JUNEAU -- Juneau's skyline may become taller and denser as changes to area zoning codes require more densely built neighborhoods.

Recently approved changes are meant to increase the availability of affordable housing in Juneau, but the new rules may also alter the look and feel of some neighborhoods, the Juneau Empire reported.

Planners designed this increase in both density and height of Juneau's residential structures for one major purpose -- affordable housing, planner Greg Chaney said. The idea is to encourage affordable housing without creating regulation that requires building below-market-rate houses, condominiums and apartments, he said.

Housing is considered affordable if renters or owners spend 30 percent or less of their income on housing, including utilities, Chaney said.

Currently Juneau has a 3.2 percent vacancy rate for rentals and 1.4 percent for homeowner units, well below the national average.

Juneau's single-family home prices averaged a record high of $294,818 in 2011, including condominiums and "mother-in-laws."