24+ years in operation
Established in 2002. Coastline has delivered projects across Southern California through changing markets, codes, and expectations.
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Coastline Custom Homes
Custom Home Additions
Expand living space with additions that feel original to the house — not bolted on.
Service Overview
What this service includes
A good addition matches structure, circulation, and finishes to what already works.
Coastline evaluates foundations, roof lines, and mechanical capacity before design locks.
Permits and neighbor impacts are planned with the same discipline as new construction.
Choose Coastline when you want the addition to read as one home when it is done.
- Typical project size
- $250K – $1.5M
- Typical duration
- 4 – 12 months
- Permit requirements
- Yes
Why Coastline
Why homeowners choose Coastline
Professional project management
Dedicated project managers, structured communication, and clear milestones from evaluation through completion.
Licensed & insured
California General Contractor License #813394. Fully licensed, bonded, and insured for your protection.
Documented process
Clear digital communication and documented milestones — without replacing the human relationship at the center of every build.
Our Process
From evaluation to completion
Evaluation
We review your project scope, site conditions, and goals before scheduling a site visit.
Planning
Design coordination, permits, selections, and a detailed scope aligned to your vision.
Pre-construction
Scheduling, site protection, material procurement, and mobilization before work begins.
Construction
Managed build with regular updates, inspections, and a dedicated project manager.
Completion
Final walkthrough, punch list resolution, and project handoff.
Project Gallery
Custom Home Additions in progress and completed
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Before & After
The transformation
Project Video
See the work
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FAQ
Frequently asked questions
That is the goal. We document existing materials and details so new work aligns.
Almost always in our markets. We confirm requirements during evaluation.
Often yes, with phasing. Dust control and temporary separations are planned per project.
Permits
Common permit information
Permit requirements for custom home additions vary by scope and jurisdiction. Coastline identifies requirements during evaluation. Typical permit level: Yes.
Permit assessment
We review your project scope against local building department requirements before construction begins.
Documentation & submission
Coastline prepares and submits permit applications and schedules required inspections.
Licensed execution
All work performed under California General Contractor License #813394.
Related Projects
Custom Home Additions projects
Whole Home
Laguna Beach Whole Home
Laguna Beach
Kitchen Remodel
Woodland Hills Kitchen
Woodland Hills
Service Areas
Southern California
Coastline serves homeowners across Southern California counties.
Smart Project Evaluation
Smart Project Evaluation
Share photos, plans, or a description of your project. A Coastline project manager reviews your submission and responds within one business day — no obligation.
Begin with a project evaluation
No obligation. Share your project details and a Coastline project manager will respond within one business day.
Request a Project EvaluationOr Contact Coastline · License #813394