Vacuum glazing, a new form of transparent thermal insulation, consists of two closely spaced sheets of glass which are sealed around their edges, forming an internal space which is then evacuated to a very low pressure (< 0.1 Pa). The separation of the glass panes is maintained against atmospheric pressure by an array of support pillars. In this thesis, two effects relating to these support pillars are studied. The thermal resistances associated with the heat flow through a single pillar, and through the pillar array, are calculated using a simple analytic method, and using a two—dimensional axisymmetric finite element model. The results of both approaches are in very good agreement, and are validated by comparison with experimental data. It is shown that, for many purposes, the amount of heat which flows through the pillars can be determined by assuming that this heat flow is evenly distributed over the area of the glass. The heat flow through support pillars gives rise to periodic temperature variations on the external surfaces of the glazing. The dependence of these variations on various glazing parameters is studied using a finite element model, and by using two superposition methods. The results obtained using these approaches are in very good agreement both with each other and with experimental infrared thermographic measurements of surface temperatures. The support pillars in vacuum glazing slowly indent into the glass sheets due to very large stresses caused by atmospheric pressure. This creeping indentation is studied at temperatures of 230 - 350 °C. Long-term data are obtained by examining old vacuum glazing samples which had been evacuated at room temperature for periods of up to 4 years. The experimental results indicate that indentation creep can be explained as a superposition of linear viscoelastic deformation and linear viscous flow. A method is presented by which the coefficient of shear viscosity can be calculated from indentation data. The measured viscosity of standard soda lime silicate window glass at room temperature is (1.4 +0.2,—0.4 X 102') Pa s. A method is described for calculating the indentation rates of support pillars in any vacuum glazing as a function of temperature, pillar radius, and pillar separation. It is shown that the rate of indentation creep is acceptably small at temperatures below 200 °C for any practical design of vacuum glazing.