Build a Prefab Multifamily ADU in Castaic - Smart, Flexible, and Ready to Go

Make It

MF ADU makes creating a functional, modern ADU in Castaic simple and stress-free. Our Castaic Prefab ADUs and Multifamily ADUs in Castaic are pre-engineered and permit-ready, designed for local parcels including sloped lots, cul-de-sacs, and properties with septic systems.

From feasibility and site assessment to selections, permitting, and installation, we guide you through every step. Our managed process ensures your ADU is compliant, high-quality, and tailored to your property. Whether it’s for multigenerational living, rental income, or a private studio, your Castaic Multifamily ADU is ready to enhance space and value.

Why Castaic Residents Prefer MF ADU for Their ADUs

  • Smart Footprints – Preserve yard space, parking, and privacy from the main home while maximizing usable ADU area.

  • Transparent Pricing – Clear, documented inclusions and site-work allowances with no hidden surprises.

  • Guided Process – Done-with-you approach from feasibility and selections through permitting and installation.

  • Durable Finishes – Low-maintenance materials built for everyday family use or rental occupancy.

  • Utility Planning – Designed for longer utility runs, potential panel upgrades, and septic tie-ins when needed.

  • Popular Fits for Castaic Lots

    • Studios & 1-Bed ADUs – Perfect for guest suites, home offices, or caregiver space with minimal yard impact.

    • 2-Bed ADUs – Ideal for deeper parcels, supporting multigenerational living while keeping outdoor areas usable.

    • Drive-Aisle & Rear-Yard Placements – Window and door positions optimized for privacy, with layouts planned for longer utility routes.

Make It

Castaic permitting at a glance

ADUs are allowed on most single-family and many multifamily parcels, though rules are site-specific. Key factors include setbacks, height, lot coverage, utility locations, parking, and septic capacity where applicable. Parcels in Hillside or WUI (wildland-urban interface) areas may face additional requirements, and some neighborhoods have HOAs/CC&Rs affecting exterior design. Our feasibility review examines parcel data, overlays, utilities/septic, and identifies the most straightforward path to approvals. (General information only; final eligibility depends on your parcel and current city regulations.)

What the ADU Process Looks Like in Castaic

  1. Feasibility & Fit – Assess your parcel, driveway/access, slope, utilities, and septic to determine the best-fit Prefab ADU in Castaic or Multifamily ADU in Castaic.

  2. Selections & Scope – Confirm finishes, layout options, and site-work assumptions, aligning foundation and utility plans for your Castaic ADU.

  3. Permits & Approvals – Prepare a permit-ready package and coordinate with the city/county and any HOA requirements.

  4. Site Work & Installation – Complete foundation, trenching, delivery/assembly, interior finishes, and inspections for your Castaic Multifamily ADU.

  5. Handover – Conduct a walkthrough, provide documentation, and offer guidance for rental, guest, or multigenerational use.

Make It

Pricing & timelines

The total cost of a Prefab ADU in Castaic or Multifamily ADU in Castaic depends on model size, foundation type, distance to utilities, electrical panel capacity, access logistics, and any hillside/WUI or septic requirement

Did you know?

Many Castaic properties are ideal for a detached ADU with a private patio and entry, offering fully separate living space for family or tenants while preserving the main home’s curb appeal.

Nearby areas we serve

Val Verde • Stevenson Ranch • Valencia • Saugus • Canyon Country • Santa Clarita

Start your Castaic ADU

Ready to add flexible space or a long-term rental? Contact us to get a feasibility review and a clear plan for your property.

FAQs — Castaic

  • Often not—especially for parcels near transit or when replacing existing spaces—but requirements are site-specific. We confirm parking needs during the feasibility review for your Castaic ADU.

  • Timelines depend on your ADU model, permitting process, and site work. After the feasibility review, we provide a clear, step-by-step schedule tailored to your Prefab ADU or Multifamily ADU in Castaic.

  • Yes! Many homeowners use Prefab ADUs or Multifamily ADUs in Castaic for long-term rentals or family housing. During handover, we provide guidance on best practices and local regulations to ensure compliant use.

  • Typical upgrades include electrical panel capacity checks, longer trenching runs for larger lots, and sewer or septic tie-ins. All necessary utility work is included in the scope of your Prefab ADU or Multifamily ADU in Castaic.

  • Feasibility identifies added steps—such as fire access, defensible space, grading details, or HOA design review—and whether your parcel can proceed.