I've just created a new template to be used on our wiki:
Template: Breadcrumb

Then I replaced all references to {{Template: Category=Housing and construction}}, whose content was

'''[[Main Page|Main]]''' > '''[[:Category:Housing and construction|Housing and construction]]'''
[[Category:Housing and construction]]

with references to the new breadcrumb template, whose content is basically this:

'''[[Main Page|Main]]''' > '''[[:Category:{{{1}}}|{{{1}}}]]'''
[[Category:{{{1}}}]]

We must update the breadcrumb template so that it can accept any number of parameters and create the breadcrumb parts accordingly.

We should also replace the other templates of the form {{Category=SOMETHING}} (only those which are one-level deep for now) with {{Breadcrumb|SOMETHING}}.

Can you help me with that?