You do NOT want to use Word (a word processor) to define a room showing doors, windows or any type of scale. If anything, PowerPoint would be a better option...and even then I am not so sure you are going to get what you want. I spent the better part of the last 15 years constructing those type of pictorials but did so in suitable software (MS Visio, AutoCAD, et al).

Do you have access to Visio? That would be your best option.