Seaboard is a mixed-use historic landmark designated building which includes ground level retail, 5 floors of commercial office tenant space, and 5 levels of privately owned condos. Delta E is supporting the owner in studying mechanical system renovation and replacement options, including how options support building decarbonization efforts and long-term compliance for Washington State Clean Buildings Standard, and Seattle's Building Emissions Performance Standard. The study concluded with recommendation of the replacement of the entire mechanical system - removing them from natural gas while dealing with one of the most constrained roof-top mechanical spaces in the City of Seattle and multi-million-dollar condominiums on all sides of the project.