THE ROTUNDA

High-performance office building rejuvenates downtown neighbourhood

Occupying a prominent downtown corner across from Victoria’s historic City Hall, this mixed-use commercial complex includes two levels of underground parking, a street level with landscaped boulevards and public plazas flanked by ground floor retail spaces. The six-storey, 10,362 m² west building and 13-storey, 16,299 m² east building house class-A office space above.

By Franc D’Ambrosio, Founding Principal, Erica Sangster, Principal, D’AMBROSIO architecture + urbanism and Andy Chong, Managing Principal, INTEGRAL GROUP.

Urban Design and Architecture

The developer’s aim was to contribute to the resurgence of Victoria’s downtown, provide much needed high-quality office space and set a design benchmark in the regeneration of a moribund city block. The building forms have been sculpted to define street edges and create public spaces that are welcoming, human scaled, and integrated with both the street fabric and the building activity.

The fundamental massing strategy was to divide the site laterally and thereby locate two separate and distinct buildings. As a complex of two buildings, the project is in scale with the surrounding context. The separation has allowed for gracious public open spaces and also facilitated phased construction. The two buildings share aspects of form and materials, but differ in their massing and façade composition. Both outwardly express their function, with slender office wings and primary circulation routes clearly articulated in concrete and glass.

The public focus of the project is the Rotunda, a 500m² sky-lit atrium that brings natural light into the centre of the west building and also functions as the return air plenum for the ventilation system. To support the 20-metre diameter skylight, a unique structure comprising six ‘boomerang-shaped’ radially arranged, glue-laminated timber members was designed. The members are connected with steel tension rods, as well as concentric steel tension and compression rings – a solution that is economical in material use and maximizes daylight penetration.

Energy

The project’s Energy Utilization Intensity (EUI) was reduced by high-performance in three main areas: building envelope; ventilation heat recovery; and building heating and cooling. Building envelope options were optimized using energy modelling, and include a continuous layer of exterior insulation to achieve R-30 in walls.

Combined with high-performance double-glazing and a strategic window-to-wall ratio, the building enclosure minimizes both heat loss, and cooling requirements due to solar heat gains.

Heating and cooling for the building is driven by a hybrid air/ground-source heat-recovery chiller plant. This system can operate in either air-source mode (taking advantage of Victoria’s relatively temperate climate), or in ground-source (maintaining compressor efficiency, while using only a modestly-sized borehole field). Radiant ceiling panels provide heating and cooling to all office spaces, using moderate water temperatures and eliminating the need for fans to distribute space heating and cooling.

Ventilation

The larger east building uses underfloor air distribution and displacement ventilation. Dual core heat recovery technology reverses intake and exhaust pathways every 60 seconds, alternately charging large aluminum cores to achieve more than 80% effective heat recovery; much higher than conventional fixed-plate or wheel-type systems.

Variable speed AHU fans and automatic VAV dampers modulate the supply of dedicated ventilation air (no recirculation) in response to CO2 and humidity levels, maintaining indoor air quality and exhausting latent heat gains, while conserving energy for fans, heating, and dehumidification. All systems are controlled by a comprehensive digital Building Automation System.

PROJECT PERFORMANCE

Energy Intensity = 102 kWh/m²-yr
Thermal Energy Demand Intensity = 22.9 kWh/m²-yr
Energy Consumption Reduction vs. ASHRAE 90.1-2007 (LEED 2009) Baseline = 45%
Energy Cost Savings vs. ASHRAE 90.1-2007 (LEED 2009) Baseline = 33%

PROJECT CREDITS

Owner/Developer: Jawl Properties
Architect: D’Ambrosio Architecture + Urbanism
General Contractor / Construction Manager: Campbell Construction
Energy Model: Integral Group
Structural Engineer: RJC Engineers
Building Envelope: RDH
Landscape Architect: Murdoch & de Greeff
Electrical Engineer: AES
Mechanical Engineer Integral Group
Structural Engineer: RJC Engineers
LEED Consultant: Integral Group
Photos: Sama Jim Canzian

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January 3, 2020March 7, 2020

UBC AQUATIC CENTRE

Advanced sustainable design strategies improve performance in this challenging building type

Completed In 2017, this 8000m² hybrid competition and community aquatic facility replaces an aging indoor and outdoor pool complex, no longer capable of meeting the University of British Columbia’s changing needs. The challenge was to create a facility that would balance the high-performance training requirements of the university successful competitive swim program, with the increased demand for lessons and leisure opportunities from the rapidly expanding residential communities on campus.

By Jim Taggart

The Aquatic Centre is divided north south into four linear program ‘bars’ – lobby and change rooms, community aquatics, competition aquatics, and bleachers. Daylight is used to differentiate between the two aquatic halls. A line of Y-shaped columns supports a continuous six-metre wide skylight that bisects the aquatic hall, delineating competition and leisure areas. A translucent screen creates a luminescent barrier between the two principal spaces, making it possible to control the uses, and have two different activities or events taking place simultaneously.

The architectural composition consists of three distinct elements: a tessellated standing seam metal roof that hovers over an inclined black concrete base, and is separated from it by a continuous ribbon of fritted glazing. The roof rises and falls according to the functional requirements of the spaces below, its slopes and projections providing rain protection, solar shading, and control of daylight penetration as required. The building has become an integral part of the university’s new student hub, adjacent to the bus loop and a few steps from the new student union building.

As a building type, aquatic centres present some major challenges from the sustainability perspective, including water conservation, air quality, energy optimization, light control and acoustic performance.

Water Conservation

Of these, water conservation is the most significant, standard practice being that pools are emptied and the water discarded every time the pool requires maintenance. For the project team, not only did this seem an outdated practice from an environmental point of view, it also seemed incompatible with UBC’s reputation as a leading proponent of sustainable design.

In fact, water conservation has been an important consideration for the UBC Properties Trust for two decades, with new buildings now required to reduce water consumption by 30% relative to the reference standard. This is part of an overall requirement that all new projects are built to LEED Gold standard.

With the university currently conducting research on regenerative neighbourhoods, the project team began looking for ways in which the building could contribute positively to the infrastructure requirements of the community as a whole.

The answer was to create an underground cistern that could not only collect all the pool water during maintenance, but also supply the fire department should the need arise, or accommodate storm surge water for the north campus precinct, so relieving pressure on the existing storm sewer system.

The cistern, which has a capacity of 900,000 litres, is divided into three compartments according to the amount of filtration required prior to reuse. Another of its functions is to collect rainwater from the roof and the adjacent transit plaza, reusing it for toilet flushing, irrigation and poll top up.