This on-site role in Boston, MA; Charleston, SC; or Northfield, MN focuses on leading building sustainability initiatives through energy modeling, HVAC optimization, and decarbonization strategies. The ideal candidate has 5+ years in mechanical engineering or related fields, with expertise in sustainable design, building codes, and energy simulation software. Key responsibilities include guiding project teams, ensuring compliance with sustainability standards like LEED, analyzing local regulations, and supporting client relationships. The position offers opportunities for innovation, collaboration, and industry impact, with benefits including competitive salary, health plans, paid time off, and a 401K. Travel and fieldwork are required. Strong leadership, communication, and organizational skills are essential for success in this dynamic environment.