Every detail which we will have to deal with taken into cons

这个是take 的宾语提前 和 省略的if 结构还有个关系从句共同导致的结果
首先还原take
taken every detail we will have to deal with into consideration,our design seems to be feasible.
if 从句被分词替代,因为主语是our design对于take是被动语态
再次还原是：
if our design is taken every detail which we will have to deal with into consideration,our design seems to be feasible.

take into consideration 固定搭配

这句话你没打完， 这里只是一个从句的部分，表示所有我们讨论的细节都会被列入考虑之中，下一句才是主句。