The meaning of “相”
My sentence is：修建房屋时也要考虑和周围环境相协调。
What is the function of “相” in this sentence?

Question

Answer

Good question!
Here is a fixed phrase: "和(Or与)....相协调" means In harmony with something.
Same use with "和(Or与)....相一致"。
Example: 我们必须确保人口的增长和环境相协调。

Answer

相 here is a short version of 相互 which means mutually or to each other. Eg: 相融 means 相互融合。相适应meas 相互适应。It means it works both ways.