Boulder City, population 15,970, limits its growth by putting a cap on residential construction. But Las Vegas builder Wayne Laska sees little competition and has launched a 127-home project there. His development, Boulder Hills Estates, will span about 30 acres and is the biggest new housing tract in the city in decades. Home prices start around $410,000. By comparison, the median sales price of newly built homes in the Las Vegas Valley last year was about $383,700.