The noun "work" - countable or uncountable?

I am a native English speaker and have recently started working at an engineering firm in Eastern Europe as an environmental scientist. One of my roles within the company is to teach English to staff and I recently noticed that many of the company's employees use the noun "works", for example: "we will carry out engineering works".

I am qualified to teach English as a foreign language (CELTA) and I have always been taught that "work" is an uncountable noun, similar to water, i.e. we don't say "I have a lot of works." in the same way that we don't say "I have a lot of waters." The noun "work" is also listed as an uncountable noun in dictionaries.

In understood that the only exception was when referring to a factory or similar, e.g. a steel factory can be called a steelworks.

I told the staff about this mistake during my English lessons, but one of them came to me today and pointed out that in the FIDIC (an engineering institute) guidebook "Conditions of Contract for Construction", work is used as a countable noun with considerable frequency. I looked at the contents page and saw several examples: for example, "Commencement of Works", "Taking Over of Parts of the Works", etc. At the same time, I can also see that work has been used as an uncountable noun in the book, for example, "Resumption of Work", "Suspension of Work", etc.

As far as I'm concerned, this appears to be a mistake, but maybe I'm wrong? As a scientist, I'm not overly familiar with engineering terms - maybe that's the problem?

Can anyone help me with this at all? When can work be used as a countable noun?