A group that's advising the $10 million revamping of the Minneapolis Sculpture Garden is opting toward crossing its 16th-century formality with 21st-century sustainability.

That means reinforcing the formality of the garden's south end and leaving the garden's signature Spoonbridge and Cherry where it is. But it also means adding a wilder-appearing area at the garden's north end for both artwork and stormwater, and some potentially radical changes for the heat-leaking glass conservatory.

The proposed new look for the north end would create three grassed circles with radii ranging from 45 to 75 feet in the midst of an area that will be sometimes wet, sometimes dry as runoff dictates. Stormwater handling improvements in the boggy area bring up to $1.5 million in watershed funding to supplement $8.5 million the Legislature appropriated for the renovation.

But the conservatory is likely to get a new look. Changes there could range from mere improvements to existing features such as bathrooms and floors to removing the walls and heat from throughout the energy-inefficient building.

Among the recommended changes from landscape architecture consultant Oslund and Associates and Snow Kreilich Architects are new entry ports around the garden. The west side, now a parking lot, could get a school and tour bus dropoff area, with staging space for events. The north side could get a clearer entry off neighboring Dunwoody Boulevard. Bus riders on Lyndale Avenue would get a stairway at the southeast corner to replace cowpaths they've worn. Pedestrians would get two ramps leading down from the Lyndale sidewalk through a hillside of floppy fescue grass.

The more formal south entrance would retain a central stairway but it will be flanked by accessibility ramps. It would lead to granite slabs recycled from elsewhere in the garden. More durable granite chips would replace the crushed limestone that's proven dusty as it crumbles. Other areas would keep sidewalks for wheelchair access and to support cranes needed to install artwork.

The southernmost and most formal of the garden's spaces would have its formality reinforced with a series of changes that include strengthening its north-south and east-west axes. The four quads of that more 16th Century formality would be emphasized with rows of linden trees, plus ornamental grasses and trimmable euonymus, a shrub known for its corky flanged bark and flaming autumn foliage.

Some of the high-traffic areas will get a more engineered base under the grass that uses sand and fabric in an effort to make the turf more resilient.

Project manager Dana Murdoch said the design concept now will be refined for a final meeting of the citizen advisory committee that's scheduled for Feb. 23 from 6:30-9:30 p.m.at Walker Art Center.

Fitting all those changes into the project budget will be challenging, representatives of the project team warned the advisory committee convened by the Minneapolis Park and Recreation Board, which is working on the design with Walker Art Center. "It's a series of choices," committee Chair Margaret Anderson Kelliher said. "Some things may be done in the short term and others may have to wait."