In continuous operation since 1984, Cass Sowatsky Consulting Architects runs a thirteen-person federal design-build practice from 3569 Fifth Avenue in Hillcrest under two AIA-credentialed principal architects. The studio concentrates on architecture, planning, BIM, and sustainable design for federal agencies and large institutional clients, with Southwest Builders brought in as the construction partner on design-build deliveries where federal contracting requirements demand a GC already familiar with FAR compliance and institutional scopes rather than ad-hoc commercial subs. A cardinal firm rule requires a principal architect to personally manage and seal every project during all critical design phases, a staffing discipline that scales from small renovations to federal portfolios valued in the billions. The planning-forward federal focus sets CSCA apart from smaller commercial-tier neighbors along Fifth Avenue such as ZAAP Architecture and Planning, which work primarily in the private commercial sector. Sustainable design credentials, in-house BIM coordination, and a published design portfolio combine into a federal-ready qualification package. Full federal design-build deliveries — where the architect of record carries responsibility for subcontractor coordination, documentation, and construction administration through closeout — define the top of the firm's capability stack.