Business Week magazine this week rated Boulder the strongest housing market in the United States.

The rating was based on the fact that Boulder saw less impact from the burst housing bubble than most places, has sen many years of steady growth in values and has a stable employment base with the University of Colorado and large federal science labs.

However, the thousands of acres of protected open space that ring the city and limit the supply of housing add up to one of the biggest factors in the city’s strong housing market, the magazine concludes.