The National Association of Home Builders' housing market index rose 1 point in June, to 77, after a 6-point jump in May.
June's score is the second-highest ever,, just under the 78 recorded in November and December.
The association said builders expressed concern over the shortage of skilled construction workers and building materials such as gypsum wallboard, insulation, and brick. The availability of building lots was also a concern in many markets.
The index for current sales of single-family homes rose 4 points, to 85, and the index of builders' expectation of single-family home sales in the next six months rose 2 points, to 84.