Looking good so far.
As to file size, are you using components? Also, are you using any complicated models where something simple would do? For instance, what looks to be a winged sculpture below the three red art panels in the living room could be achieved with three simple pieces of geometry painted a simple color, as opposed to a detailed component, since the detailing is lost from this distance. Also, if you've modeled the entire house, use differrent layers and turn them off when contents not seen in a particular view.
The texture on the seesaw isn't realistic - the wood grain looks too large, and the grain on the long board should be running parallel with that board, not vertical. Unless the house is built on the very edge of a cliff, the lack of a background looks odd. It's obvious that the two poolside chairs in the foreground are the same component (shape of the cushion) - flip one, so it's not so obvious. There are more experienced people than me who can give more pointers, but they would probably want ot know which rendering program you are using.