, desired outcomes, and where you are in the process. This is where fit is established—honestly, in both directions.
Discovery & Feasibility
We review existing conditions, clarify project goals, and surface early constraints—before anyone commits to a path.
Pre-Construction Planning
Scope alignment, budget strategy, and coordination with your architect and consultants. The most valuable stage of any major project happens before construction begins.
Design, permitting, and construction each take their own time, and every lot is different. Once we understand your property and the unit you have in mind, we can frame a realistic range during the first conversation.
We coordinate permitting support with your design team — the plans and approvals run through them with our constructability input. We never promise permit timelines; they depend on the jurisdiction and the plan.
In many cases, yes — Altadena and LA County rules govern what is allowed. We build the structure; your design team and the county determine the rental use that applies to your lot.
Our ADU work focuses on detached new construction, where full pre-construction planning adds the most value. If a conversion is part of a larger whole-home project, that can fit within that scope.
Complete Rebuilds
A clear path forward for properties requiring a full reconstruction..
Explore Complete RebuildsWhole-Home Renovations
Transformative renovations with the planning and coordination major work demands..
Explore Whole-Home RenovationsDiscuss an ADU
Tell us about your Altadena property, project scope, and timing. We’ll respond personally to discuss whether we’re the right fit.
