The television cameras and film crew may have made it obvious, but the 35 students in Civil and Environmental Engineering Prof. Martin Fischer’s “Maintaining Sustainable Building Projects” class knew something unusual was afoot as they shuffled into the 8:30 a.m. class yesterday morning.

E-mail correspondences from Fischer days prior to the event implored students to arrive to class on time, since it would be taught by a guest lecturer — renowned architect and designer William McDonough. What the unassuming students didn’t know, but soon found out, was that their lecture was to be led by not one but two guest speakers — including actress Cameron Diaz.

Diaz surprised the class as part of mtvU’s “Stand In” television series, in which celebrities and public figures act as guest professors and teach classes on subjects about which they are passionate. Yesterday, Diaz and McDonough discussed the sustainable building movement and other civil engineering ideas aimed to protect the environment.

“I love the environment,” Diaz said. “It’s something I feel very strongly about. I’m a consumer and have everything I’ve always wanted, so I’ve looked into ways to consume without being damaging to the environment. And I came across the sustainable movement.”

Opening with a “Hi, I’m Cameron,” accompanied by her initial trademark laugh and a “smarty pants” comment after McDonough praised Stanford’s reputation, Diaz took on the dual role of moderator and motivator, leading discussions among students and entreating them to harness their creative energies to achieve a greater good.

“What are you guys going to do?” she asked the class. “How far are you going to take it?”

McDonough, who is currently serving as a consulting professor of civil and environmental engineering at Stanford, shared with the class his visions of a green, utopian world and expressed his hopes for the future.

“We are living in a tragic state of design, where the world gets worse and worse instead of getting better,” he said. “We’re getting more efficient, but we’re wasting our natural resources. So why not start now and create products with environmentally-sound design? It’s your generation, so let’s create buildings which are ‘more good’ and not ‘less bad.’”

Diaz also emphasized the important role students can play as proponents of sustainable design, even on a small scale.

“You always hear the comment about wanting to leave a big footprint in the sands of time, but it can be a small footprint too,” she said. “It doesn’t need to be bigger, just better. You guys can definitely be doing these things. And it’s very exciting. This [sustainability] is a great challenge for our generation.”

Students said they were largely impressed with Diaz’s genuine interest in environmentalism and were surprised that she could lecture on the subject at Stanford.

“The event was really amazing, and I was very impressed by Diaz,” said sophomore Fareez Giga. “I was impressed more so by how she actually came to campus to talk about sustainability. She provided a lot of good information, especially because I was not as familiar with some of the concepts, and so I definitely learned a lot.”

“We had no idea at all that something like this would happen,” added Alexandrah Govere, a sophomore. “We kept getting e-mails from Prof. Fischer telling us to be here on time, but we had no clue that Cameron Diaz would be here. She brought up a lot of good points, especially how instead of making things ‘less bad,’ we should be working to make things ‘more good.’”

However, some, such as senior Christina Liebner, felt that the discussion was superficial since many in the class already supported the idea of sustainability.

“The issue is very important to us, and I felt like they were not presenting any new ideas, but rather almost preaching to the choir,” she said. “It was very much like a pep talk, and I wish they talked more about specifics and finding ways to be more sustainable, instead of just telling us to be sustainable.”

Still, Liebner said she found the lecture to be worthwhile.

“It was pretty broad, but it was good for people who aren’t as familiar with the concepts or haven’t heard the arguments before,” she said.

Fischer also said he was pleased with the outcome of the lecture.

“It will definitely raise awareness of these issues to a broad audience,” he said. “We did not get into specifics, but I will probably try to bring Bill [McDonough] back for a follow-up session. I do hope that all the students leave with the question in their minds of how to design things better.”

In an interview with The Daily, Diaz remarked on the importance of reaching out to the college crowd.

“This is my first time speaking on a college campus, and I like the idea of speaking to college students because they are so enthusiastic,” she said. “You guys have such a great influence, which you can share with other people. Good luck!”

The episode of “Stand In” will premiere on mtvU’s broadband network, mtvU Uber, on Tuesday, Nov. 1.