Glass casting displays great forming potential allowing for the realisation of three-dimensional glass elements of virtually any shape and size. Disposable mould technology seems to be ideal for the fabrication of such customised and complex geometries, including for architectural and structural cast glass components deriving from structural Topology Optimization (TO), since it offers great shape freedom and cost effectiveness. However, currently, glass casting on disposable moulds faces the major drawback of a resulting rough and opaque glass surface quality, requiring considerable post-processing to yield a glossy, smooth surface. Aim of this research is to improve the surface quality of complex glass components cast in disposable moulds, directly during demoulding, reducing in this way the need for post-processing. In specific, the research focuses on series of kiln-cast laboratory experiments at various maximum firing temperatures / annealing schedules involving the use of two different types of disposable moulds, 3D-printed sand moulds (3DPSM) and silica plaster moulds (Crystalcast®), and the application of refractory coatings, coating combinations and protective layers.