Before the house, i.e. before the holy house, or before the temple as this is explained, 1 Chronicles 3:17, lest it should be understood of the most holy house, of which he had spoken before. Thirty and five cubits high, to wit, both of them; of which See Poole on "1 Kings 7:15".
Related Commentaries of 2 Chronicles 3:15
2 Chronicles 3:15
15 Also he made before the house two pillars of thirty and five cubits high,g and the chapiter that was on the top of each of them was five cubits.