Jill and Landon Haug agree it's been hard to leave their baby Britynn’s side after her life-saving heart surgery on Feb. 3, just a week into her life.

Donations to the Ronald McDonald House of Ann Arbor, including a $100,000 gift from Southwest Airlines last week, will allow families like the Haugs to be even closer to children undergoing serious medical procedures at the new children’s hospital.

A new, 12-room wing of the Ronald McDonald House of Ann Arbor will be opening in the fall as part of the $754 million University of Michigan C.S. Mott Children's and Von Voigtlander Women's Hospitals complex constructed adjacent to the U-M hospital. It will be on the 10th floor in the pediatric intensive care unit, said Kim Kelly, executive director for Ronald McDonald House of Ann Arbor at 1600 Washington Heights.

The new house and the hospitals are set to open in November, Kelly said. A $1 million contribution from the Mott Children’s Classic golf outing held in June also funded the Ronald McDonald House expansion, along with support from the University of Michigan Health System. The global charity with chapters in 52 countries runs almost entirely on donations, Kelly said.

The Ronald McDonald House of Ann Arbor is separate from the hospital. Since it opened 25 years ago, it’s almost always been at capacity and is in high demand, Kelly said. The current house has spots for 29 families.

The new wing will be intended for short-term stays for families with the most critically ill children in the pediatric intensive care unit.

“Hopefully they will be able to rotate over to the existing house,” Kelly said.

To stay at a Ronald McDonald House, families need to live at least 40 miles away from the hospital and have a child undergoing treatment who is under 21. Ronald McDonald House asks for a $10-a-night donation, but families are never turned away if they can’t pay. Familes have stayed at the house for as long as nine months, Kelly said.

The Haugs said they've been staying at Ronald McDonald House of Ann Arbor for about six weeks. They drove 1,000 miles from South Dakota to deliver their daughter at Mott via C-section on Jan. 25. Brittyn’s congenital, which means present at birth, heart condition had been detected at her mother's 20-week ultrasound.

Like most families who stay at Ann Arbor's Ronald McDonald House, the Haugs are here so their child can receive care at Mott’s renowned U-M Congenital Heart Center. Congenital heart defects affect almost one of every 100 births and are the leading cause of infant death in the United States, according to nonprofit The Children's Heart Foundation.

Cardiac surgeon Richard Ohye performed Brittyn Haug’s surgery on Feb. 3 to correct a condition called hypoplastic left heart syndrome, Jill Haug said. The condition means parts of Brittyn’s heart were underdeveloped at birth and were unable to properly send blood throughout the body. If left untreated, the condition is fatal. Britynn will under go three surgeries at Mott in the first year of her life to fix her heart.

Amid the stress of the birth, surgery and being away from the couple's three young boys for weeks, Jill Haug said the Ronald McDonald House has taken financial stress off the family as they wait for their baby to recover. The parents are on unpaid medical leave as Britynn receives treatment.

Sara Hickey, the administrative manager at Mott, said the new, in-house partnership the expansion will bring is an extension of a long, close and beneficial relationship with Ronald McDonald House of Ann Arbor.

“Even through they’re separate organizations, it almost seems like they're one," she said. "We work so closely together, and both benefit from each other’s presence.”

Juliana Keeping is a health and environment reporter for AnnArbor.com. Reach her at julianakeeping@annarbor.com or 734-623-2528. Follow Juliana Keeping on Twitter