What it is

Three moves, one transformation

Most peaked roofs cap the house with a large volume of unused attic. The RoofPhab reclaims it — swapping the pitch for a flat, engineered roof you can actually live on, topped with the solar-passive Sophab Arch grown into a greenhouse.

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1 · Lose the peak

We remove the pitched roof and the wasted attic beneath it, and cap the house with an engineered flat roof built to carry real live load — people, plantings and snow.

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2 · Gain a floor

That flat roof becomes usable space — a rooftop terrace, a top-floor room, a garden deck — adding square footage without buying more land or pushing out your living walls.

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3 · Crown it with a GreenPhab

A curved, glazed greenhouse on top grows food through every season and acts as a solar cap, warming the whole home beneath it.

Two configurations

Crown part of the roof, or all of it

Same three moves either way — the difference is how much of the new roof you put under glass. Both are cut away here to show the stair coming up from inside the house.

Cutaway of a RoofPhab: a stair climbs from the new top floor onto a flat roof deck, with a GreenPhab greenhouse over part of the roof and open deck around it

Cutaway of a fully-enclosed RoofPhab: the arch spans the whole roof, with a stair climbing from the new top floor into the glazed volume

Counter-intuitive, but true: the partly-glazed option is the harder build.

Wherever glass meets open deck, wind piles snow into a drift against the glazing and the curved roof sheds its own snow into the same spot. That strip of deck can see two to three times the load of the open field, right where you'd want raised beds. The fully-enclosed arch has no internal step, so it has no internal drift. Expect the open-deck version to cost more per square foot, not less — and expect us to tell you where the beds can go.

Open new doors

A whole new level, from wasted volume

An attic is space you paid for and can't really use. The RoofPhab turns it into the best room in the house — up in the light, with a view — plus an open rooftop deck around the greenhouse to sit, garden and gather.

It's one of the few ways to add a full level to a home without buying more land or pushing out the walls.

See it on your home →

Grow & heat, from one roof

Food up top, warmth down below

The GreenPhab crown is a four-season greenhouse — start seedlings, grow through winter, and keep a rooftop garden going on captured solar heat. Pair it with earth tubes and it holds frost-free with almost no active energy.

The glazed cap also works as a solar collector for the house. Heat doesn't fall downstairs on its own — warm air stratifies at the top of the glass, which is exactly where you'd lose it — so we duct it: a small fan pulls the hot air off the crown and delivers it into the house below, and reverses in summer to dump heat before the greenhouse cooks.

We won't quote you an energy saving we haven't modelled.

A big glazed volume is a solar collector by day and a heat loss by night — a glass cap insulates far worse than the attic it replaced. Whether your house comes out ahead over a full year depends on your climate, orientation, glazing spec and how the transfer loop is run. That's a modelling exercise we do for your address, not a slogan.

How the GreenPhab works →

A four-season greenhouse crowning a converted flat roof

How it's built

A structural retrofit — engineered and stamped

The RoofPhab changes the structure of your home, so it's an engineered job, not a weekend project. We replace the roof framing with a flat deck rated for live load, waterproof and insulate it, and set a GreenPhab — the Sophab Arch, tuned for growing — on top.

This is a Part 4 engineered design, not a job the code's span tables cover, so every RoofPhab comes with a set sealed by an engineer licensed in your province. Expect a pre-application meeting with your building department too: New Brunswick's code isn't applied retroactively, but substantial alterations give the reviewer room to ask for other upgrades — egress windows, alarms, stair geometry — so we'd rather find that out before you're committed than after.

Every RoofPhab starts with a structural check: it's best for homes where the attic is wasted volume and the load can get cleanly to the ground. We'll tell you honestly whether your house is a good candidate — including when the answer is no.

See how we help →

Structural model of a flat-roof conversion with a rooftop greenhouse

Carrying the weight

We don't ask your old walls to do a new job

A roof you can walk on carries fifteen to thirty-five times what your ceiling joists were designed for. The honest way to handle that isn't to reinforce a sixty-year-old house from the inside — it's to give the new level its own legs.

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An outside frame

New footings below frost line at the corners and along the long walls, carrying posts that take the whole new level — deck, greenhouse, snow and all — straight to the ground. Dug from outside with a machine, not by hand in your finished basement.

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A floor that clear-spans

Open-web floor trusses span wall to wall inside the deck build-up, so there's no beam hanging into your ceiling and no new posts landing in the middle of your rooms. The open webs also give the roof drains, ducts and wiring somewhere to run now the attic is gone.

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Thrust that goes nowhere

An arch pushes outward at its feet. We land the springs over the frame posts and tie opposite posts together through the deck, so the arch resolves its own push instead of shoving on top plates that were never detailed to take it.

Built before the roof comes off

The frame goes up while your house is still dry and closed. That shortens the window where your home is open to the sky to the strip-and-deck stage — the difference between a nervous month and a nervous week, and a much smaller temporary-roof bill.

Your eaves come back

Flat roofs usually cost you your overhangs, and overhangs are what keep rain off your walls and windows. Because the deck reaches out to the frame posts, it oversails the walls and hands that protection back.

Not every house needs the frame — and it isn't free.

Sound concrete foundations, 2×6 walls and a bearing wall that stacks properly can often carry the new level directly, and then an outside frame is money and yard for nothing. But the posts and footings do sit just outside your walls, which grows your footprint on paper — so on a narrow lot they have to be checked against your side-yard setback before anything else. We work out which route your house takes at the structural check, not after.

