My numbers are from 25 years ago, so cost per SF for similar is probably $30+ a foot now, and engineer costs are much higher, but the percentages stay the same.

My numbers are from 25 years ago, so cost per SF for similar is probably $30+ a foot now, and engineer costs are much higher, but the percentages stay the same. A 3.5 meter by 3.5 meter room is what many call a "two man" office. We had essentially 2.8m by 2.8m single persons, again you only need a minor more space than a cubicle. Doorway (which a cubicle needs too but not a swinging doorway) and mildly thicker walls. The ventilation goes through the ceiling, power in the walls. You can't always have an exterior window in every office, but you can have interior glass. It's important to have enough natural light in the hallway so that the interior glass carries the natural light into the offices. You don't want long dark hallways that can only be lit by artificial light. Break up the hallway with an exterior window or an office with windows and interior glass.