Perched on wooden pilings in Palo Alto's serene marshland, the Lucy Evans Baylands Interpretive Center is a celebration of nature -- a place where students learn about local bird species and where nesting barn swallows propagate.

But nature hasn't always been kind to this popular, 46-year-old attraction. Weatherworn and under-maintained, the wooden building off Embarcadero Road is showing signs of decay, with the trim around the roof now badly deteriorated and the wood on its siding and decking cracked and peeling in some sections, particularly those facing west.

"You can see ... that sun, wind, rain and birds have taken their tolls on both the siding and decking around the building," Tiffany Redding, the city's consultant from the firm FOG Studio, said during last week's meeting of the Parks and Recreation Commission, at which she showed slides of damaged wood.

Now, as the city is moving ahead with renovating the beloved building, the goal is to improve the facility without modifying its Baylands-friendly character. In the coming months, city officials plan to complete the design for rehabilitating and improving the Interpretive Center and obtain the needed work permits with the goal of launching construction in 2016.

The project, which also includes an upgrade to electrical systems and a redesign of the building's bathroom, has an estimated cost of $582,485. The City Council approved the expenditures last year, when it passed its capital budget for fiscal year 2016.

At the same time, the city is looking ahead to repairing the damaged boardwalk that rolls out from the building and overlooks the salt marsh. A recent analysis by the firm Biggs Cardosa determined that the boardwalk is in "serious condition," with several portions in need of urgent replacement or repair. While the sections of the boardwalk closest to and furthest from the center are in fairly decent shape, the firm found, the central portion was deemed to be badly damaged. Several elements in this portion have "failed," the firm determined, with several posts having broken off.

Staff has already done some basic repairs to the first overlook point, which has been closed off to the public since spring 2014. Last week, the 200 feet of the boardwalk nearest to the building was reopened to the public, said Darren Anderson, manager in the Community Services Department.

In the months ahead, staff, the Parks and Recreation Commission and, ultimately, the City Council will determine whether the boardwalk should be repaired, rehabilitated or replaced. Staff from the Community Services Department expects to see a council decision early next year.

Work on the building, meanwhile, should begin sooner than that. During the Oct. 27 presentation, Parks and Recreation commissioners and consultants from FOG Studio agreed to keep any changes subtle.

"The building right now fits well in with the Baylands, and I think that was the direction -- to keep a building that has that character," said Brandon Marshall, also of FOG Studio.

Even so, staff and FOG Studio are proposing some changes to the building. One is to reconfigure the bathroom, a project that will include a new "communal sink" to accommodate large groups of kids from a visiting class (according to the Community Services Department, the Interpretive Center and the adjacent Baylands serve about 129 classes and camps, 2,000 elementary students and 80,000 visitors annually). Another proposal is to add a transparent panel in the decking so that children and visitors of short stature will be able to see through the railing.

And the city is paying particularly close attention to the nesting swallows, whose droppings have been causing damage to the building's wooden interior. City staff have been mapping out popular nesting areas. The plan is to seal off these areas with soffit boards to both accommodate the swallows' preference and to limit the number of cavities in the building where swallows can establish their nests.

John Aiken, who oversees the interpretive exhibits at the Baylands center, said that in addition to increasing the city's control over where the nest colonies are, staff is also considering opening up areas of the deckings so that droppings can drop through.

"That has the double benefit of allowing kids to see down in the marsh and look under the building and notice that you're on the piers," Aiken told the commission. "It might be an interesting aspect."

The commission had mostly praise for all the work done to date on fixing up the aged building. Commissioner Ed Lauing praised staff and consultants for a "terrific effort on all the stuff relative to swallows."

"It's a lot of meticulous work on everyone's part to allow birds and people to live happily ever after," Lauing said.

Commissioners Deirdre Crommie and Abby Knopper agreed, with Crommie calling it a "really important project." At the same time, Crommie said she was concerned about the proposal to install a glass or plastic "vision panel," noting that such features often get dirty pretty quickly and suggesting that the city instead consider viewing slots in the deck.

Shani Kleinhaus, environmental advocate for the Santa Clara Valley Audubon Society, also praised the project and thanked the city for its efforts to keep the nesting swallows in the building. She recommended that any glass or plexiglass in the building be bird-friendly. This, she said, means adding subtle ceramic lines in the glass to help birds see the structure.

"I don't think it's a huge investment, but it's important to have that," Kleinhaus said.