Be careful where you walk these days, lest you bump into a backhoe.

Yesterday’s empty lot is now sprouting bricks.

And it seems that every time you sneeze, there’s a groundbreaking.

In case you haven’t noticed it yet, the campus is in the middle of the biggest building boom since the 1960s. And like the previous binge, this one will also produce a dramatically different Penn.

Some of the changes are already evident. Along Walnut Street, for instance, the recently completed Sansom Common and Annenberg School projects have continued the street-reclamation project begun with 3401 Walnut. And Huntsman Hall should continue the street reclamation one block further west.

But these projects are only the tip of the iceberg. More than $660 million in projects are either under way, on the drawing boards or recently completed. Here’s a scorecard, based on information provided by the Office of the Executive Vice President and Facilities Services:

Annenberg School: Complete. This $15 million project created a Walnut Street front door for the school, revamped the library and classrooms and added space to house the Annenberg Public Policy Center.

Addams Fine Arts Hall: Under way. James M. Skinner Hall, the Faculty Club’s former home, will become the new home for the Fine Arts program in the Graduate School of Fine Arts in July 2000 at a cost of $5.2 million.

College Hall: The rebuilding of the east wing is now under way. The $9 million project, part of the ongoing reconstruction of Penn’s oldest building, will be complete by next Labor Day.

Civic Center site: Demolition of Exhibition Hall and Center Hall is scheduled to begin by year’s end; no word yet on what will replace them. Penn and the Children’s Hospital of Philadelphia should break ground by January on a $21 million, 1,800-car garage at University Ave. and Civic Center Blvd.

Dental House: Complete. An Osage Avenue apartment building with a seedy reputation received a $2.2 million makeover and is now home to 40 School of Dental Medicine students.

General Electric building: Dranoff Properties begins work this week on a two-year, $55 million project to turn the building into 250 apartments, retail and office space and parking for 250 cars.

Hamilton Square: A concrete slab — the foundation for the parking garage and supermarket, and site of this year’s Beaux Arts Ball. Foundation work begins this week on the Sundance Cinemas, the centerpiece of this $35 million project set to open next spring.

Hamilton Village: A gleam in the eyes of the architects, who have been asked to design new low-rise courtyard dormitories and reconfigure Hamilton College House as two separate college houses.

Jon M. Huntsman Hall: A hole in the ground. The Wharton School’s new $128 million classroom/office/student-center building is on track for completion in the fall of 2002.

<Melvine J. and Claire Levine Hall: A parking lot. By early 2002, it will be a new $15.2 million building, the second phase of the Institute for Advanced Science and Technology, linking the Towne Building with the Moore Building’s Graduate Research Wing. Groundbreaking is set for next summer.

Murphy Field: The new 1,000-seat, $2 million home for Penn’s baseball and softball teams is now rising on the banks of the Schuylkill, along with a new $61 million chilled-water plant next door.

Perelman Quadrangle: The $82 million campus student center is nearing the halfway point. The Terrace Room and Fox Student Art Gallery in Logan Hall opened last year, and the Silfen Student Study Center in Williams Hall and the restored Irvine Auditorium opened this month. The Penn Commons outdoor plaza should be finished by mid-January; a rebuilt Houston Hall should open in May.

Pottruck Health and Fitness Center: Work on this $20 million project to expand and renovate Gimbel Gymnasium is set to begin after Commencement next year.

The Quadrangle: One summer down, three to go for the $75 million rehab-and-reconstruction pro-ject designed to bring Penn’s oldest dormitory up-to-date and carve it into three college houses.

Robert Schattner Center: You can already make out the basement of the Dental School’s new public gateway, a $22.8 million building set to open next fall.

Silverman Hall: The exterior restoration of the Law School’s landmark 1900 structure should be finished next month; the entire $11 million remodeling job should be finished next fall.

3401 Chestnut: Penn will take title to the parking lot Nov. 1, but no start date has yet been set for the office/laboratory/housing/retail facility planned for the site (last estimate: $100 million).

In addition, University City Associates, Penn’s commercial real estate arm, is in the midst of a $3 million remodeling project on its larger properties, set for completion next spring.