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high performance building

Interview with Graeme Stewart of ERA Architects

Graeme Stewart is a principal of ERA Architects which was the lead architect of the Ken Soble Tower transformation, one of the largest EnerPHit-certified projects in the world. www.eraarch.ca

1. How did ERA Architects become involved in the Ken Soble Tower project?

ERA Architects had been working for over a decade on the Tower Renewal Project, a strategy for the revitalization of Canada’s aging postwar apartment neighbourhoods, through which we gained experience on tower retrofits. As part of the Hamilton City Housing portfolio of buildings, the Ken Soble Tower was in a distressed, abandoned condition. Based on our experience, we were brought in to do an assessment of what to do: tear it down or retrofit.

2. Deciding to do an EnerPHit transformation was a bold decision. How did you arrive there?

I am pleased to say that the decision was largely made for us by Hamilton City Housing CEO Tom Hunter. He came from the health care sector and said that we build world-class hospitals and need to do the same for our public housing. He understood the long-term benefits of doing an EnerPHit transformation, and the project moved ahead from there.

3. Once the project was a go, how did the process work of coordinating the various disciplines in the team?

When Hamilton City Housing decided on pursuing EnerPHit the intent from the start was to achieve certification. This kept everyone ‘honest’. It was crucial to have a fully co-ordinated team which we assembled based on our experience. The team included: Entuitive, JVM Consulting, Transsolar, Reinbold Engineers and the certifier from PHI in Germany among others. At every step – during design development, review of assemblies, costing reviews – the team always asked if we were meeting PHPP targets. We then worked with PCL on construction mock-ups that would meet the criteria of EnerPHit and serve as the standard should alternate details or products be suggested by the trades. Through this process we arrived at a tight ‘specs package’ such that the project met performance and was ultimately certified.

4. What did you learn from this first project about what worked and what could be improved?

As far as we know, this is the largest residential EnerPHit project in the world. The precedents for this type of work come from Europe but we realized that we need solutions that meet North American practices, products and trade familiarity. Our design made this its focus. The construction manager PCL was critical in the strength of their quality control regime, but some trades wondered early on if the PassiveHouse was overkill.  Yet as testing procedures became easier the consensus was these were key practices for use in future projects, Passive House or overwise.

There are two other observations. We would love to have trades more familiar with high-performance retrofits, and a supply chain that can provide more of the types of products for this type of work. But the evolution will happen. Since we went to tender three years ago, many more suitable products have become available.

5. Is the Ken Soble Tower transformation a practical template for the many similar towers in our building stock?

A resounding yes. The project gave us a lot of elbow room to try things because it was empty. We can apply the lessons learned to an occupied building. It was cheaper by half to renovate the Ken Soble Tower rather than tear it down and replace. The economics will improve further as the supply chain and trade skills improve. The incentive is an improved quality of life in revitalised buildings that are quiet, more comfortable, and more economic to operate in the long term. 

825 Pacific Street Artists Hub

New residential space provides public amenity and top performance

By Padraig McMorrow

With more than 2,000m² of affordable production spaces, independent studios, exhibition space and offices, 825 Pacific provides a vital injection of dedicated artist space into the City of Vancouver. The tallest Passive House building in Vancouver, 825 Pacific represents the Community Amenity Contribution made by the developer to the City of Vancouver, in exchange to permit the construction of rezoning an adjacent property for a high-rise residential tower. Because the City would take over the project, it was required to be constructed to the Passive House standard.

The seven-storey building stands next to the historic Leslie House, one of the oldest remaining single-family homes in Downtown Vancouver. To acknowledge the small scale and cultural importance of its neighbour, the ground floor of 825 Pacific, which will be a publicly accessible gallery, is set back to create a small entrance courtyard between the two buildings.

This is a core and shell project, with only the washroom and storage areas on each floor enclosed; the remainder awaiting subdivision by the tenants.The structure of the seven storey plus basement building comprises conventionally reinforced concrete walls, columns, floor slabs and roof slab. The stair cores located at the rear of the building provide the necessary lateral resistance.

Envelope

The slab on grade and basement walls are insulated with 125mm expanded polystyrene (XPS) which provides an effective thermal resistance of R-27. The roof, with 230mm of XPS laid on the slab, provides an effective thermal resistance of R-43 for the green roof. The ground floor concrete walls are insulated with 203mm mineral wool, which provides an effective thermal resistance of R-32.

The walls of the upper floors are steel stud with 152mm mineral wool batt insulation between the studs; with an additional 203mm of continuous semi rigid mineral wool insulation, supported by the thermally broken stainless steel brackets used to secure the metal cladding.

This wall assembly provides an effective thermal resistance of R-44. To mitigate thermal bridging, heavy gauge studs were used to reduce the number of brackets required; together with non-metallic through wall flashings.

