"I'm full of crazy ideas": monolithic dome taking shape in Sudbury.

• Author: Kelly, Lindsay
• Position: DESIGN-BUILD

As Jeremy Mahood stands inside what will eventually be the new All Nations Church, he muses about other applications for similarly styled buildings: arena, golf course, salt storage, house, soccer pitch, equipment storage. Now that the design team is well on its way to constructing the first monolithic dome in Northern Ontario, the possibilities for future uses seem endless.

"I'm full of crazy ideas," laughs Mahood, All Nations' senior pastor. "The brain never stops."

Crazy? No. Innovative? Definitely.

Nothing about the church's construction has been conventional, at least by Northern Ontario standards. Construction has taken place from the outside in, following standard monolithic dome building methods; the structure was put up before the water, wastewater and sewer were installed; and the church is being constructed on a pay-as-you-go basis--there is no loan or mortgage tied to the building. And then there's the monolithic dome design.

Measuring 11,000 square feet, the concrete thin-shell structure was erected over three months last summer by South Industries of Menan, Idaho. Construction began with a 10-foot-high circular concrete base, to which a waterproof membrane was attached and inflated using air pressure.

"This building was pumped full of air at about two pounds per square foot more than the outside air which is enough to keep the roof inflated, and while it's inflated, they spray the foam," Mahood explains.

The polystyrene foam insulation was followed by a layer of rebar which was then followed by a layer of specially formulated shotcrete, made by Rainbow Concrete. Fireproof, rot-proof and hurricane-proof, the 3.5-storey building has an expected 300-year lifespan and is LEED-platinum certified. All this was done at a cost of roughly $76 per square foot.

"I'm not sure that you can build LEED-certified platinum out of other materials for that amount of money," Mahood says. "So anyone who's interested in sustainability and longevity, and minimizing the impact of their utility costs, this kind of building should start to get on their radar"

A monolithic dome's value comes from its low maintenance, high energy-efficiency and flexible floor plan. Although it's not known how acid rain will affect the outer membrane, it should last 35 to 40 years, Mahood says.

Because of its design and materials, energy costs of the dome will be roughly 50 per cent of those of a...