Downtown Washington Inc. is renovating its former office building at the corner of Third and Jefferson streets into a guest house.

“It’s what we affectionately call the cabin and it is the oldest standing structure in Washington,” said Bridgette Epple, executive director.

The circa 1834 log house served as the downtown group’s office from about the mid-1990s to 2010 when the Downtown Washington Inc. moved just one block west to the old post office at Third and Lafayette streets.

The group is operating the post office as a CPU (contract postal unit) and has leased office space in the rear of the building.

The renovation to the cabin has been under way for some time, with all volunteer labor by Downtown Washington Inc. board members and supporters. Many local contractors and businesses also have pitched in, providing supplies or service as needed at no charge.

Epple hopes the downtown group can begin renting out the Gottfried’s Cabin Gast Haus later this summer. The one-bedroom guest house has a small kitchenette area with a microwave and refrigerator, a sitting area with a couch and another open area with a twin bed.

“It would probably best be suited for an individual or couple to rent, or possibly a family with one or two small children,” she said.

Epple said the guest house is named after G. Gottfried Beyreis, the man who built the log cabin.

Eileen Hagedorn will serve as the innkeeper, but all reservations will be booked through the downtown office.

“We hope to have the Gast Haus available by early August, in time for the Washington Fair,” Epple said.

“We’re excited to put this building back into use and have it be part of the downtown community,” she said. “The building is very old and needs a lot of care, so it’s not something we want to see get heavy daily use, like it did as our office.”

Epple said nearly all of the furniture and supplies to stock the house have been donated. A few items, such as bed linens and towels, are still needed, she said. Anyone with items to donate should call 636-239-1743.

The renovation, which is ongoing, has included shoring up the limestone foundation.

“The building was actually sinking a bit, but it has now been shored up and concrete poured,” Epple said. “A termite issue also has been addressed and there is no longer any wood touching the dirt.”

The existing bathroom has been expanded to include a shower and claw-foot tub, and the hardwood floors have been relaid and refinished. Some of the interior has been repainted and the exterior also will receive a new coat of paint.

“We’re really excited about this project,” Epple said. “It’s another opportunity for community investment and great utilization for one of our historic structures.”

Rick Hopp, former Downtown Washington Inc. board member who is now serving on the Historic Washington Foundation, the group’s sister organization, has helped to maintain the building since about 1992.

“The building worked great for the downtown office because of the location, but we have outgrown the space and it really needs a more gentler use today,” Hopp said. “I’m so excited more people will be able to enjoy it now as a guest house and that it’s now being used as it was originally intended — for living quarters.”