With gantry cranes sprouting like spring dandelions, it’s hard to miss: There’s a lot of construction going on downtown. An estimated $3.5 billion in downtown construction projects are now under construction or in design.

Many of these new buildings are tall by local standards. At least four new buildings over 20 stories are being planned. And, thanks to the Wasatch Front’s rapidly growing population, this trend will continue and intensify. Like a teenager’s downy mustache, downtown’s increasing density is a sign of approaching maturity.

This trend is healthy and inevitable. Like sharks, cities must move forward or suffocate. Unlike sharks, they must evolve and adapt to changing economic and social conditions. Like all changes, increasing density has good and bad aspects. On the plus side, the construction boom itself is a powerful economic engine, creating thousands of construction jobs. Higher density provides more workplaces, homes and hotel rooms for people who in turn support local businesses and enhance downtown’s vitality. Higher density also makes the city as a whole more sustainable, reducing sprawl, making public transit more effective and increasing walkability.

Greater density also brings challenges. These can be effectively addressed through good building design. The quality of the design of new buildings and the spaces between them will determine whether increasing density enhances or diminishes the livability and sustainability of our downtown core. Some key points:

• Open space. One of the most important aspects of any building is the space it creates around itself on the ground. Our downtown core is woefully short of public open space. Developers of new downtown buildings should be given incentives to create lively, green spaces where people can have lunch with a friend or just relax for a few minutes. Such small, shady public spaces provide a welcome respite from busy street life and enhance the livability of the city.

• Street scale. The buildings lining a street can make it feel like a pleasant place to stroll or something out of Maze Runner. It’s not only a question of their height. There’s an unfortunate tendency for contemporary tall buildings to spring straight up from the ground to their full height, with little variation above the ground floor, which may contain entrances and storefronts. The street walls of such buildings should step back to create a well-proportioned street space, allow more sun to reach the street and create visual variety. At a minimum, changes in wall materials should define the scale of the street.

• Sustainability. Building design greatly impacts Salt Lake City’s goal of becoming more sustainable. Buildings account for about 40% of the country’s total energy consumption. Making new buildings more efficient — as well as retrofitting existing ones — can go a long way towards decreasing our energy consumption and carbon footprint. Good design is especially important for taller buildings which typically consume two-and-a-half times as much electricity and 40% more natural gas per square foot than buildings of six stories or less.

One current trend in tall building design is at odds with this goal: a fondness for glass walls. In our climate, a glass façade is like the proverbial screen door in a submarine. Technology and good design can improve the performance of glass walls to some extent, but these measures (assuming they’re taken) provide only a partial remedy. Glass façades are simply not appropriate in our climate.

• Preservation. Finally, we must preserve our past as we march boldly into the future. By raising the value of the land underneath them, increasing density can make older buildings tempting opportunities for redevelopment. While we have regulations protecting historic buildings and groups like Preservation Utah that monitor projects that may threaten them, residents’ involvement is also needed to ensure that our historic architecture- our collective memory- is not lost.

How a city builds is a reflection of its values. As residents, our involvement in all aspects of planning and designing our city’s future is essential. Public bodies such as the Planning Commission, the Historic Landmarks Commission, the Planning Division and community councils offer many opportunities for each of us to help ensure that, as our city matures, it becomes a more humane, sustainable place to live.

David Ross Scheer, Salt Lake City, has practiced and taught architecture and urban planning for over 30 years.