Dorchester is booming in ways unseen since our once sleepy agricultural hamlet was transformed into a teeming streetcar suburb before the turn of the 20th century. The growth is at once exhilarating and troublesome and that tension is likely to be a central theme of the upcoming mayoral election cycle.

Boston’s building boom is further bolstering the city’s financial standing and borrowing power.

Last year, according to the State House News Service, new development added a whopping $4.3 billion to the city’s taxable valuation. A large majority of that new growth— 60 percent— was seen in residential properties.

Large projects in the Seaport District, Southie, and downtown have absorbed much of the new units, but now it’s quite obvious that Dorchester’s main streets and side roads have become the sweet spot for builders.

Overall, that’s a welcome change.

We particularly encourage the Walsh administration’s outstanding initiatives to re-develop long-vacant city-owned lots on more than 250 scattered sites throughout Dorchester and Mattapan. The Neighborhood Homes Initiative (NHI) now includes 73 units under construction, with another 45 slated for start-dates later this year.

The program is particularly welcome because it engages existing residents early on in the design of the new homes – primarily single and two-family residences – that are then marketed to qualified first-time home buyers through the Boston Home Center. Ensuring that these new buildings fit in with the surrounding housing stock and — especially on these residential side streets— is a sensible and worthwhile endeavor.

We hope that members of the city administration and the Zoning Board of Appeals will take a cue from the Dept. of Neighborhood Development as they consider the myriad of private projects that come before that city board seeking exemptions from codes regulating height, density, and parking.

There is growing anxiety that the administration’s willingness to approve higher-density build-outs on parcels previously restricted to single or two and three-family properties is getting out of hand.

As reported last week, the ZBA’s decision to approve a developer’s proposal to raze a single-family house on Fuller Street near Ashmont station and replace it with six multi-bedroom apartments has raised alarms across Dorchester’s civic circuit. Such a dramatic expansion in density at this site is out of character with the surrounding homes, leading neighbors to worry that it will lead to unbridled speculation that could cascade across the side streets around Ashmont.

Shelly Goehring, a longtime civic leader who lives in Ashmont, noted that the decision “sets a precedent that tearing down single-family houses, protected by zoning, is okay by the ZBA. Sadly, realtors take note.”

As Bill Walczak, a well-respected civic leader from Savin Hill and a 2013 mayoral candidate, noted in a discussion about this issue at the Columbia-Savin Hill Civic Association last week, such decisions create “a perverse incentive to demolish single-family houses.” He added: “You could obviously get more money for a single-family house that could be redeveloped as an apartment building.”

Dorchester is shouldering its fair share of large-scale new developments from Ashmont and South Bay and Glover’s Corner to Uphams Corner. Civic leaders, by and large, have grasped the opportunity to work with developers and city planners to embrace growth rather than take an obstructionist stance.

This cooperative nature should not be abused.

City leaders and zoning members should seek to preserve the distinctive character of streets like Fuller Street and discourage the conversions of single- or two-family houses into larger complexes.

We’d like to see the city’s housing policy follow the example of the Neighborhood Homes Initiative. Bring on the housing, but do it in a way that is more respectful of existing neighbors and with an eye toward curbing unreasonable density that will forever change the character of our community.