The grades of three Building Products stocks are better this week, according to the Portfolio Grader database. Every one of these stocks has an “A” (“strong buy”) or “B” overall (“buy”) rating.

PGT Inc. (NASDAQ:PGTI) is progressing from last week’s rating of B (“buy”) as the company improves to an A (“strong buy”) this week. PGT manufactures and supplies residential impact-resistant windows and doors. In Portfolio Grader’s specific subcategories of Earnings Revisions and Earnings Surprise, PGTI also gets A’s. The stock price has risen 32.1% over the past month, better than the 1.8% increase the Nasdaq has seen over the same period of time. For more information, get Portfolio Grader’s complete analysis of PGTI stock.

AAON’s (NASDAQ:AAON) grade is moving up to a B (“buy”) this week from last week’s C (“hold”). AAON manufactures and sells air-conditioning and heating equipment. Investors seem to agree with the upgraded status of the stock, and have pushed the stock up 5.5% over the past month. For more information, get Portfolio Grader’s complete analysis of AAON stock.

NCI Building Systems (NYSE:NCS) gets a higher grade this week, advancing from a C last week to a B. NCI Building Systems designs, manufactures, and markets metal engineered building systems and products for the building industry. Wall Street has pushed the stock higher by 5.4% over the past month. For more information, get Portfolio Grader’s complete analysis of NCS stock.

Louis Navellier’s proprietary Portfolio Grader stock ranking system assesses roughly 5,000 companies every week based on a number of fundamental and quantitative measures. Stocks are given a letter grade based on their results — with A being “strong buy,” and F being “strong sell.” Explore the tool here.