Ok, this almost looks do-able as a toc. Is there any way of having 3 headings on 1 row like:

Heading 1 - Heading 2 - heading 3

Rather than

Heading 1
Heading 2
Heading 3

As this will read as:
Reference number - Affected Area - Corrective Action

Eg:

12/14 - Kitchen - Hole leading through external wall needs to be filled

The document is A4 landscape and this would prevent a lot of dead space.

Thanks in advance