About Us

Dan Ionescu, NCARB, AIA is the founder and principal of Dan Ionescu Architects & Planners (DIAP), an international planning and architectural design firm based in San Mateo, California. Since 1982, Mr. Ionescu has been leading his innovative international staff to complete sophisticated planning and design projects, ranging from the redevelopment of old rural areas in Europe and regional urban planning in China, to residential architecture and large mixed-use projects in urban areas in the United States and Europe.

Mr. Ionescu brings his site-specific approach and extensive international experience to each project. He excels at designing for complex programs. Mr. Ionescu considers the environmental, historic, demographic, political, and economic aspects of an area and brings them together to form a comprehensive strategic plan. DIAP draws from Mr. Ionescu's forward-looking planning principles and global experience with outstanding results, developing successful strategic plans and urban designs to match the character and objectives of each project.


Phone: +1 (650) 570-6681

Who We Are

What We Do

How We Do It

Dan Ionescu Architects & Planners (DIAP) is an experienced and versatile design firm based in the San Francisco Bay Area, which was founded in 1982 by Dan Ionescu himself. We employ a dynamic team of architects and planners, with strong educational backgrounds and diverse experiences. Our process entails maintaining longstanding relationships with talented consultants in order to provide complete support for client and project needs. DIAP has the proven ability to work around the world and has never had a project denied. A policy of close communication with clients ensures an effective and flexible design process.

DIAP's has an extensive portfolio that includes work on four continents. Our assignments have ranged from strategic regional plans to mixed-use developments and encompass every type of structure—and infrastructure. The creative team at DIAP produces sophisticated designs, with innovative solutions tailored to take full advantage of the opportunities and challenges of each project. We provide elegant solutions for complex design projects and produce functional, beautiful, cost-effective, and sustainable designs. DIAP brings its site-specific approach and extensive international experience to each project and is committed to close communication with clients.


This strategic design matrix is the key to how we as a company do business. It’s a versatile approach that allows us to strategically adapt and deliver one-of-a-kind designs to our clients. DIAP is open to working with other firms in multiple capacities. As a versatile company, we’re able to work with you throughout the whole entire project, on a single phase, or as a consultant.

Strategic design principals are incorporated into each and every project with which DIAP is associated. These key principals include different project elements related to each category of the matrix.