Commercial · rooftop shell

Your roof is the coldest thing you own.

A flat commercial roof spends every winter night radiating your heat at the sky, and every summer afternoon pushing it back in. The RoofPhab puts a glazed arch shell over it: a warm buffer in winter, a shaded chimney in summer, pre-heated intake air year-round — and an enclosed rooftop floor where there was nothing but membrane.

Run the payback → The revenue play instead

Where the savings come from

Four streams, and a fifth that usually decides it

We model each one separately so you — or your engineer — can argue with them one at a time instead of taking a single number on faith.

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1 · Winter solar buffer

The curved glazing collects low winter sun across a wide range of tilts and the plenum beneath it runs warm. A share of that heat migrates — or gets ducted — into the space below. It's the biggest single line in the model, and the least useful for demand charges, because it isn't there at night.

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2 · Roof heat loss, buffered

Your roof deck stops seeing −20 °C air and a clear night sky, and starts seeing a mild enclosed plenum. We credit about a third of the deck's seasonal conductive loss — a deliberately conservative fraction of what a warm buffer can do.

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3 · Pre-heated intake air

Code outdoor air is the load nobody optimises. Drawing it through the plenum instead of straight off the roof means it arrives already lifted — and on a high-ventilation building (restaurant, school, gym) this stream is larger than the solar one.

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4 · Summer, shaded and vented

The shell shades the deck it sits on and stack-vents its own heat out the crown, so the roof stops behaving like a radiator pointed at your air handlers. Cooling load and summer peak both come down.

The line on your bill nobody talks about

Demand charges, and why earth tubes carry them

A commercial bill isn't just kWh. A large share of it is billed demand — a charge on the single highest kW you drew, month after month. Shave the peak and you cut a charge that recurs whether or not you use another kilowatt-hour.

Here's the honest part: your winter peak happens in the dark. Solar contributes nothing at that hour, so we exclude it from the demand calculation entirely. What does work at 3 a.m. is the ground — earth tubes deliver intake air at about +9 °C when it's −21 °C outside, every hour of the year. That's why the packaged version of this retrofit shaves real kW and the shell alone shaves a little.

We also cap the claimed reduction at a third of your billed peak, because a single retrofit that claims to halve a building's demand is selling something.

How earth tubes work →

Earth tubes buried below frost line, tempering intake air

The fifth stream

You also get a floor

An enclosed, glazed, four-season space on top of a building you already own — a rooftop terrace that works in March, staff and amenity space, event or vendor space, a growing area. Roughly three quarters of the shell's footprint is usable floor; the outer edges are low-headroom where the arch springs from the deck.

This matters more than the energy story, and we'd rather say so plainly: at New Brunswick electricity prices, utility savings alone do not pay back a glazed shell in a commercial-sensible timeframe. Counting the floor it encloses, the numbers land where a building owner can act on them. The calculator shows you both figures, side by side, always.

See both numbers →

The rooftop shell from above: tables inside the enclosed glazed area, more out on the open deck, and a guard rail around the perimeter

Payback calculator

Run it on your roof

Building type sets the ventilation rate and roof assembly; the sliders set the shell. Put your own electricity rate and demand charge in — the defaults are New Brunswick estimates, not your tariff. Install cost is itemised, and payback runs on the ex-HST outlay because an HST-registered owner recovers the tax.

How it's built

A structural retrofit, engineered per building

The shell is a series of shop-built laminated arches on a reinforced roof structure, glazed in multiwall polycarbonate, curbed and flashed into your existing membrane. Repetitive arches are what keep a curved building from pricing like one.

Every commercial job starts with a structural review of what the roof can actually carry, plus the mechanical tie-in (plenum ducting, dampers, controls), hoisting access, and the code path. You get a sealed set per address — and an honest "not this building" when the structure or the access says so.

Have us review a building →

Structural model of the arch shell over a flat roof

One-pager

The RoofPhab sell sheet

One page: the four savings streams, the demand-charge argument, what it costs, and the payback maths — the version you forward to an owner or a finance committee.

📩 Email me the RoofPhab sheet

Planning-grade estimates, not a savings guarantee. Energy and demand outcomes depend on your building, tariff and operation, and every rooftop installation requires a sealed structural review of the actual building before anything is committed.