Investors looking for stocks in the Building Products - Home Builders sector might want to consider either KB Home (KBH) or NVR (NVR). But which of these two companies is the best option for those looking for undervalued stocks? Let's take a closer look.The best way to find great value stocks is to pair a strong Zacks Rank with an impressive grade in the Value category of our Style Scores system. The proven Zacks Rank emphasizes companies with positive estimate revision trends, and our Style Scores highlight stocks with specific traits.KB Home and NVR are sporting Zacks Ranks of #2 (Buy) and #3 (Hold), respectively, right now. This system places an emphasis on companies that have seen positive earnings estimate revisions, so investors should feel comfortable knowing that KBH is likely seeing its earnings outlook improve to a greater extent. But this is only part of the picture for value investors.Value investors also tend to look at a number of traditional, tried-and-true figures to help them find stocks that they believe are undervalued at their current share price levels.The Value category of the Style Scores system identifies undervalued companies by looking at a number of key metrics. These include the long-favored P/E ratio, P/S ratio, earnings yield, cash flow per share, and a variety of other fundamentals that help us determine a company's fair value.KBH currently has a forward P/E ratio of 8.10, while NVR has a forward P/E of 17.99. We also note that KBH has a PEG ratio of 0.46. This figure is similar to the commonly-used P/E ratio, with the PEG ratio also factoring in a company's expected earnings growth rate. NVR currently has a PEG ratio of 1.39.Another notable valuation metric for KBH is its P/B ratio of 1.22. The P/B is a method of comparing a stock's market value to its book value, which is defined as total assets minus total liabilities. By comparison, NVR has a P/B of 5.23.Based on these metrics and many more, KBH holds a Value grade of A, while NVR has a Value grade of C.KBH stands above NVR thanks to its solid earnings outlook, and based on these valuation figures, we also feel that KBH is the superior value option right now.Want the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report KB Home (KBH): Free Stock Analysis Report NVR, Inc. (NVR): Free Stock Analysis Report To read this article on Zacks.com click here. Zacks Investment Research