Piece by piece: Off-site renovation There's something so fanciful about rooftop patios. Morning lattes, martinis at sunset, summer star-gazing, I could go on. But while these are all romantic notions, in reality my third-floor deck had become a repository for draught-ridden petunias and pigeon poop. What I really needed was space -- specifically, my own space, a master bedroom and en suite bathroom that provided both storage and solitude. Enter contractor, Matthew Costin of Englelake Ltd., in Oakville, Ont., who not only made my dream a reality but also spared me months of plaster dust and a seemingly ceaseless parade of tradespeople by doing most of the work off-site. His gang constructed modules that were air-lifted into place by crane on "delivery" day. A large-scale reno that is not conducted in situ is a new notion that's time has come (no more reno hell? Hallelujah!) and, as you can see, pre-fab has come a long way.1 The master bedroom's main dimensions (walls and floor) were constructed in my contractor's heated shop over the winter, when inclement weather brings most reno crews to a halt. Each one of the four walls and the wormed-maple floor (which will be stained on-site) is considered a single module; the modules get dropped into place one at a time by the crane and then snapped together like giant puzzle pieces.Next >> Piece by piece: Off-site renovation 2 Windows were installed ahead of time in two of the modules: the east- and south-facing walls. The east wall overlooks a park and we chose massive panes that are almost five feet in height. The result is a room with a treehouse-like quality.  3 We chose copper sheeting for the exterior of the walls, but whether copper, stucco or siding, the materials are all applied beforehand so that the units shipped are as close to fully finished as possible. Once locked in place on site, some roofing work was required to snugly seal all the joins.> Piece by piece: Off-site renovation 3 We chose copper sheeting for the exterior of the walls, but whether copper, stucco or siding, the materials are all applied beforehand so that the units shipped are as close to fully finished as possible. Once locked in place on site, some roofing work was required to snugly seal all the joins.> Piece by piece: Off-site renovation 4 Once the box (floor and walls) was constructed, I made bi-weekly visits to the shop to give my contractor the detailed information he needed to begin work on finishes: the dimensions of the shelves around the fireplace, the exact height of the built-in floating bed and the positioning of the electrical outlets. Even the paint shades were chosen well ahead of delivery date so a first coat could be applied. A second coat of paint was applied on-site. > Piece by piece: Off-site renovation 5 On delivery day, a giant crane and a truck pulled onto a side street two houses away from mine, much to the delight of the neighbourhood children who took turns sitting in the crane operator's seat. Two members of the crew were stationed in the truck, securing individual modules onto the end of the crane using an elaborate system of pulleys. The modules would be lifted over the backyards of two neighbouring houses and onto my own.>