The ISEQ 20, an index of the biggest Irish listed companies, is down 25 per cent since the start of the current crisis. Yet the two biggest house builders, Glenveagh and Cairn Homes, are down 40 and 45 per cent.  In a country with a crippling housing shortage, why have home builders been hit particularly hard? How is the coronavirus crisis filtering down to builders and landlords? And how worried should homeowners be? “Unprecedented” Last week, we got the first detailed estimate of what the coronavirus will cost the country, when the Economic and Social Research Institute (ESRI) released its…