Calgary’s City Hall has been under wraps since May 2017. The 1907 building is in need of modern upgrades
Witness to our history
One of our most familiar landmarks for more than a century, Historic City Hall has stood alongside Calgarians throughout our greatest victories and our hardest challenges including the Spanish flu of 1918 and two World Wars.
As Calgary navigates COVID-19 together, we are working towards the completion of Historic City Hall’s heritage rehabilitation and we are pleased to announce we’ve reached a significant milestone.
We’re ‘unwrapping’ Historic City Hall
Historic City Hall has been completely under wraps since May 2017, when it was surrounded by a heavy-duty protective enclosure.
Our exterior work is nearing completion and we no longer require the enclosure. We’re beginning the process of ‘unwrapping’ Historic City Hall and Calgarians will soon be able to view the building for the first time in three years! Said Darrel Bell Acting director.
While Historic City Hall was undergoing heritage restoration, the wrap covered the construction crew, equipment and materials, and protected the sandstone and exposed building components from weather. It allowed work to continue through every season regardless of extreme temperatures which was an important factor in meeting our project timelines. Underneath the wrap, the temperature remained a minimum 15 degrees Celsius, even if outside it was + or -30.
What are we going to see?
One of the most defining features of the building is its sandstone exterior.
When construction began on Historic City Hall in 1907, more than a dozen sandstone quarries lay within our current city limits. Hundreds of public, residential and commercial buildings from the time boasted local sandstone, and Historic City Hall is a beautiful example of Calgary’s late Sandstone City era.Oliver sandstone quarry, circa 1915. This quarry operated in the gully on either side of 17th Avenue SW. Courtesy Glenbow Archives
Of Historic City Hall’s 15,522 pieces of sandstone, 15,142 have received painstaking heritage treatment.
At the project outset, every stone on the building was individually mapped and prescribed a renewal regimen. The sandstone pieces were then rehabilitated one by one, with treatments including cleaning and structural fortification. Old sandstone that had deteriorated too greatly to be repaired was replaced with new sandstone. Approximately 2,400 new sandstone blocks were used. The sandstone blocks on Historic City Hall’s clock tower were individually mapped and prescribed rehabilitation methods.
“What Calgarians will see when Historic City Hall is unwrapped is a refreshed, rejuvenated version of the familiar landmark that has graced Calgary for more than a century,” says Darrel Bell, acting director of Facility Management. “The work we’ve done on the sandstone over the last three years has been a labour of love and has restored our sandstone to a condition set to last for another hundred years.”New sandstone blocks such as these pictured on the left were used to make repairs to century-old sandstone, such as that pictured on the right. 98% of the building’s 15,522 pieces of sandstone received treatment which could include cleaning, structural fortification or replacement.
Weathering…how sandstone tells a story
Calgary, Paris and Glasgow all have something in common: our heritage buildings all bear the mark of our unique pasts.
For instance, Glasgow’s centuries-old sandstone buildings have a patina that comes from the coal burning that took place every day over hundreds of years. Many of Paris’s limestone buildings wear damage from wars, or more ordinary things like damage from lack of maintenance or incompatible repair materials. Here in Calgary, Historic City Hall’s sandstone has been weathered by our harsh Prairie winters and sunlit summers.
The building’s new sandstone look alongside the stone that has acclimated for more than a century, for the most part, will have a minimal difference.
Replacement sandstone was very carefully selected to be visually and materially compatible with the original sandstone’s physical and chemical properties, composition, grain size, and colour.
Because sandstone is a natural commodity that is formed in the earth, it is full of character and can be found in a wide variety of colours including green, tan, red, pink and black. The project team worked diligently to place new stone in areas where its colour and appearance blended as seamlessly as possible with hundred-year-old stone.
Slight colour variations in the sandstone will exist on the building, just as it does in nature. While some new sandstone will initially look lighter in colour than existing stone, it will weather over time. Historic City Hall’s new sandstone is carefully chosen to blend with existing stone. The new sandstone is slightly lighter in colour, and it will weather over time.
“When we’re looking at a beach from the distance, the expanse of sand looks like one colour,” explains Bell. “However, when we scoop up a handful of that sand and look at it very closely, we can see that the grains are actually a wide range of colours and textures. We can think of Historic City Hall the same way: from a distance, the building will look the same uniform tan. However, when you view the building up close, you’ll notice that each sandstone block has its own subtle range of rich colour variations that are inherent to sandstone.”
The removal of the protective enclosure and scaffolding beneath it will be complete by the end of June.
We are working towards welcoming back Historic City Hall’s tenants at a time appropriate to the current pandemic. We’re excited to reintroduce this treasured heritage building in its revitalized condition, ready to stand for another century, said Bell.
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