וַיְהִ֗י מִקְצֵה֙ עֶשְׂרִ֣ים שָׁנָ֔ה אֲשֶׁר־בָּנָ֥ה שְׁלֹמֹ֖ה אֶת־שְׁנֵ֣י הַבָּתִּ֑ים אֶת־בֵּ֥ית יְהוָ֖ה וְאֶת־בֵּ֥ית הַמֶּֽלֶךְ׃
And it came to pass at the end of twenty years, wherein Solomon had built the two houses, the house of the LORD and the king’s house—
Rashi on I Kings
Twenty years. I.e., seven years [to build] the Beis Hamikdosh, and thirteen years [to build] his own palace, as mentioned above.10Above 6:38, and 7:1.