First in a weeklong series on housing.

The view from the back porch of Karen Smith's home in North Allston hasn't changed, but the feel of the neighborhood has.  It was once filled with families.  Kids hopped the backyard fence to play with friends.  Smith recalls what it was like when her son was growing up here.

"When the kids were little and running around, there were Saturdays when I probably made 13 peanut butter and jelly sandwiches for lunch, " recalls Smith. 

These days most of  the kids in Smith's neighborhood are "Millennials" - the generation of young people in their twenties and early thirties.  They are moving to Boston in record numbers for jobs and graduate school.   

"We're a great location for getting great places to work whether it's Cambridge, Boston, Watertown and Newton," said Smith.  "And its more affordable than other parts of the city.  Although, I think that's changing."

She's right.  Consider Ali Singer, a 27-year-old Northeastern University graduate who moved to Allston two years ago.

"The affordable place I could find was a four bedroom for, I think, $800 each," said Singer.  " That was our original rent and it's gone up a couple of hundred dollars."

The only way she an afford rent north of $3,000 a month, is to split the cost with roommates.

"One of my roommates is my brother," explained Singer.  "The other two roommates I met on Craigslist.  One of the girl's is like my best friend and the other guy is kind of weird and we don't really talk to him.  But it works."

That's how it's working, not just in Allston, but neighborhoods across the city.  Young people pool resources to make rent, but in the process, price out families.  

"It costs a lot of money to be to rent an apartment here," said Carol Ridge Martinez, executive director of the Allston Brighton Community Development Corporation.  

She says investors snap up homes for cash.  One example a triple decker for sale in Karen Smith's neighborhood.  The families living there pay $1500 a month.

"But when you go to buy it for $1.3 million, you can get twice as much - maybe $4,000 rent if you rent it out to young professionals, who will rent it out by the bedroom," explained Ridge Martinez.  She says the families who live there will likely leave the neighborhood. "They're not going to find any three bedrooms for $1500 in Allston Brighton."

Ridge Martinez says the young renters who will replace those families are less likely to be  invested in the neighborhood.

"If something's going on down the street that could be detrimental to the neighborhood, they don't really feel like they're part of the neighborhood or that they're going to be here for the long term," said Ridge Martinez.

Of course, young professionals help make the neighborhood vibrant.  One example, a community space called Pop Allston that includes, among other things, an indoor skateboard park.

Karen Smith welcomes her young neighbors, she just doubts they're here for the long haul.  Of course if they do decide to put down roots, they'll face the challenge of the families that once lived here:  finding a way to afford it.

For the rest of the WGBH News Block By Block Housing Project, go to