On first glance, it looks like you're way over-illuminating your interior. Even on bright, sunny day with the light streaming in the sliding glass doors, there would not be that much light in an interior space if the visible exterior was even close to properly exposed. With the interior that exposed using normal lights, pretty much everything outside would be completely blown out. I suspect you probably intuitively know this from experience and can tell it looks funny, but can't put your finger on it.
To my eye, your interior lights are using several thousand watts of traditional incandescent power. These are the kinds of lights you use on a film set, not in a home interior. Interior fixtures usually use 1/10 that much go juice.
I suggest you first set up your baseline interior lighting with no Sun or any other exterior illumination at all. Next, turn off all your interior lights and set up your Sun. Then you can turn on both and adjust your camera exposure to capture a more realistic overall image exposure. Most of the time in real life, our eyes and our cameras just can't see such extreme differences in illumination at once.
Technical Director - C4D, Maya, AE, - Washington DC