It takes years to learn and master how to do each of the tasks it takes to build a house or renovate a kitchen.
不懂第二个it takes的意思是,在句中作什么结构成分,只感觉it像是形式主语,但takes为何如此用?
it takes to build a house or renovate a kitchen为定语从句修饰tasks。意为盖房屋或改造厨房所需要的各种技艺。tasks=任务,在此翻译为技艺。关系代词that指代tasks。在从句中作宾语,被省略了。