Well there is a lot of information that can be covered here actually.
First the basics:
Exposure, this is the way we can control how bright our image is, besides the actual intensity of the light element it self we can control how bright the image it is with the Exposures controls.
On Max this is divided in two main part, one is under environment panel, the other controls are in the camera it self. For easy controls you only need to concentrate on the EV control, the larger the number, the darker the image will be. If you want to go in more details the other controls make this 3d Max camera work like a real life photo/video camera.
Light intensity,
When you are using VRay Sun/Sky, you'll realize that the default values are adjusted to match a 'real life' situation so it is very bright. If you put a regular light in your scene the intensity of this light will be way lower compared to your Sun/Sky.
This also happens in real life, if you are outside of a building and look to the inside, you'll see everything is dark inside. Unless of course you put a lot of lights inside of the building.
In your Case you need to adjust the interior light intensity until you can see the interiors. If you are using Irradiance and Light Cache this will be more easy than if you are using brute force, this last one need more bounces to get interiors bright.
Environment Lighting.
By default VRay's Sun/Sky will create very nice results. Some people uses HDRI to illuminate their scenes,using a Dome light and applying that HDRI on the texture slot of that light, this also help with the reflections.
If you are using VRay's Sun/Sky you can still use a dome or Sphere object and apply a self illuminated Material to it, then on the texture slot you can put a panoramic image and this will be the sky you'll see in your scene. You need to flip the normals in your sphere if they are not facing correctly, also you need to do right click on it and choose on the properties of that object to do not cast shadows, Otherwise your sun will be cover by this dome and your scene will be darker.
Other way would be going to the properties of your VRay sun and exclude that dome/sphere.
You could use a single plane behind your house if you like too, to fake a background or sky, but you need to do the same procedure explained above, apply a self illuminated material with a sky image and exclude that plane from illuminations and shadows.
I would strongly recommend to use the present that comes with VRay, on the latest releases all those present are adjusted to get a good ration of rendering/quality.
Hope this help, if you have more questions let me know 😉
