A detached modern accessory dwelling unit (ADU) in a backyard

ADUs & additions in Valencia, Santa Clarita, CA

Serving homes and businesses across California

ADUs and home additions from MSH Development are for homeowners in Valencia, Santa Clarita, CA and across California. They include detached ADUs and guest houses, garage conversions and room additions, and plans, permits and inspections through final inspection. MSH holds CA License #1090148 (Class A & B), and the on-site estimate is free.

What's included

Backyard units, garage conversions and room additions, from plans to final inspection. MSH Development builds adus & additions projects across California, with a free on-site estimate within 48 hours.

Backyard ADUs, garage conversions and room additions managed from plans and permits through construction and final inspection.

Detached ADUs and guest houses
Garage conversions
Room additions
Plans, permits and inspections

Cost

What affects the cost of an ADU or addition

MSH Development does not publish a flat price for this, because the same job can cost very differently from one site to the next. ADUs and additions are priced from the plans. These factors matter most. Get a free estimate

Type of project

A detached ADU, a garage conversion and a room addition involve different amounts of structure, utilities and finishes.

Size and design

Square footage, kitchen and bathroom inclusion and the finish level.

Utilities and site

Connecting power, water and sewer, plus grading and access on the lot.

Plans and permits

Plans, permits and inspections from approval to final inspection are part of the work.

Finishes

Flooring, cabinets, fixtures and exterior finishes.

Questions

ADUs & additions: frequently asked questions

What kinds of projects do you handle?

Detached ADUs and guest houses, garage conversions and room additions, managed from plans and permits through construction and final inspection.

Do you handle plans and permits?

We manage the process from plans and permits through construction and final inspection.

How much does an ADU cost?

It depends on type, size, utilities and finishes. We give a written price after a free on-site estimate within 48 hours.

Who is the contractor?

MSH Development, a licensed California general contractor, CA License #1090148 (Class A and B).

Where do you build?

Mostly Santa Clarita, Valencia and the Santa Clarita Valley, plus the San Fernando Valley and Ventura County.

Gallery

ADUs & additions
gallery

The interior of a small modern ADU living area with a compact kitchenette along one wall in white cabinets with a quartz counter and a small sink

The exterior of a garage converted into an ADU

A small ADU bedroom with a neatly made bed in white linens, a light oak floor, white walls

A compact ADU bathroom with a frameless glass walk-in shower with white tile

A two-story detached garage with an ADU living space above

A small backyard cottage ADU in a modern farmhouse style with white board-and-batten siding

A wide backyard view showing a new detached ADU next to the main stucco house

An open-plan ADU interior with a vaulted ceiling with a white-painted wood beam

A small entry patio in front of a detached ADU, light gray and tan interlocking pavers

A small detached backyard ADU with white stucco walls

The interior of a compact ADU with a small modern kitchen along one wall with white shaker cabinets

A detached ADU with a covered entry patio under a simple wood-beam roof extension

A small ADU bathroom with a walk-in shower with a frameless glass panel and green zellige-style wall tile

More residential services

All residential remodeling services · See residential projects · Service areas

Ready to talk about
adus & additions?

Get a free estimate (310) 461-6515

ADUs & additions in Valencia, Santa Clarita, CA