Concentrating solar energy systems can serve many applications beyond electric power generation. GlassPoint Solar has introduced an Enclosed Trough solar once-through steam generator (OTSG) system designed for challenging environments and to meet all requirements for solar thermal enhanced oil recovery (EOR). Parabolic trough collectors are enclosed within a modified agricultural glasshouse, which protects the collectors from wind, sand and dust common in oilfield environments, and eliminates energy losses due to wind. Automatic glasshouse washing and air filtration equipment dramatically reduce soiling and related losses. The once-through boiler process allows the use of feedwater with total dissolved solids as high as 30, 000 ppm while producing 80% quality steam at 100 bar, matching typical EOR specifications. The construction of a 17, 280m2 pilot plant in southern Oman is reviewed. Construction was completed in 11 months, on time and on budget, with zero lost time injuries. This paper reports on the plant design and construction methodologies and measurements of construction labor productivity compared to long term build speed and cost objectives.