A luminaire assembly includes: a substrate extending along a first direction comprising a first material having a first coefficient of thermal expansion; a plurality of light emitting elements (LEEs) secured to the substrate and arranged along the first direction; a light guide composed of a material having a second coefficient of thermal expansion different over an operating temperature range; a plurality of optical elements arranged along the first direction, each optical element being positioned to receive light emitted from a corresponding one or more of the LEEs and to direct the light to an edge of the light guide; a housing; and a heat coupling layer arranged between the substrate and the housing. The substrate and the heat coupling layer are constructed so that each of the plurality of LEEs, while secured to the substrate, remain registered with their corresponding optical element over the operating temperature range.