The thermal performance of a sunspace attached to a living room located in Amman-Jordan has been investigated. Six configurations that differ by the ratio of glazed surface area to opaque surfaces area are studied. A novel configuration that utilizes an inclined front surface is thermally investigated. The effect of orientation of the sunspace, opaque wall and floor absorption coefficients and number of glass layers on the thermal performance is evaluated. Results show that the sunspace reduces the heating load during the winter, while it creates a serious overheating problem during summer. The contribution of reducing heating requirements increases with increasing the ratio of glazed surface to opaque surface area. Also, the optimal contribution was obtained when the sunspace was oriented to the south. Two passive cooling techniques are proposed and evaluated to overcome the summer overheating problem. Additionally, a passive heating technique is proposed to minimize the thermal losses during winter nights. Internal shading and night ventilation successfully minimize the overheating problem. Employing the three passive techniques with sunspace, results show that as high as 42% reductions in annual heating and cooling load can be achieved. Utilizing an inclined front surface with double layer of glass can further reduce heating and cooling load requirements. (C) 2011 Elsevier B.V. All rights reserved.