Interiors can be photographed with either artificial, natural or mixed lighting.
Some interior photographs can consist of large rooms, exposition rooms, museums, theaters, shops and other interiors like your home or a workshop. In most cases, the interior photography will be better covered with a wide camera lens, so having at least a 28mm lens is a must when making such photographs because you will need to cover as much room as possible in your images. A 20mm lens is even better.
If there is too much natural light you can cover the windows a little, anyway, having too much light in the windows can damage your images by overexposing them in that particular area.
On the other hand, if the room is not so well illuminated, and you still don’t want to use the artificial light such as your flash, then you can compensate the lack of light by making a long exposure, and you may need a tripod for that to ensure crisp details.
You can take advantage of the sun rays near to sunrise or sunset, letting the light to fall in the room through a window, this kind of light can give beautiful results, if exposed properly.