Stop "empty" attributes from appearing in additional information in Magento site

We'd like the attibutes that have no value for a product on our magento website not to be listed for each product. We have had some work done before now that added an "N/A" to each empty field. We'd like this changed so that if there is nothing to show, the attribute isn't listed.
For example, if the product doesn't have a value for 'Doors', it currently shows:
'Doors N/A'
We would prefer that it didn't show at all. I've attached a photo of how it currently looks. Our site can be found at jecltd.com.
We would also like the red bar/line at the bottom to be moved to the bottom of the table, rather than one line above.
Please don't hesitate to ask for further clarification if required.