I estimate the interior living space is about 900 square feet. If it were a house it would probably feel cramped. I don’t have headroom over the kitchen sink (dang!) and a few other places, and I frequently have to ask small people to move out of my way in narrow passages. But it isn’t a house, and by boat standards it has an immense amount of space. As Tanya has written elsewhere, we have far less "stuff" aboard which is necessary for weight consideration and also helps alot for preserving the spaciousness.
Strangely, we feel more cramped in our house than we do on the boat. On the boat we can usually see for miles in at least three directions. Even when we’re tied up at the dock we have an unobstructed view of the sun setting over the water, and we’re constantly aware of the sky, the breeze, and the tide. At the house when we look out the window we can’t even see a 100 yards before our vision is blocked by houses, trees, or fences, and can only see the sky by walking outside and looking up.