Safety is a primary concern to buyers so when a home inspector brings to the attention a problem that deals with safety it will likely become a sticking point in negotiations.
A frequent concern is that of small bedroom windows, particularly in the basement, not meeting the building code for egress. Window size in the basement is often restricted due to the foundation elevation however windows in other rooms which are being utilized as bedrooms may also not meet the required code. Specific minimum standards have been established for bedrooms so that a person can safely exit or a firefighter can enter in case of an emergency. This is referred to as meeting egress. Requirements for a room to qualify as a bedroom are set out in the National Building Code and apply not just to basement bedrooms but apply, as well, to any room being utilized as a bedroom.
Unless there is a door that provides direct access to the exterior, you need a window that meets egress (exit) requirements of the code. It is not just size that determines whether a window meets the code for an egress window, the style and location of the window will be important as well
In addition to the size specifications for the window, it must be operable from the inside “without the use of tools or special knowledge” The window must also be accessible. If the window is too high to reach from the floor in order to open, then a bench, chair or step must be fixed below the window. If the window opens into a window-well, the well should not block the opening of the window and a minimum clearance is needed in front of the window. Even if you do have an exit door to the outside of your home from a bedroom there is still a requirement for a window. For all bedrooms, there is a requirement for a 5% glass area of the area served
As the building code does change, you should check with your local planning department and verify with them the current code for windows.