Sky Lantern shines bright in Vancouver

Home to the Vancouver’s financial and central business district, West Georgia Street is replete with architectural monuments and landmark buildings. But as Sean McGowan discovered, the addition of a visually stunning and high- performing office tower is set to shine a new light on the city’s skyline.

Established in 1992, Westbank Corp. is one of North America’s leading property developers.

Boasting more than $25 billion of projects completed or under development in Canada, the US and Japan, Westbank is well known for its collaboration with some of the world’s leading architects. Its practice has been built around long-term commitments to artistry, sustainability and city-building.

If that doesn’t sound like your typical property developer, then seeing is believing.

Westbank’s latest project in downtown Vancouver, 410 West Georgia, is envisioned as a living sculpture. Designed by Japanese architectural firm OSO, with local architects Merrick Architecture, the 25-storey commercial office tower’s design is inspired by a Japanese lantern, with a series of staggered, steel-framed cubes arranged around a central concrete core.

Each cube … has been designed and positioned to create natural compartments within a continuous floorplate

Currently under construction, the 34,135m² of office space will feature glass floors overlooking the city, vertical gardens framing views to the mountains, roof terraces and the largest rooftop amenity in Vancouver.

Internally, the work space is designed to be open, flexible and diverse so as to encourage collaboration, creativity and spontaneity among its tenants.

Each cube – itself four storeys high – has been designed and positioned to create natural compartments within a continuous floorplate. The floors and ceilings of the cantilevered portions are glazed to visually link the gardens, offices and street below with views that are both horizontal and vertical.

“Designed to both reflect nature and to honour its surrounding environment, 410 West Georgia will create a unique and constantly changing experience for all who encounter it,” says Westbank Corp. project manager, Nathaniel Funk.

Not just skin deep

As well as pushing the boundaries of architecture and construction, the building has been designed to a LEED Platinum standard – the highest tier offered by the US Green Building Council’s green building certification program. This rating is the equivalent of 6 star Green Star, or world leadership status.

And central to this has been the design of a decentralised HVAC system by mechanical services consultant, Norman Disney & Young (NDY) – a Tetra Tech company.

Contracted by Westbank under a design-build agreement along with local mechanical and plumbing contractor, Broadway Omega, NDY commenced work on the project in February 2018.

“One of Westbank’s main objectives was to develop innovative commercial office space together with a flexible and optimised mechanical system capable of meeting the demands of the next-generation office space, and achieving LEED Platinum performance,” says NDY associate and market sector leader, Charles Duffy.

The complex steel structure of the building, which supports the cantilevered and rotating floorplates, posed significant spatial challenges for the mechanical services designers, and pushed the design away from a centralised approach. This would typically see large air risers installed through the core.

“We had to look to a floor-by-floor plant solution when it came to ventilation and air conditioning, which similarly posed some challenges in regards to tempering outside air whilst meeting the LEED Platinum targets, and maintaining net lettable area (NLA),” says Duffy.

Working closely with both the OSO team from Japan, and Merrick Architecture locally, NDY has participated in weekly collaboration meetings, workshops and conference calls to ensure the design is both coordinated and workable.

Duffy says many of the building’s architectural elements have had a significant impact on the mechanical and plumbing systems – some not immediately obvious without the close collaboration of the design team.

For example, discharging exhaust air behind the vertical gardens that will adorn the building’s façade posed a number of challenges, including the potential for icing in the Canadian climate.

“The relationships we have built between ourselves, the mechanical contractor Broadway Omega, the architects, the general contractor in Ellis Don and the client, Westbank, have become very important over the course of the project as challenges emerge,” says Duffy.

“Allowing time for close coordination across the various stakeholders is proving to save a lot of time during construction, with reduced requests for information (RFIs) and changes.”

Space at a premium

According to NDY’s Charles Duffy, the relative scarcity of premium office space in downtown Vancouver means serious attention was placed on maximising the rentable floor space within the 410 West Georgia building.

“This was one of the key drivers in moving from mechanical plantrooms on each floor, which take up NLA, to separate in-ceiling ERVs that typically serve the six separate floor zones,” he says.

Additionally, Duffy says running large ducts across the floorplate from a single location was not an option, with the deep structural beams integral to the architectural design.

“With multiple ERVs, we could keep the ductwork depth to a minimum and maintain the required ceiling heights across the office floorplates.”

Careful arrangement

The HVAC design employed at 410 West Georgia combines a highly efficient chilled water system with supplementary heating hot water supplied by one of the Vancouver’s district energy systems.

To overcome the spatial constraints and architectural complexity of the steel cube building structure, NDY has carefully selected four-pipe fan coil units (FCUs) that fit between the structural beams. These are fitted with six-way valves in order to obtain increased capacity out of these smaller units.

Their arrangement was carefully considered to ensure that floors were appropriately zoned with sufficient capacity for future tenants.

