Addition Design
Develop a tailored addition or alteration for a single-family home or residential building, balancing existing character, new function, sustainability, and timeless design.
Planning a home addition requires more than attractive ideas—it calls for an architect who can understand your goals, coordinate consultants, navigate permits, and guide the project toward completion. This resource explains what to look for, which questions to ask, and how an integrated residential design practice can help homeowners in Los Angeles and Colorado’s Roaring Fork Valley make informed decisions.

Explore integrated design, permitting, visualization, and project guidance for thoughtful residential additions and alterations.
Develop a tailored addition or alteration for a single-family home or residential building, balancing existing character, new function, sustainability, and timeless design.
Receive guidance through building permit procurement, with coordination among clients, consultants, contractors, and relevant municipal agencies throughout the process.
Coordinate interior design, custom cabinetry, furniture, and built-ins so the addition feels connected to the home rather than treated as an isolated extension.
Use immersive VR presentations and three-dimensional models to study proposed spaces, understand design decisions, and participate more confidently in the process.
Continue with project guidance and construction administration from design and permitting through implementation and completion, supporting clear coordination across the team.
Approach additions and remodels in Historical Preservation Overlay Zones with sensitivity to existing architectural integrity and opportunities for modern sustainable systems.
The right architect helps turn an addition from an early concept into a coordinated residential project. Ortiz Mexia Projects, Inc. combines architectural design, interiors, permitting support, visualization, and construction guidance for homes in Los Angeles and the Roaring Fork Valley. This integrated approach is especially useful when an addition must respect an existing home, local municipal requirements, and the character of its surroundings.

Work with a design-led practice that connects architectural thinking with practical project coordination.
Coordinate architecture, interiors, furniture, cabinetry, and built-ins through one connected design practice.
Create elegant residential additions suited to lasting use rather than short-lived trends.
Navigate project permitting with support for clients, consultants, contractors, and municipal agencies.
Serve Los Angeles and the Roaring Fork Valley with awareness of distinct residential contexts.
Get to know the principal behind this architecture and design practice.

Assoc. AIA, Principal
Santiago Ortiz is the founder and principal of Ortiz Mexia Projects, Inc., an architecture and design practice serving Los Angeles and Colorado's Roaring Fork Valley. Born and raised in Colombia, Santiago moved to Providence, Rhode Island, to pursue his passion for design, graduating from the Rhode Island School of Design in 1999 with degrees in Architecture and Fine Arts. After relocating to Los Angeles, he honed his craft at small architecture firms specializing in high-end custom residences and boutique commercial spaces before founding his own practice in 2006. Santiago is an Associate Member of The American Institute of Architects and brings a timeless, elegant sensibility to every project, from custom furniture and built-ins to full-scale residential construction. His work has been featured in Interior Design Magazine and the Los Angeles Times, reflecting his commitment to thoughtful, well-crafted design.
A small addition may still benefit from an architect when the project changes the home’s layout, affects structural or exterior conditions, requires permits, or must respond to a historic overlay zone. An architect can help clarify feasibility, develop coordinated drawings, support permitting, and connect design decisions with construction. The appropriate level of service depends on the project’s scope and municipal requirements.
Talk with the design team about your home, goals, and project direction.
By appointment, the studio supports residential projects across Los Angeles and Colorado’s Roaring Fork Valley.
Los Angeles, CA
Primary Region
Roaring Fork Valley
Colorado Region
By Appointment
Availability
Confirm availability and discuss your addition with the studio.
Professional association membership held by principal Santiago Ortiz.
Projects featured in Interior Design Magazine and the Los Angeles Times.
Ortiz-Wheeler Residence featured in the Venice Vista Spring Home Tour.
Share your property, goals, and questions so the studio can discuss the right next step.
For immediate assistance, feel free to give us a direct call at +1 (310) 600-0241.
For immediate assistance, feel free to give us a direct call at +1 (310) 600-0241.