One of the first zero energy houses is Socrates Solar House. During 470 B.C., Socrates was trying to find an answer to the following question: "What is an optimum house shape that stays warm in winter and cool in summer?"
His solution was a trapezoid shaped house with the longest side facing the south.
In order to avoid winter winds, the side that was facing north was the shortest side of the trapezoid shaped house, had thicker wall and small sized windows. The side of the house that was facing south, was the longest side of the trapezoid shaped house with big sized windows and doors and overhanged roof, so it would allow winter sun to penetrate into the house and still block hot summer sun, which its orbit is higher in summer than in winter. It was also recommended to plant deciduous trees on southern side of the house, so they would block summer sun and allow winter sun penetrate the house and evergreen trees on northern side of the house to avoid winter winds.
Modern architectures base their designs on Socrates Solar House in order to optimise pasive houses in general and zero energy houses in particular, using insulating materials and many other techniques.