My husband and I are buying our first home. During the inspection, our inspector said there could be lead-based paint (due to the age of the house) under the several layers of existing paint, and although nothing is chipped or flaking, NOT to sand the walls (the sellers don't know if lead paint exists under the current paint, and I'd rather not sand the walls and take chances). To save money, we want to repaint the interior ourselves and I'm not quite sure how to do it properly without sanding the walls first. The walls are in good condition, with no holes or cracks, and are a cream color, and we intend to paint over it with another light color, but don't want it to look like we cut corners. What's the best way to paint over the existing paint and still have good results without sanding?
If the walls are in good condition then why would you even have to anticipate sanding?
Prepare the surfaces by cleaning them well using a bucket of hot water and TSP (trisodium phosphate) cleaner. Make sure to wear protective rubber gloves. This will get years of dirt and gunk off the walls to make it a good place for new paint to adhere. The TSP will even help to dull glossy surfaces.
I have also found that the cleaner "409" will also help to dull especially glossy paint surfaces but they do also produce products especially for the purpose.
lead-based paint under the several layers of existing paint
Planning on attacking the walls with a belt sander? The lead paint will only be an issue if you actually sand the lead-based layer. Since most paint jobs don't require a complete strip you'll be fine. The point of sanding is to remove surface dirt and glossy finishes - a few passes with a hand sander is all you really need to do.
There will probably be places in the wallboard that need attention - in this case use a knife to open the crack up and patch it. sanding the patch material flush is the same idea - you will not be touching any old paint.