According to the national association of Realtors, simply painting your door is the most cost effective return on investment when adding value to your home
A dated front door makes a house look cheap, and a warn front door makes a house look old and uncared for. Add a fresh coat of paint to bring things up to date. Most doors can be painted for prices beginning in the $100 range. So according to the research above, you're only spending $14.40 on your investment.