Lauren Thomsen Design is an award winning Philadelphia based architectural design firm. We specialize in complex and historic renovations, deep energy retrofits, and high performance new construction.

Our work is based on the fundamental belief in the value of space, and the ability of good design to enrich people's lives. We take on projects of a broad range of program and scale in the office, and work closely with our clients to understand context and to define the unique story of each project.

We love not only the outcome, but the process of design, and it is our goal to make sure that our clients do too. Working holistically, we lead interdisciplinary project teams to deliver interesting, sustainable, and well coordinated design solutions through the use of innovative digital tools and our expertise in material and building systems. 

Most importantly, we recognize that our projects are not simply a built output that is designed, constructed, and then turned over to a client. We see our projects as ecosystems that must serve owners and occupants for their entire life-cycle, and embrace the responsibility to deliver the best possible design solutions accordingly.

LTD is a certified woman owned business with the WBENC and a Local Business Entity with the City of Philadelphia, and we are licensed to practice in Pennsylvania, New Jersey, and New York.

Learn more about our Team here.

Awards + Press

Akman, Terri. “Bringing the Outdoors In.” The Philadelphia Inquirer, March 28, 2023.

Passive House Podcast EP. 115: Lauren Thomsen, Lauren Thomsen Design
Passive House co-host Zach Smenke interviews Lauren on the origin of her interest in architecture and her journey to Passive House design.

Green Building United Northern Liberties Passive House Tour, September 2022.

AIA Philadelphia: On the Rise Exhibition and Opening Reception, June 2022.
An Annual exhibition highlighting the winners of the AIA Philadelphia’s Young Architect Award and the Philadelphia Emerging Architect Prize.

Passive House Accelerator Live! “Northern Liberties Passive Rowhouse.” June 2022.
Matt and Lauren discuss challenges and opportunities that have arisen during the design and construction of a new construction single-family Passive House rowhouse. They are joined by Ralph Loielo and John Roderick of Scribe Design Build, and guest host Kit Elsworth of Kieran Timberlake.

“The Resilience of the Row: Thoughts and Discussion on Working in a City of Homes”
With a specific focus on the evolution and adaptation of the row house typology, Lauren presents to AIA Philadelphia’s PEA Committee on the challenges and opportunities associated with working in the rich historical context of Philadelphia.

AIA Philadelphia PEA (Philadelphia Emerging Architect) Prize Recipient, 2021.
The PEA Prize is an annual juried award by AIA Philadelphia that recognizes an emerging architecture firm producing high-quality design and thinking within the Philadelphia region.

“Keeping it Real” Golden Cone Award. PARK(ing) Day PHL 2021.

“14 Row Houses and Brownstones “Before & After” Their Much-Needed Makeovers”
For Dwell. By Melissa Dalton. August 2021.

“Architects Share Helpful Tips From Their Own Home Renovations”
For Dwell. By Melissa Dalton. August 2021.

“Before & After: A Philadelphia Architect Opens Up Her Historic Row House”
For Dwell. By Melissa Dalton. September 2020.

Design Services

Project Planning and Feasibility Studies
Zoning Analysis
Site Planning
Code Analysis
Space Planning
Architectural Design and Documentation
Interior Design
High Performance Design
Passive House Design and Certification
LEED Certification
Visualization
Contractor Bidding and Procurement
Construction Administration