This work explores the double effect of urban compactness on building energy performance in a Mediterranean climate, namely the increase of urban heat island (UHI) intensity and the decrease of solar radiation availability on building façades. The energy demand of a test apartment has been calculated under varying conditions of UHI intensity and solar radiation for different urban textures. Results show robust relationships between the energy demand and the ‘site coverage ratio’ of the buildings. This demonstrates that compact urban textures are more energy efficient than less dense urban patterns in a Mediterranean climate.