Add Flexible Living Space With a Custom-Built ADU
Detached backyard units, attached ADUs, junior ADUs, and garage conversions designed, permitted, and built to code for rental income, family, or guests.
ADU Building
A Second Home on the Lot You Already Own
ADU building gives Orange County homeowners a practical way to create more living space without buying a second property. An accessory dwelling unit can house aging parents, give adult children a place of their own, welcome visiting guests, or provide steady rental income that helps offset rising housing costs. Midcrest Construction builds ADUs for homeowners in Lake Forest, California and surrounding communities, including Irvine, Mission Viejo, Laguna Hills, and Rancho Santa Margarita. We build detached backyard units, attached ADUs, junior ADUs carved from existing space, and garage conversions that turn underused square footage into complete, comfortable homes. Each unit can include a full kitchen, bathroom, living area, and private entrance. Our team reviews your lot, setbacks, and utility connections, prepares plans and permit applications, and manages every trade from foundation to final inspection. Every ADU is completed to code with careful attention to detail and clear communication from the first site visit to move-in day.
✓ Detached backyard ADUs
✓ Attached ADUs and additions
✓ Junior ADUs within the home
✓ Garage conversions
✓ Permits and plan check support
✓ Utility and sewer connections
10+ Years Experience
Lake Forest, CA
Room for What Comes Next
Accessory Units Planned Around Your Lot and Your Goals
An ADU is a small home with big decisions behind it. Here is what shapes the way we plan and build each unit.
Lot Review Before Design
We study setbacks, easements, slopes, access paths, and where existing utilities run before drawing anything. Starting with what your lot allows prevents redesigns later and helps the unit sit comfortably beside your main home and yard.
Paperwork Managed for You
City requirements for ADUs vary across Orange County. We prepare drawings, submit applications, respond to plan check comments, and schedule each inspection, so the paperwork keeps moving while you focus on planning how the space will be used.
Small Footprint, Smart Layout
Every square foot matters in an accessory unit. Open living areas, efficient kitchens, generous storage, and well-placed windows make a compact ADU feel bright, roomy, and genuinely livable for tenants, relatives, or guests staying longer term.
Utilities Sized Correctly
New units often need upgraded electrical panels, separate meters, water lines, and sewer connections. Our team evaluates capacity early and coordinates every connection, preventing costly surprises once the foundation is poured and framing begins on site.
Design That Matches Your Home
Rooflines, siding, stucco, windows, and exterior colors are chosen to complement your main house. A well-matched ADU looks like a natural part of the property and helps protect curb appeal, neighborhood harmony, and long-term resale value.
Built for Comfortable Living
Insulation, quality windows, efficient heating and cooling, sound control, and durable finishes make the unit pleasant year-round. Whoever lives there enjoys a complete, private home rather than a converted space that feels temporary or unfinished.
Types of ADUs We Build
From backyard cottages to converted garages, these ADU options help homeowners in Lake Forest, California add flexible living space.
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Detached Backyard ADUs
Freestanding units are built in your backyard with their own kitchen, bathroom, entrance, and living area, offering maximum privacy for tenants, relatives, or guests while keeping your main home separate.
02
Attached ADUs
Units attached to the side or rear of your house use existing structure, framing, and utilities efficiently while still providing a fully separate entrance and a comfortable, private living space.
03
Junior ADUs
Smaller units are created within an existing bedroom or living area, adding a compact kitchenette and private entrance, giving homeowners an affordable way to house family or earn rental income.
04
Garage Conversions
Underused garages are transformed into finished living spaces with insulation, windows, flooring, plumbing, and electrical upgrades, creating a comfortable ADU without expanding the footprint of your existing property or yard.
05
Second-Story ADUs
Units built above detached garages make use of vertical space on tight lots, preserving yard area while delivering a private living space with its own stairs, kitchen, bathroom, and layout.
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Interior Finishes and Fixtures
Cabinetry, countertops, flooring, tile, lighting, and appliances are selected to suit your budget and purpose, whether the unit is a rental, a guesthouse, or a home for a loved one.
What Our Customers Say
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What Our Customers Say
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How it works
How Our ADU Building Process Works
Your ADU building project starts with a site visit to review your lot, measure available space, and discuss who will live in the unit. We outline the best ADU type for your property, prepare plans, and provide a detailed estimate. Once permits are approved, our team handles site work, foundation, framing, plumbing, electrical, inspections, and interior finishes, keeping you updated at every stage until the unit is ready for move-in.
Many homeowners combine an ADU with other improvements around the property. A new unit pairs well with exterior remodeling to refresh the main house, and some families also add space through home additions or modernize the existing home with kitchen remodeling and bathroom remodeling. Professional plumbing services support every new water and sewer connection. Midcrest Construction serves Lake Forest, California and surrounding Orange County communities. Contact our team today to schedule a site visit and start planning your ADU.
Common questions
Frequently Asked Questions
Planning an accessory unit raises practical questions. These answers help homeowners in Lake Forest, California move forward with confidence.
How long does it take to build an ADU?
Garage conversions often take a few months, while detached ADUs typically take longer once design, permits, and construction are combined. City plan check times, utility work, and material lead times all affect the schedule we outline upfront.
Can an ADU have its own address and utility meters?
Many cities allow a separate address, and some homeowners choose separate electric or water meters for rentals. Requirements and connection fees vary by city and utility provider, so we confirm the options during early planning and design.
Do I need to live on the property to rent out an ADU?
California law currently does not require owner occupancy for most standard ADUs, though junior ADUs typically do. Local rules and HOA guidelines can still apply, so we review requirements for your specific property before construction begins.
Will building an ADU raise my property taxes?
Usually, only the value of the new unit is added to your assessment, while your existing home keeps its current assessed value. The county assessor determines the final amount, so asking them for an estimate during planning is wise.
What size ADU can fit in my backyard?
The size depends on your lot, setbacks, existing structures, and local rules. Many detached units range from studios to two-bedroom layouts. Measuring your yard and reviewing city standards helps us recommend a realistic, comfortable size and layout.
Is a garage conversion cheaper than a detached ADU?
Often, yes. A conversion reuses an existing foundation, walls, and roof, which can reduce construction costs. Replacing lost parking, upgrading insulation, and adding plumbing still require planning, so we compare both options for your property.