The numbers, for Fredericton

What a roof you can live on actually has to hold

People assume flattening a roof piles on snow load. It mostly doesn't — snow is measured on the flat either way, and a shingled roof under 30° gets no credit for its slope. What changes is what's underneath it, and what happens at the glass.

3.1kPa

Ground snow load for Fredericton under the National Building Code

64psf

Design load across the open deck — snow governs, so the "people and furniture" load rides along free

160psf

At the drift line where the greenhouse meets open deck — about 2.5× the open field

0.35kPa

What your existing ceiling joists were designed for. There is no version of this where they get reused

The other number that surprises people is soil. Saturated rooftop growing medium runs about 1,500 kg per cubic metre — a foot of it in a raised bed weighs more than the entire design snow load. That's why planter positions get fixed in the engineering set rather than left to wherever the beds look nice.

Figures above are scoping numbers for a typical Fredericton house, worked from NBC 2015 Part 4. Your sealed set carries the values calculated for your address, roof size and configuration, and those are the ones that govern.

Straight talk

What can stop a RoofPhab at your address

We'd rather lose the sale in week one than in month four with your roof off. These are the things we check first, and any one of them can end it.

📏 Height limits

Residential zones in Fredericton cap building height at 9 m. Losing the peak actually buys you room — but a 2.5 m greenhouse on top can put you back over it. Sometimes that's a variance, which means a public process, neighbour notification and months. It can also mean no.

🏛️ Heritage areas

If your home sits in a heritage preservation area, taking off a pitched roof and putting glass where it was will not be approved. This is a fast, free thing to check and we check it before anything else.

🧱 Your foundation

Stone or rubble foundations, common in the older core, generally can't take this on and neither can new footings placed beside them without care. Sound concrete is a green light; anything else needs a hard look.

🪚 Trusses vs. rafters

Truss roofs clear-span the whole house, which means there's no bearing wall under your attic and nothing in the middle to build on. It's workable — that's what the outside frame and clear-span trusses are for — but it changes the price.

🪟 How close the neighbours are

A wall of glass near a property line runs into the code's limits on unprotected openings. On a narrow lot that can cap how much of the new level goes under glass on that side, which may rule out the fully-enclosed option.

☣️ What's in your attic

Pre-1990 homes may have vermiculite insulation, which is often asbestos-contaminated. It has to be abated by specialists before the roof opens — commonly $4,000–$10,000+ — and it's far better found by a test now than by a crew mid-demolition.

🏚️ You'll likely need to move out

For part of the job there is no roof, which means no heat and no upstairs bathroom. Plan on six to ten weeks away for most builds, and budget accommodation as part of the real cost. Tell your insurer too — most homeowner policies have renovation and vacancy exclusions, so you'll want a course-of-construction policy in place.

💰 It is not the cheapest square footage

Structural work of this kind runs in the range of a second-storey addition — roughly $375–$550 per square foot in Canada right now, plus 10–20% in permits and engineering, and a RoofPhab can sit above that band because of the engineered deck, the waterproofing and the custom glazing. If you only want more enclosed rooms, a conventional addition is cheaper per foot. What it can't give you is a four-season growing space on your roof, no change to your living footprint, and a solar cap on the whole house.

And the part nobody can quote around: we can't see inside your walls.

Stud grade, footing depth, whether that upstairs partition is actually carrying anything — none of it is knowable until something is opened up. That's why a RoofPhab starts with a paid structural investigation rather than a firm price. Anyone handing you a fixed quote for this work off a drive-by is either padding it heavily or about to come back for more.

Living with it

What owning a roof deck asks of you

A peaked roof sheds water and snow by itself, forever, with nothing to maintain. Trading that away for a level of living space is a good trade for a lot of people — but it is a trade, and you should hear it from us before you sign.

❄️ Snow comes off by hand

The deck and the glass both have limits, and a heavy winter will reach them. Clearing is an owner job on a membrane that a steel shovel or an ice chipper will puncture — so we spec the tools, mark the no-go zones and put it in your handover documents. Snow sliding off the curved glass gets a designed landing spot, away from the door and the seating.

💧 Waterproofing is a wear item

The membrane under everything lasts 20–30 years. The greenhouse is meant to last longer, so we build the arch to come apart and keep the membrane under it reachable — otherwise re-roofing means dismantling a greenhouse, and that bill lands on whoever owns the house then. Ask any flat-roof builder how they handle this; if they haven't thought about it, walk.

🌫️ Humidity has to be managed

Without an attic, a flat roof can't dry out — anything that gets into the assembly stays there. With a warm, wet greenhouse above and a heated house below, that assembly is under pressure from both sides. It's why we air-seal to a tested standard, put the insulation above the deck, and design where the condensation off the glass goes.

🧊 Drains that don't freeze

Flat roofs in our winters melt from below and refreeze at the edges, damming water on the membrane. Drains get routed inside the warm envelope, overflow scuppers go in as a second line, and discharge is aimed somewhere that won't become an ice sheet across your walk or your neighbour's lot.

🛡️ Guards, glass and getting up there

A rooftop deck needs a 1,070 mm guard all round, overhead glazing over occupied space has to be laminated safety glass, and a code stair has to come up from inside — which costs you floor area on the storey below. All of it is in the sealed set.

📉 It may not appraise for what it cost

Appraisers don't always credit rooftop deck and greenhouse area as living space, and some insurers price flat roofs higher or decline them. Worth a call to your broker and your lender before you commit, and we'd rather you make that call early.

Turn your roof into a floor.