Three years before the Farnsworth House was built, its drawings and a model were the centerpiece of an exhibition at the Museum of Modern Art in New York. On display at MoMA in 1947, the model inspired a then youthful architect, Philip Johnson, to design and build his now famous “glass house” in Connecticut. But the Farnsworth House, intended as a weekend retreat for a Chicago internist, Dr. Edith Farnsworth, was and is the genuine article — a seminal work of architecture designed (and built) by a towering figure of 20th century architecture, Ludwig Mies van der Rohe.

Now a museum, it is owned by the National Trust for Historic Preservation and managed by the Landmarks Preservation Council of Illinois, which took control of the building in a Sotheby’s auction in 2003 for $7.5 million. In the custody of true preservationists, every piece of the building — which is so simple looking as to leave an observer wondering how difficult it would be to preserve a structure that is mostly glass, steel and marble — has been analyzed with an eye toward building a long-term schedule of restoration and preservation.

Whitney French, who manages the site for the Landmarks Preservation Council, says the schedule includes a complete rebuilding of the distinctive travertine marble decks, which are composed of several layers of gravel and porous vermiculite sandwiched between the tiles and a frame of precast concrete and steel. At issue, drains located underneath the outdoor decks have long since corroded and have become clogged. Basically, the decks need to be taken apart and rebuilt.

Other parts and systems of the home are also slated for various grant funded projects. A flat roof, which Mies designed, drained to the middle and down through the center core of the house. A reroofing during the 1970s increased the grade toward the center so as to evacuate the water more quickly. Now preservation experts are at odds over which roof to replace. A new roof is clearly needed, but two camps of preservationists face a choice — leave the current leak-free solution in place or return to the design of the master, which was also leak-free but worrisome to many because the grade is likely not enough to handle a true Midwestern gully-washer.

“One camp feels that every part of the original should be restored, including the roof, which is not part of the visual experience,” notes French. “The other school of thought is to keep the current type of roofing solution in place, even though it is not the original design, because it is doing a good job of protecting the rest of the structure.

“These are the types of debates that the preservation community has when it makes decisions about Farnsworth House and other important buildings,” French explains.

Among a number of other long-term projects that are also slated for action is to reduce pressure on some parts of the glass walls. Parts of the distinctive steel framework are pushing on two of the mammoth floor-to-ceiling panes of glass. The pressure is coming from steel mullions that have warped as a result of condensation. This project will require new custom-made mullions built to original specifications. Then there is the more routine care for the gleaming white steel frame. Every so often, the steel frame must be sandblasted. Then workers must apply the same three layers of coatings and finish paints as those used in 1950.

Inside, there is considerable debate about preservation of the primavera veneered “core” of the living space. Parts of the wood veneers that cover the kitchen, living room and bedroom areas of the home have suffered water damage from past floods. The quandary for preservationists is that replacing two slightly warped bathroom doors at either end of the core would reveal differences in the shading of the wood that comes only with age. New veneer doors would have a slightly lighter color than the rest of the core, thus diminishing the visual effect of the pure slab of wood color intended by Mies.

An interesting side note regarding this core (as the center functional structure is often called) is that some of the building products came from companies that are still in business today. While it is true that most of the original wood work was constructed by a local craftsman, Carl Friend, the kitchen cabinets were custom-made by St. Charles Cabinetry, which is now owned by Viking Corp. Additionally, a huge 17-ft. stainless steel countertop with basin was constructed by Elkay Mfg. Co., complete with spots for cooktop burners to come through. Both of these items are original to the house and do not require any restoration work.

The flood of 2008

All ongoing preservation schedules were literally washed away in September 2008, when the adjacent Fox River rose above the 5-ft. 3-in.-high steel stilts upon which the home sits. It was the third time that a flood had washed over its main level since it was built. In 1956, the home was overrun by several inches of water. In 1996 a devastating flood saw water from the river rise to over 4 ft. inside the home. This time it was only several inches over the main floor, but enough to do considerable damage. Repair and restoration costs related purely to the latest incident will be $500,000 and $600,000 to properly restore, says French.

Because of the long timelines involved in grant requests and subsequently issuing requests for proposals (RFPs) from a specialized group of architects and contractors and then fielding their responses, the restoration work from the flood of 2008 will not begin in earnest until later this spring.

French is hoping that the estimated damage amounts, most of which will be covered by insurance, will be enough to cover the actual expenses. As an example, French mentioned the estimates of replacing the drywall located inside the cramped mechanical room. Because of the tightness of the space, all of the mechanical equipment must be removed before the drywall can be replaced. One estimate for this job alone is $40,000.

There is always a concern, says French, whether the amounts will be enough to attract the interest of the cadre of architect/builder preservationists who are at the top of the preservation field. The hours of research required can be very high. Among this group is Harboe Architects of Chicago led by Gunny Harboe, AIA. Firms also mentioned by French include Harry Hunderman of Wiss, Janney and Elstner Associates, Mark Sexton or even Al Novickas, who, along with Mies’ grandson Dirk Lohan, have been intimately involved in the preservation efforts of the home to date. To this small group of preservation specialists each decision, however minor, is worthy of analysis and discussion.