We are an architectural design and advisory group working from Sydney and Copenhagen. We help clients and collaborators unlock complex sites, existing buildings, public places, and early development ideas into clear architectural direction.

KOSY is led by Sebastian Grøgaard in Sydney and co-founded with Juan Ramirez in Copenhagen. The studio is shaped by senior international experience from Bjarke Ingels Group (BIG), 3XN Architects, Snøhetta, and other leading practices, alongside ongoing teaching and research at UNSW Sydney in adaptive reuse, density, climate, and high-performance architecture.

We keep the studio focused so senior design thinking stays close to the work. Depending on the project, KOSY can lead the architectural direction, support an existing team, or collaborate with trusted local architects and consultants to move ideas toward delivery. The aim is clear structure, strong ideas, and architecture that celebrates connections between people, place, culture, and environment.

Work

Architecture
Public places
Adaptive reuse
Workplace and commercial interiors
Development studies
Competitions
Feasibility and design strategy

Useful for

Early design direction
Adaptive reuse strategy
Public realm thinking
Development potential
Competition positioning
Concept-to-documentation support

Background

3XN 
Snøhetta
BIG
Laguarda.Low
UNSW

KOSY projects

Abarca Headquarters, 12-storey retrofit completed 2024
MBRIC, Research hub, construction documentation completed 2025, in progress

Recognition

MBRIC, CAAPR Puerto Rico Biennale Unbuilt Project of the Year
MBRIC, AIA Puerto Rico Honor Award for Unbuilt Design
MBRIC, Ceiba, international competition-winning research centre
Abarca Headquarters, San Juan, selected through international RFP
MBRIC, published in Designboom and Archdaily
Turku Museum, published in Archdaily

Selected founder experience

Major commercial, mixed-use, workplace, residential, adaptive reuse, facade, and public-realm projects completed at previous practices. Listed projects below are founder experience from previous roles, not KOSY commissions.

Google Headquarters Mountainview, commercial, US
The Spiral, commercial, US
2 Finsbury Avenue, commercial / adaptive reuse, UK
IQON Tower, residential, Ecuador
Vancouver House Podium, mixed use commercial/residential, Canada
King Toronto, residential, Canada 
Caulfield Grammar, education, Australia
Capitamall Xinduxin, retail, China