Housing starts and building permits both rose in February. These numbers reflect growth in construction of multi-family homes, which would primarily be rental properties. Sales of existing and new homes also are at a year-long high according to January data. Demand for previously owned properties has also increased, cutting into the supply overhang from the 2008-2009 financial crisis.
Fixed-rate mortgages are at an all-time low of 3.87 percent. One of the goals of the Federal Reserve has been to keep such mortgage costs down in order to stimulate the housing market. To this end, the central bank has been swapping short-term securities for longer-term securities in order to help bring down borrowing costs in general (and thus also mortgage rates).