Another way to add depth to the spaces at the front of the house would be to widen the house. The back of the house could be extended all the way along. This would mean that the corridors would need to move as well. It makes better sense to move the front walls either side of the central bay forward. The issue then is what to do about the roof line. The extended sections could be left flat, capped with some sort of dormer. Or the roof could be raised and replaced. I'm not sure if we'll get permission to raise the roofline.
One mistake homebuyers often make when looking at floor plans is over spending for the future, rather than planning for the present. You can always upgrade your home. From finishes and innovative additions to possibly adding area and amenities. Don't get oversold from a home selling agent or a developer's representative – only you know your budget. Plan for your budget now so you will feel comfortable living in your home and not feel “financially strained” each month to make payments on your home.