The FCUs are served by a modular chiller design that enables a high level of redundancy and serviceability with minimal loss in capacity, and allows for low-load plant operation at high efficiencies.

“Fan coil units generally offer relatively quiet performance and the level of local control that is sought by perspective tenants,” says Duffy.

“And when paired with the modular chillers, this chilled water/heating hot water-based system offered both the high efficiency required for the targeted LEED Platinum credits, as well as appropriate staging and redundancy that tenants are looking for.”

Each office floorplate within the building typically features six distinct sections that make up the stacked-cube arrangement. Each has been provided with an energy-recovery ventilator (ERV) to serve its respective section.

Coupled to the FCUs, the ERVs on each floor are used to efficiently introduce the required outside air to the office space in order to meet both Code and the air quality and energy performance requirements of the LEED Platinum standard.

The ERV equipment has been selected to not only fit within the ceiling structure, but also to successfully couple with MERV 13 filtration – the minimum efficiency reporting value designed by ASHRAE to rate the effectiveness of filters. This design has allowed the building to significantly reduce energy consumption without compromising on air quality or NLA.

“One of the benefits of this arrangement is that tenants have multiple access points to filtered supplementary outside air and general exhaust via the ERVs dispersed across the floorplate,” says Duffy.

Of course, with benefits also come challenges, and the use of ERVs on the 410 West Georgia project has been no different.

For instance, the only locations available for intake and exhaust air were found to be behind architectural, perforated mesh screens.

This meant that environmental conditions and humidity levels needed to be carefully investigated and considered to ensure the potential for ice build-up at the façade was mitigated.

Sky Lantern Office, 410 West George

A consultant abroad

After joining NDY in 2017 as a member of the Asset Performance team specialising in delivering modernisation and performance improvement solutions for existing buildings, Charles Duffy transferred to the NDY Vancouver, Canada office in January 2018.

There, he leads the interiors team, as well as the team working on 410 West Georgia.

“It has been a whirlwind journey for me between Melbourne and here in Van,” says Duffy.

As an Australian consultant working abroad, he says while the fundamentals of mechanical engineering remain the same in Canada as in Australia, there are some interesting climatic differences to overcome – as well as local regulations to understand and consider.

“As well as considering humidity levels of exhaust air at the façade, so as to avoid the formation of ice at the building surface, dealing with snow build-up is a standard part of design here that is encountered much less frequently in Australia,” he says.

“In a similar vein, heating is a far more dominant consideration in façade zones, parkades (carparks), entrance ramps and the like. There are very real life-safety risks to heating systems failing in winter.”

Duffy says Vancouver has multiple district energy systems that new buildings may or may not be required to connect to for their heating requirements.

“This comes down to the targeted energy credits and allowances under the local by-laws,” he says.

Under construction

NDY and Westbank’s goal to deliver a uniquely designed building within specific budgetary constraints has been achieved, with 410 West Georgia currently under construction and set for completion in 2020.

“410 West Georgia is on track to achieving a LEED Platinum certification, which will deliver improved standards of energy performance, better air quality, reduced environmental impact and increased daylight for occupant wellbeing,” says Duffy.

Such is the anticipation of this project that it has attracted a number of high-profile tenants.

The Vancouver headquarters of Deloitte Canada has been announced as the anchor tenant of the new office tower and is set to occupy almost 11,000m² of space within the top 10 floors of the building.

Tech giant Apple and Amsterdam-based co-working company Spaces have also been reported to be other key tenants.

Lessons from the consultant

NDY associate and market sector leader, Charles Duffy, shares three lessons from the firm’s involvement in the 410 Georgia Street project.

1. Pick up the phone. A lot of time is wasted with emails and RFIs when a phone conversation is often all that is needed.

2. Work closely with the structural engineers early, and ensure they attend coordination meetings.

3. Know your equipment and maintenance zones. Draw them in, at the very least, on a detail.

Sky Lantern Office Interior, 410 West George

Project at a glance

 

THE PERSONNEL

Architecture: OSO Design + Merrick Architecture
Client and owner: Westbank Projects Corp.
General contractor: Ellis Don
Mechanical services consultant: NDY – a Tetra Tech Company
Mechanical services contractor: Broadway Refrigeration & Air Conditioning / Omega Mechanical

THE EQUIPMENT

AHUs: Engineered Air
BMS: DDC
Chillers: Climate Master
Controls: Olympic Controls
Diffusers: E.H. Price
ERV: RenewAire
Fans: Twin City
FCUs: IEC
Fluid cooler: Evapco
Grilles: E.H. Price
Heat exchangers: Taco
Pumps: Taco

 

(Source: NDY)

This article first appeared in Ecolibrium magazine: https://www.airah.org.au/Content_Files/EcoLibrium/2019/06-19-Eco-001.pdf

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