Faire vs. Etre meaning in context

Question

Is there any difference in meaning between the use of faire and etre contextually? Or, are they freely interchangeable?

I guess my main concern is, is there an example of a time when faire would be chosen over etre and vice versa?

Cécile Janty-Davies · Accepted Answer

Just to add to what Jim has said -
No, "faire"  and "être" are not interchangeable when expressing dimensions in French.
They are used in different contexts:
1. "Faire" is used for height, width, and length measurements.
For example: -

La table fait 2 mètres de long = The table is 2 meters long
L'arbre fait 10 mètres de haut = The tree is 10 meters tall
 Ce terrain est large de 50 mètres= This piece of land is 50m wide

2. "Être" is used with adjectives describing size or when stating a precise measurement.
For example:

La piscine est profonde de 3 mètres = The swimming pool is 3 m deep 
Ce sapin est haut de 2 mètres = This Christmas tree is 2 m tall
L'eau est chaude de 40 degrés = The water is 40 C hot

In general: 
Use "faire" + de + measurement + unit for dimensions. 
Use "être" + adjective for general size descriptions
Use "être" + specific measurement when stating a precise figure without mentioning the dimension (height, width, etc.)
Bonne continuation et Joyeux Noël !

Jim Jones · Answer

Bonjour Matthew,As the lesson explains:-"Note: to indicate measurements, you use faire [dimension] sur (by) [dimension]."But to comment on the item in terms of a description you would use être.So imagine that you are a salesperson showing someone around a property for sale. You would use "that item (bed or wardrobe or whatever) is (être) of a particular dimension.But if you were required to prove that and, therefore, needed to measure the piece in front of the client;  you would carry out the measurement and declare the result by using faire (this piece makes X metres of length or width).So no, they are not interchangeable without clear context as described above.Hope this helpsBonne journéeJim