CanmetENERGY Ottawa is constructing a 600 kWth natural gas-fired pressurized chemical looping (PCL) pilot plant, with test work planned to commence in 2025. The reactor has been designed in collaboration with Hatch Ltd to house both the air and fuel reactors within a single vessel, greatly reducing plant footprint and equipment costs. It will operate in the bubbling mode and will test multiple oxygen carriers in the pressure range of 400-700 kPa(g). Many challenges arose during the course of designing and fabricating the pilot-scale reactor, including: finding vendors to fabricate specialized internal metal components; sourcing specialized materials of construction in small quantities; reducing the temperature of the exhaust gases in a low-cost, space-conscious way; designing for disassembly and replacement of prototype components; designing for equipment to operate under startup conditions; and incorporating access for inspections in areas of research interest. This work presents the approach to handling these challenges and the lessons learned throughout the design and fabrication of the PCL reactor.