At this time of year, their home becomes a marvel of glistening lights and colourful decorations.
In their large garage, an extraordinary model train display features a bucolic village scene filled with snowy Christmas-themed activities.
Starting next week, the couple will once again open their home for people of all ages to enjoy the display.
While entry is free, they hope visitors will make a donation to support a solo mother living with muscular dystrophy, Lara Elliot, of Mosgiel.
Ms Elliot is striving to raise $30,000 to buy a wheelchair-accessible van, enabling her to share outings and experiences with her daughter.
The Smiths said reading about Ms Elliot’s story in the newspaper resonated deeply with the family due to the experience of their granddaughter Zoey Butcher, 5, who was diagnosed with spinal muscular atrophy and will eventually require a wheelchair.
Muscular dystrophy is similar to spinal muscular atrophy in that both involve muscle weakness and wasting.
"We thought, well, if we could help actually make a wee bit of a difference and get her out with her daughter," Mrs Smith said.
"It kind of rang a bell with us, I suppose, because of Zoey as well with everything she has gone through."
The festive display is a labour of love that takes over a month for the couple to set up.
This year, however, they had a more challenging task, because their garage was flooded during the large rain event earlier in the year.
The couple were on holiday in the United States at the time and returned to flood damage.
"It just came right through the garage, and of course everything was a bit mouldy and we had to take everything out," she said.
However, the couple turned the obstacle into an opportunity, clearing out the garage to create a huge model railway display that people could walk around.
"We don’t charge at the door," Mrs Smith said.
Ms Elliot said she felt as if she was dreaming when the Smiths contacted her about raising money on her behalf.
Through various fundraising efforts, she has secured about $21,000 so far to achieve her goal of buying a wheelchair-accessible van.
"I just can’t thank people enough.
"It doesn’t feel enough to me saying thank you or I appreciate it.
"But the tears do roll behind closed doors of how much I appreciate it."
Ms Elliot said she was very independent and was not someone who liked to ask for help.
"It means so much from my heart."
Her aim was simply to be able to spend time with her daughter Amelia, 8.
"She is an amazing daughter, really, she is just amazing.
"I’ve been stuck in four walls and I want to get out and make memories with my daughter because I feel she has missed out on quite a lot."
- By Sam Henderson
Open hours
The Smiths’ Christmas House
December 11-22.
Open 6.30pm until late.
13 Cutten St
South Dunedin