Try something like this...
Dear sir or madam,
My name is Rena, and I would like a grant for a studio in the vicinity of Barcelona. I have only been able to study the beautiful landscapes of Barcelona from afar, as I live in Australia. I am now eager and willing to do whatever it takes to secure a flat in the Barcelona area so that I may paint the magnificent scenery that Barcelona has to offer, possibly offering original paintings at no charge for display in any of the city offices that the municipal would see fit.
I think that many people are into flattery, and everybody is into free stuff. Instead of thinking about what they can get you( although that is the point of the letter) perhaps think about what you can offer them in return. Possibly offering free originals or a weekly community art class where the city may collect any moneys received. Tell them why it would benefit them to grant you this flat.
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Heut ist mein tag