The Worx Building was formerly the Monarch Building, a six-storey warehouse designed by Toronto architect C.H. Gibson in 1915. A good example of early 20th century industrial design, the building is constructed with load-bearing brick on a steel frame with timber purlins. The building is listed by Heritage Toronto as having architectural merit as it is an example of the characteristic materials, fenestration and classical organization and detailing of an early 20th century commercial warehouse.

Notable details, remarks Canadian Funding Corp, include marble floor tile and wall panels in the lobby and cut stone detailing at the main entry, sills and parapet. The existing exterior masonry wall (14″-27″) was exposed on the interior with no additional insulation. The old masonry construction was not airtight and the interior brick walls were found to include voids and rubble fill.

Previous uses of the building included light manufacturing, warehousing, clothing production, printing and design studios. The building occupancy rate gradually declined until, by 1996, only two floors were partially leased.

The developers’ goal was to provide innovative live-work one or two storey units ranging from 91 m2 to 167 m2 (980 ft.2 to 1,800 ft.2) this area close to the downtown core, the restaurant district, the Skydome and highway while offering a variety of unit designs within a historic building. The site was chosen for the historic aspect of the building, the potential for gated, surface parking, and its location on a street planted with mature trees and close to two parks, with limited through traffic.

The project was undertaken in 1997 after the King/Spadina Official Plan was put into place. The plan exempted this building conversion from density and coverage restrictions, and as a heritage building, it was exempt from parking requirements as well. A Heritage Easement Agreement gives additional development rights for long-term preservation of listed or designated structures. In this conversion, the construction of a new mezzanine structure on the roof was thus permitted. To satisfy municipal requirements, street improvements were necessary, including barrier-free access to the lowest building level, new landscaping, pedestrian-scale lighting, bicycle stands and new sidewalks with decorative stone trim.

There was no social housing mandate, funding or incentives for this site. Rent controls, high interest and property taxes limited private investment, but the City of Toronto’s “housing first” policy encouraged conversions. The main sustainable target was the preservation of the existing fabric, including the salvage of materials for reuse on site. Demolition of elevator shafts and new openings in exterior walls provided original bricks for reuse in filling openings of exposed interior wythes. New brick was matched for size to achieve consistent coursing-an exact match of colours was not found.

The initial design of the building mechanical system was based on individual, air- exchange heat pumps located at the exterior wall of each unit, but existing masonry spandrels and windowsills did not allow for this type of system. In the end, combination domestic hot water and individually metered space-heating boilers were leased by residents from the gas utility. Cooling capacity was provided by an air-cooled, liquid chiller installed on the open upper level of a service building located at grade. Common area HVAC systems introduced ventilation to entrance lobbies and corridors. Direct air leakage at window and door frames was addressed by the use of expanding foam sealants.

Acoustic measures for floors and demising walls were identified as an important concern to purchasers. The existing wood beams and decks were retained as a design feature, exposed to view from below as the ceiling of each unit. As a result, acoustic treatments could only be applied to the upper surface of the floor. Sheathing, acoustic underlay, polyethylene film and poured lightweight concrete were applied for acoustic insulation from floor to floor.

The typical demising wall includes two layers of 5/8″ gypsum wallboard on each side of the studs with 1/2″ resilient channels and 21/2″ acoustic batt insulation. The design rating of the assembly is STC 55. The acoustic consultant retained by the developer recommended this assembly, which exceeds OBC minimum requirements, in order to address acoustic issues identified by many purchasers in conversion projects. Brick masonry walls and timber decks are not monolithic, and will provide sound transmission paths that are difficult to seal if these materials remain exposed. An increased STC rating for demising walls does compensate to some extent for the flanking transmission that can be expected. The total thickness (mass) of gypsum wallboard panels was relied on to reduce acoustic transmission rather than varying the thickness of the panels.

Other measures undertaken to address acoustic transmission at partition edges include installation of compressed batt insulation at studs abutting the exterior masonry walls, as well as 7/16″, rigid fibreglass insulation at top tracks abutting the underside of the wood deck and at bottom tracks installed on a poured concrete topping. Fasteners for the perimeter studs and tracks were provided with steel and rubber washers to acoustically isolate the wall and floor assemblies.

Acoustic sealant was used to seal the perimeter of the interior layer of gypsum wallboard to the adjacent floor, wall and ceiling surfaces, and joint filler was used at the exterior layer to permit application of paint finishes.

Sales have indicated a strong demand for residential conversions that offer unconventional unit plans, have a historic character, provide parking, and are located close to the downtown core. The turnover rate has been approximately 10 per cent per year, and sale prices have increased at an annual rate ranging from 15 to 20 per cent. Purchasers could modify layouts and upgrade finishes and fixtures. A presentation centre and models were built to exhibit the upgrade options. Custom upgrades, as well as standard upgrades, were available. Thirty-three of thirty- four unit buyers chose upgrade options. In retrospect, the architect thought that the incorporation of purchaser revisions and upgrades was an enriching addition to the project.

Acknowldegments to CMHC.

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