I grow seeds just fine with my basement light set up. It is a few degrees cooler than up stairs. I use a heating mat for all but seeds that germinate at cool temperatures , and I have a mylar sheet draped over my stand to not only reflect light but keep it a bit warmer inside.

Be sure to remove the heat mats once they are rooted or you may burn the roots. If you want them for extra heat invert an extra tray--one with lots of holes and put the tray with plants on top.or support the plant tray --or-- inverted plant saucers. You'll still get the heat and not burn the roots. You can keep the mylar sheets on until planting time