Hi John and Rory,
It wasn't actually the library I was talking about, but now you mention it, yes, I know it well - there are quite a few in that style (in fact, possibly the same blueprints) around Dublin - I know the one in Phibsboro, not sure how many more there are.
Anyway, the one I meant is I think the one Rory is talking about - it's right on the same road as the Telecom building (glass bricks... *drool*!!), closer to town. It's a huge building, very majestic. It's not an ESB substation though... I believe it's actually occupied by a company that deals with those funny square blue bins you find in the women's toilets (i.e. they incinerate "feminine hygiene products").
I've taken a few photos as a matter of fact, on the roll still in my camera, as soon as it's used up & developed I'll post them. By the way, does anyone have photos of the Adelphi before it was desecrated? The lower facade was clad with aluminium tiles, v. unusual and v. gorgeous. I wait for the bus everyday directly opposite it, it makes me ill to look at it now... I wish I'd managed to steal a few of those tiles before they destroyed it... I wonder if they kept them?