Advantages of holding Irish passport over uk passport- residing in spain.

Irish passport holders are classed as EU citizens and don't need a visa nor a work permit to come and live and work in Spain.

You do need to register on the foreign EU citizens living in Spain and will be liable to the same income tax regime as anyone else.

The same health care is available and you will get free healthcare if you are the holder of an S1 or working in Spain and paying into the social security system. If not, you will need to show proof of private medical insurance but the financial means are just 1xIPREM (600 euro a month) rather than 4xIPREM required by a non-EU citizen.

Rental tax is charged differently. Non EU citizens pay 24% of the rental income but EU citizens will pay at the same rate as their income tax levels from 19% up.

You also don't have the time restrictions on leaving Spain even though Ireland is not in the Schengen area and you don't get your passport stamped on entry and exit. 

You are still restricted to a maximum of 90 days as a tourist but this can be extended by signing on the register and, once in Spain more than 6 months in one calendar you, will be classed as a tax paying resident.

regarding the income - so as an EU passport holder I only need to show 7200 euro (600x12) in the bank so to speak instead of 28800 euro a uk passport holder (non EU), is that 7200 for each or jointly?

It's 600 euro per month for the first applicant and around 3000 a year for anyone else in the household but those figures are regionally dependent, not a national requirement and can change.

There is an official page on the IPREM 

Proof of income in the form of bank statements, pension income etc must be officially translated into Spanish and show all your personal details. You would also be required to show these payments into a Spanish bank account for 3 months before applying.

Thanks ,thats great info about having funds in account 3 months funds prior to application.

so we would only need to show about 11000 euro in funds in a Spanish account.- thats good news