The Engineered Gingerbread House

The inspiration for this gingerbread house came from a project we were involved in a few years ago: renovation of a cold institutional former youth detention centre to a warm, inviting visitor reception centre at Echo Valley Provincial Park, Saskatchewan. The architectural design was completed by Jessica Gibson and Roger Mitchell. I completed the structural engineering. While all of the façade was replaced, the main exterior architectural feature was a large circular concrete platform with a winding ramp intended to act as not just an accessible feature, but also a journey, flanked with a corten wall with the topography of the Echo Valley etched into it. Providing sunshade and height to the building is a large cantilevering pergola. To the side, there is a privacy screen made of steel tubing intended to mimic local native grasses.

Like all good gingerbread houses, this one started off with a sketchup model. From that model, I was able to pull out scaled components to print and use as patterns. After the dough was prepared and chilled, all the pieces were cut out and baked.

The first issue encountered during construction was caused by a lack of surveying. The size of the site (a large wood cutting board) was not taken into account, and the building would not fit. Due to this serious lapse in judgement, the building size was cut in half.

Next, site work was undertaken. The actual site slopes downward from the building into the parking lot. In order to recreate this, the building elevation was built up graham wafers and icing. Graham wafers and icing were also used construct the concrete platform, stairs, and ramp.

The walls of the building were constructed of 20 full-size Kitkat bars and grouted together with melted white chocolate. This allowed for mimicking of the hardiboard siding without excessive icing. Not considered in the original design was the bevelled edges of Kitkat bars, which led to rotating every second bar to face backward. The cedar siding detail was illustrated with yellow smarties.

The roof and eaves are comprised of pre-decorated gingerbread.

Once the building was complete, it was finally time to move onto the most challenging component: the cantilevering gingerbread pergola!

The larger beams were comprised of laminated gingerbread complete with a 3-strand twizzler inset to mimic the knife connections of the real deal. Again, white chocolate was used to laminate the beams. Initially, 7 beams were constructed to reflect the 7 beams of the actual building.

The column was constructed as a built-up gingerbread column laminated with white chocolate. Thick Hersey jersey milk bearing plates were cut into the built-up column and reinforced with additional jersey milk plates welded together with additional white chocolate. The platform was excavated to allow the column to bear on solid ground, and the column was grouted in place.

Next, temporary shoring was constructed out of graham wafers and individual Kitkat bar plies. This shoring provided the bearing necessary to place the beams, weld them in place, and allow the white chocolate to set. At this stage, it was identified that the bearing plates were not large enough to support 7 beams, and two were removed from the design. Once set, the remainder of the column was built up, the cables were put in place, and the last ply of the column was held in place with twine until the white chocolate set. Once set, the shoring was removed, exhibiting the cantilevering pergola in all its glory.

Lastly, final exterior elements were added such as the pretzel guard rails, the pretzel privacy wall, and the Lindt decorative screen at the ramp. Licorice was used to demark the step and ramp edges for the visually impaired. Sporadic wildflowers popped up at the perimeter of the building. Finally, the building was opened to the public and several gingerbread men visited on opening day.

Structural materials were not tested prior to construction. The structure is being monitored for evidence of movement or potential failure.