I tweeted the other day that Paschal Taggart’s plan to build 40,000 homes — by developing 10 per cent of Dublin’s park land — was too small by an order of magnitude.  I’ll get to the details momentarily. But first I’d like to say my tweet was too harsh.  Taggart deserves credit for asking a very important question about housing. It’s one that doesn’t get raised enough.  Questions are often asked about who will build housing, how it will be built, in what quantity it will be built, what form it will take, and when it will be built.  There’s much less discussion over where it will all be built. Where is the hardest…