They're tearing down walls to reveal history as a heritage restoration project in SoHo took a visible step forward on Friday.

The large archways in the former Horton Street railway roundhouse were revealed, a sight that's been hidden for decades.

It's a loud and messy process that's attracting a whole lot of positive attention.

For onlooker Wayne Salisbury it's a trip down memory lane, "When we were kids we used to come up here and unload bananas off the boxcar - 40 cents an hour."

For the first time in 70 years the archways in the original roundhouse can be seen.

The big reveal happened as demolition crews tore down the building built onto the back of the original steam engine service stop.

Don Menard, London's heritage planner, say an important part of the city's history is being recaptured.

"It was in danger of being demolished...The railway meant so much to this city back in the day in 1850s, 60s, 70s and even into the 20th century. We're now starting to see a building that really does capture how important a part of our history that really was. We don't have many other roundhouses left."

Built as a railway roundhouse in the 1880s, the building would eventually become a produce distribution centre and then a restaurant for the most of the last 40 years.

As much as possible of the building is being returned to its original specifications, the only difference being that it's going to have a high-tech infrastructure built in.

Creative Property Developments is transforming the building into office space and a pair of emerging tech companies were the first to sign on.

Spokesperson Roger Caranci says "It's great for SoHo. There's a lot more interest being created in SoHo because of this project."

He won't reveal the cost, but Caranci says the overall project is worth seven figures.

It's scheduled to be move-in ready by June.