Professional Room Additions & ADU Construction
Growing families and changing lifestyles often require more space. Rather than moving to a new home, room additions and Accessory Dwelling Units (ADUs) offer an excellent way to expand your property and increase its value. Guillen Construction Inc specializes in designing and building professional room additions, ADU structures, and garage conversions throughout Los Angeles. Our licensed general contracting team manages every aspect of your expansion project—from initial design and permitting through final construction and inspections.
Whether you need an additional bedroom, home office, guest house, or rental-income ADU, we bring expertise in modern design, structural engineering, permitting, and construction best practices. We understand Los Angeles zoning regulations, building codes, and the permit requirements for residential expansions. Our team handles complex coordination with city departments, structural engineers, and building inspectors, ensuring your project meets all requirements and progresses smoothly toward completion.
Why Choose Guillen Construction for Your Addition or ADU?
Adding square footage to your property is a significant undertaking that requires expertise in design, engineering, permits, and construction management. As a licensed general contractor with over 20 years of experience, Guillen Construction understands the complexities of residential additions and ADU projects. We manage every detail—from architectural planning and permit applications to foundation work, framing, utilities, finishes, and inspections. Our transparent communication, detailed project timelines, and quality-focused approach ensure your project succeeds on schedule and within budget.
We've successfully completed hundreds of additions and ADU projects in Los Angeles, transforming properties and creating valuable living spaces. Our clients appreciate our expertise in navigating local regulations, our professional team coordination, and our commitment to quality construction that adds genuine value to their homes.
What We Offer
Room Additions
Professional design and construction of bedroom additions, office spaces, family rooms, and other room expansions with seamless integration.
ADU Construction
Complete accessory dwelling unit construction including design, permitting, and build-out for rental income or guest housing.
Garage Conversions
Transform existing garage space into functional living areas including bedrooms, offices, or ADUs with proper insulation and utilities.
Permits & Approvals
Full permitting services including drawings preparation, city submissions, inspections coordination, and approval management.
Design & Planning
Professional architectural planning and design consultation to create spaces that maximize functionality and fit your home's character.
Foundation & Framing
Structural engineering, foundation work, framing, and all load-bearing construction executed to code and building standards.
Electrical & Plumbing
Licensed electrician and plumber coordination for all utility connections, circuits, fixtures, and code-compliant systems.
Inspections & Closeout
Full coordination with building inspectors and completion of all final inspections and punch-list items for proper project closeout.
Our Room Addition & ADU Process
We start with a detailed consultation to understand your vision, space needs, and budget. Our team then develops design concepts and can provide 3D renderings for visualization. We prepare all necessary architectural plans and submit permit applications to the city. Once permits are approved, we schedule construction and manage all contractors, inspections, and quality control throughout the build. Our project managers provide regular updates, manage the construction timeline, and handle any issues that arise. Upon completion of all inspections and punch-list items, you'll have a professionally constructed expansion that adds lasting value to your property.
ADU & Addition Projects in Los Angeles
Los Angeles has become a center for ADU development as homeowners recognize the benefits of additional living space and rental income potential. Guillen Construction stays current with evolving ADU regulations and zoning changes, helping our clients maximize their property potential within legal and practical frameworks. Whether you're looking to create a guest house, rental ADU, or additional living space, we bring the expertise, licensing, and project management skills necessary to complete your project successfully and compliantly.