And they used laminated wood for the roof for a lot of structural materials things that weren't load-bearing.

他们在屋顶上使用了层压木材，很多结构材料都是不能承重的。

And our calculus showed that the risk of construction  overrun by having more onsite activities didn't justify the cost saving by using a cheaper  structural material.

我们的计算表明，通过进行更多现场活动而导致施工超支的风险并不能证明使用更便宜的结构材料可以节省成本。

So far, most of these alternatives are either too expensive to make or too early in development or are being adopted tentatively because concrete is such an important structural material.

到目前为止， 这些替代品中的大多数要么制造成本太高， 要么开发得太早，要么只是暂时采用， 因为混凝土是一种非常重要的结构材料。

In just three months to be precise … Concrete is a structural material that's cheaper  on a structural loading basis than steel might be, but it requires onsite speciality labour which  can slow down the construction process.

准确地说，只需三个月… … 混凝土是一种结构材料，在结构载荷基础上比钢材便宜，但它需要现场专业劳动力，这会减慢施工过程。