- hgarcia@hgdesignbuild.com
- (323) 317-4828
Southern California's Rated HGdb Contractor
Build Your
INVESTMENT PROPERTY in Southern California
Premium Architecture, Financial Models, and Turnkey Construction solutions tailored for retail investors. We don’t just build spaces; we craft lifestyles.
CSLB# 944871
Licensed & Insured
Score 139
Top 1% California Contractors
In-House
HGdb Financing Available
3 Counties
OC · LA County · Riverside
Who We Are
Redefining Spaces, Elevating Lives.
HGDB is more than a construction company — we are architects of transformation. Built on a foundation of integrity, craftsmanship, and attention to detail, we specialize in turning ordinary properties into exceptional living environments that elevate both form and function.
With years of expertise in multi-family development and architectural design, our team is committed to delivering projects that combine timeless aesthetics with practical, high-performing spaces. From the initial concept and feasibility analysis to the final paint touch-up, every phase of our work is guided by precision, quality, and a deep understanding of each client’s vision.
- Full design-build process — one team, no coordination friction
- Site planning and entitlement support
- Coordination of all inspections and regulatory approvals
- Financial analysis and rate-of-return evaluations for investment projects
At HGDB, we believe every project should not only improve a property but also create long-term value and a lasting impression.
Why The HGdb Pro®
Reasons We're Southern California's Best
Seamless Design-Build Integration
We provide a unified workflow by handling both design and construction under one roof.This eliminates the gap between the architect's vision and the builder's execution, ensuring a cohesive and stress-free experience for you.
Accelerated Project Timelines
Time is luxury. Our integrated approach allows us to fast-track your project, overlapping design and construction phases to deliver your dream home up to 33% faster than traditional methods without compromising quality
Guaranteed Cost Certainty
We provide realistic, transparent estimates early in the process. By managing the entire project, we minimize change orders and unexpected expenses, giving you total peace of mind regarding your investment.
Tailored Coastal & Modern Aesthetics
Navigating the regulatory landscape of SoCal (from LA to Orange County) can be a nightmare. Our team has the local expertise to handle complex zoning laws and permits efficiently, keeping your project on track.
Superior Craftsmanship & Materials
We don’t cut corners. We partner with the region's finest artisans and source premium materials to ensure that every finish, joint, and surface meets the highest standards of luxury and durability.
Future-Proof & Sustainable Building
We integrate eco-friendly materials and smart home technology into our builds. From energy-efficient HVAC systems to solar-ready designs, we build homes that are as intelligent as they are beautiful.
Why The HG Pro®
How Much Does a Backyard Unit Cost in Southern California?
Most Affordable
Garage Conversion / JADU
$85K – $150K
Up to 500 sq ft
- Converts existing attached garage
- Separate entrance required
- Efficiency kitchen + full bath
- Fastest permit approval
- From $280–$340/sq ft
⏱ Timeline: 4–5 months
Best Value
Detached ADU
$300K – $350K
Up to 1,200 sq ft
- 3 bed / 2 full bath floor plans
- Separate utilities
- Larger kitchen + laundry
- By-Right permit approval
- From $280–$310/sq ft
⏱ Timeline: 5-8 months
Maximum Open Space
2-Story Detached ADU
$310K – $360K
Up to 1,200 sq ft
- Upstair bedrooms
- Half bath downstairs
- Balcony deck option
- Tuck under parking option
- From $280–$320/sq f
⏱ Timeline: 5–8 months
Best & Highest Use
2-Story Detached ADU+SB9 Duplex
$590K – $670K
Up to 2,400 sq ft
- 2 backyard units
- Electrical service upgrade
- Townhouse or Stacked flats layout
- Exterior stair option
- From $250–$310/sq ft
⏱ Timeline: 4–8 months
What We Build
Four Types of ADUs We Specialize In
Discover the perfect accessory dwelling unit for your property. From standalone backyard cottages to budget-friendly garage conversions, we specialize in designing and building the four primary ADU styles
Most Popular
Detached ADU+SB9 duplex
- Upgraded electrical service - separate utility meters
- Maximize underutilized open space
- Coordination of all inspections and regulatory approvals
- Financial analysis and rate-of-return evaluations for investment projects
Our Work
Projects Across Southern California
Founder of HGDB, leveraging extensive architectural, construction, and development experience to
lead a residential general contracting firm with a focus on strategic project management and comprehensive analysis.
Park ADU
Huntington Park ADU
Huntington Park ADU
Corona, CA.
Pool Cabana
San Dimas
San Dimas, CA.
Interiors
Bell Gardens, CA.
Detached
Whittier, CA.
Colmar Ave
Claremont, CA.
Client Reviews
What Our Clients Are Saying
Every HG we build reflects our commitment to quality, innovation, and long-term client relationships.
Michelle T.
The HGDB Design transformed our backyard into a beautiful 750 sq ft guest house. DJ and his team were professional, always on time, and the quality is outstanding. Our property value increased significantly and we're generating passive income every month.
CH.Zohaib
The HGDB transformed our backyard into a beautiful 750 sq ft guest house. DJ and his team were professional, always on time, and the quality is outstanding. Our property value increased significantly and we're generating passive income every month.
T. Design
The HGDB transformed our backyard into a beautiful 750 sq ft guest house. DJ and his team were professional, always on time, and the quality is outstanding. Our property value increased significantly and we're generating passive income every month.
HGdb Financing
Financing Made Simple
The HGDB works with a network of trusted financial institutions and preferred lending partners who specialize in ADU construction loans — so you get competitive rates and a smooth process without shopping around on your own.
- Preferred Lender Network — We connect you with lenders who specialize in HG construction loans, HELOCs, and cash-out refinances — with competitive rates and HGDB-specific terms
- Multiple Loan Programs - Construction loans, HELOCs, cash-out refinances, and HGDB -specific state programs — we'll guide you to the right fit for your situation
- Your HGDB Can Pay for Itself - Rental income from $1,500–$4,000/month can cover your loan payment — many homeowners build with zero net out-of-pocket cost
Get Your Free HGDB Estimate
Common Questions
Questions, Answered
Everything homeowners in Orange County, LA County, and Riverside County need to know about building an HGDB.
Still have questions?
- Call : (323) 317-4828
- info@hgdesignbuild.com
- 15338 Central Ave., Chino CA 91710
- CSLB# 944871
Who is the best HGDB contractor in Orange County?
The HGDB® (CSLB #1128679) is the #1 rated ADU contractor in Orange County. Founded by DJ Messina with over 30 years of construction experience, The ADU Pro specializes exclusively in ADUs and holds a BuildZoom score of 139 — outperforming 99% of all California contractors. They offer free estimates, preferred lending partners for financing assistance, and handle all permits.
How much does it cost to build an HGDB in Southern California?
What counties does The HGDB serve?
Does The HGDB handle permits for HG construction?
How long does it take to build an HGDB in California?
Does The HGDB offer financing for HG construction?
Ready to Build Your Backyard Unit?
Get a free, no-obligation estimate from Southern California’s most trusted HGDB contractor. Call (323) 317-4828 or request online.