still trying to get an answer to this
There seems to be some confusion in the Probate Service, the Dublin Office say that "a valuation by way of a sworn Affidavit is required in all cases where a property is greater than one acre", while my local District Registry are a bit puzzled by my query and asked me to send them in the standard Estate Agent valuation I got, to see if it is acceptable. The EA was also puzzled as to how he would give me a sworn valuation, he is used to the Probate Office sending him forms to swear after applications were lodged, but had never heard of it being done before the application was submitted.
A tip that might be useful: while the Probate Registry will give you two CA24's to fill out, and swear, before returning them with the application; I find it best to also download and print one to practise on. I guarantee you will want to change mistaken entries.