Mechanical and electrical system design of modifications to the existing Richmond Airport Automotive Maintenance Facility to provide an environment suitable for maintaining compressed natural gas vehicles. This was a phased project to allow for a temporary maintenance location while the comprehensive upgrades were being designed and constructed. The existing high temperature catalytic heaters and all fans and equipment that posed a sparking risk were removed. The mechanical systems included a 2 speed building exhaust system controlled by the facility carbon monoxide and nitrogen dioxide detection system and a gas fired makeup air unit. Fuel gas design included a piping system that supported the initial use of propane before transitioning the site to natural gas.