Something interesting hit my desk recently: a glossy fundraising brochure from the National Trust for Historic Preservation, which is trying to raise money for the Philip Johnson Glass House in New Canaan, Conn. By all accounts the house has proved to be a remarkable success in its new life as a museum, which goes to show the value of preserving modern architecture.

But Johnson and his late partner, the collector David Whitney, left the Glass House estate in less-than-pristine condition. So the trust sent out its brochure, designed by Michael Bierut of Pentagram, as a wish list of projects that require funding. Each initiative comes with a price tag, from $10,000 toward the conservation of Johnson's Nicholas Poussin painting, Burial of Phocion, to $500,000 toward the purchase of an adjacent parcel of land, to prevent the construction of McMansions that would spoil the view. (As thanks, donors get to take curator-led tours and such. You can download the document at www.philipjohnsonglasshouse.org.)

For my money, the most intriguing item on the list is a project called the Materials Innovation Study. A $10,000 donation will support an investigation of 12 of the 90-odd modern houses around New Canaan built by some of the great innovators of the day, including Marcel Breuer, John Johansen, and Eliot Noyes. Like their counterparts across the country, these architects conducted remarkable experiments in design and construction, using untried materials and methods; now researchers will conduct field tests to understand how the components have performed over time.

In a sense, Johnson's generation did its job too well. Innovation entails risk. Many modern buildings, including structures at the Glass House, have weathered poorly. One worthwhile outcome of the trust's study will be a set of conservation guidelines for use in modernist landmarks throughout the United States. Our generation has inherited a responsibility to document the modernist experiment in architecture?and to preserve the results of that experiment for posterity as best we can.