New residential construction - the barometer of Manteca’s economic health since the start of the first building boom in the 1970s - dipped slightly in 2012.There were 282 single family homes either built or started last year. That’s down from 313 in 2011. Overall - when the 152-unit Juniper Apartment complex is tossed into the mix - Manteca started 465 housing units in 2011 Manteca in 2012 recorded its third straight year of the value of overall construction activity hovering between $75 million and $80 million.