What are the best changes to make to a house plan during the pre-start stage, considering layout, functionality, and energy efficiency?

During the pre-start stage, consider modifying the layout to improve functionality, such as relocating internal doors to enhance room flow or adjusting room dimensions for better furniture placement. Enhancing energy efficiency can be achieved by optimising window placement for natural light and ventilation, and considering the orientation of the house on the block. Small changes to the floor plan at this stage can significantly impact the liveability and comfort of your home.