Originally founded in Hillcrest in 2007 as CitiZen Design Studio and later rebranded, Jimmy Sullivan Studio is a sustainable residential and light-commercial design practice with a second office in New York's West Village. The studio is certified through the NGLCC National LGBT Chamber of Commerce and the San Diego Equality Business Association, serving a client base that overlaps heavily with the sustainable landscape portfolio of GroundLevel Landscape Architecture. Residential scope covers accessory dwelling units, custom homes from raw land, historic bungalow remodels, energy-efficient renovations, and sustainable green builds calibrated to California Title 24 requirements. Every design package integrates full 3D models, photorealistic renderings, and VR walkthroughs, a visualization workflow built to hand off directly to ADU-focused builders including Honeycomb Design & Remodel. Commercial engagements lean into restaurant tenant improvements and retail boutique buildouts, drawing on the principal's prior Bay Area firm experience before the San Diego relocation. The most complex work is top-to-bottom midcentury modern home redesigns that have to balance strict California permitting constraints with ground-up reconfiguration of floor plan, envelope, and site work.