Door and window symbols: usually represented by simple lines and shapes. The door symbol may be a "|" shape, the window symbol may be a rectangle, sometimes with crossed slashes to represent glass.

Wall symbols: usually represented by straight or thick lines, representing the exterior and interior walls of a building. The symbol for a wall might be a straight line, and the corners of the wall would be represented by a small angle symbol.

Stairway symbol: usually represented by a set of parallel lines or arrows, marking the location and direction of a staircase. Arrows may indicate stairs going up or down.

Electrical symbols: Use specific icons to represent different types of electrical equipment, such as sockets, switches, lamps, etc. These icons may have unique shapes and markings to differentiate them.

Water pipes and pipe symbols: Line segments and arrows are used to represent the direction and connection points of pipes and water pipes. Arrows may indicate flow direction to differentiate between cold and hot water pipes, etc.

Furniture symbols: Commonly used furniture such as beds, sofas, tables, chairs, etc. may be represented by simplified icons. These symbols can help determine the layout and placement of furniture.

It should be noted that the specific symbols and their meanings may vary depending on the designer, region, or type of design drawing. If you encounter unclear symbols when viewing design drawings, it is best to consult the relevant designers or professionals for accurate explanation and understanding.