Project Credits

  • Developer   Grosvenor Group
  • Owner  City of Vancouver
  • General Contractor  Ledcor Group
  • Architects  ACDF Architecture and Arcadis IBI Group
  • Building Envelope Consultant and Energy Modeller  Morrison Hershfield
  • Structural Engineer  Dialog
  • Mechanical and Electrical Engineer  Integral Group

Three shades of metal panels create a dynamic exterior pattern, and staggered windows from one floor to another contribute to the rhythm of the facade. The overall effect is that of a pixelated beacon to attract the public. EJOT® CROSSFIX® stainless steel thermal clip brackets attach the facade to the building structure to maintain thermal performance.

Padraig McMorrow Architect (Ireland) MRIAI, CPHC, Associate – Manager, Architecture Arcadis IBI Group Vancouver Office.

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PH-1 Lonsdale Avenue

Restaurant/office realized with design collaboration and prefabrication

By John Hemsworth

PH-1 is a small restaurant and office infill project in the Lower Lonsdale district of North Vancouver that employed virtual design and construction (VDC) and off-site prefabrication to meet challenges of access and constructability. VDC also made possible the installation of a prefabricated Passive House-compliant building envelope, including a zero-lot line wall adjacent to an existing building.

Originally an area of waterfront warehouses and marine service facilities, the neighbourhood has been transformed over time to a high density, mixed-use community centred on the Lonsdale Quay Market and Seabus Terminal. The consolidation of land required by the introduction of higher density zoning had left lots like this exceptionally difficult to develop.

As a family that had owned the property for three generations, the client was waiting for the right opportunity to do something special on the site. The idea of combining Passive House performance with modern mass timber construction was enthusiastically received, despite the many challenges and uncertainties it presented.

A waiver of the on-site parking requirement made it possible to design a three-storey building (with a ground floor restaurant and two storeys of offices above) that would achieve the full 2.53 FSR permitted by the zoning. The building made use of exemptions (applicable to the extra thick walls used in Passive House construction) to achieve a three-storey building, however, the 92% site coverage eliminated the possibility of an on-site staging area for materials and equipment, typically required for site construction.

Architecturally, the concept was to use the traditional warehouse vocabulary of an exposed heavy timber structure with brick cladding, but to interpret it in a contemporary way. This strategy has translated into an exposed glulam post and beam structure with cross laminated timber (CLT) floors, stair and elevator shafts.

The non-loadbearing brick cladding at the southeast corner of the building is ‘eroded’ away and replaced with large areas of glazing, providing restaurant patrons and office workers with an oblique view to the harbour.  The remainder of the south façade includes extensive glazing at ground level, with a staggered pattern of vertical windows, coordinated with glulam bracing elements, on the upper floors.

While the Code permitted the three exterior walls facing the streets and lane to be of combustible construction, it required the north wall abutting the adjacent property to be non-combustible. Such walls are typically built block by block in concrete masonry, a method incompatible with Passive House performance. A more sophisticated solution was clearly required, one in which the continuous exterior insulation and vapour barrier essential for Passive House performance could be installed without accessing the outer face of the wall in the field.

Using a VDC process involving the architect, structural engineer, building envelope consultant, contractor, and the mass wood fabricator and installer, a prefabricated and pre-insulated wall system was devised, then alternative detailing, assembly and installation strategies explored and optimized.

PROJECT CREDITS

  • Owner  Babco Equities Ltd.
  • Architect  Hemsworth Architecture
  • Structural Engineer  Equilibrium Consulting Inc.
  • Electrical/ Mechanical Engineer  MCW Consultants Ltd.
  • Civil Engineer  Vector Engineering Services Ltd.
  • Geotechnical  GVH Consulting Ltd.
  • Building Code Consultant  LMDG
  • Passive House consultant  Peel Passive House Consulting Ltd.
  • Landscape Architect  Prospect & Refuge
  • General Contractor  Naikoon Contracting Ltd.
  • Photos  Ema Peter

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Decarbonizing cement

By Jeff Ranson, Senior Associate, CaGBC

As we move towards 2050 targets for green building, embodied carbon is increasingly important to staying under the emissions budget and limiting global warming below 1.5 degrees Celsius. What is embodied carbon? It’s the product of the materials and construction methods we choose. This value is often stretched over the life of the building to reflect durability, the idea that a building built to last is likely better than one that will need constant repairs. However, the reality  is that those emissions are all fully released up front. Like net-present value in the financial world, a ton of carbon emissions today is worth more than a ton of carbon emissions tomorrow.

Of all the opportunities to reduce embodied carbon, the most significant is in concrete. Concrete is the most widely used building material, cutting across both buildings and infrastructure. And despite strong and promising market growth of alternative low-carbon materials including wood and biomaterials, concrete will continue to be a critical material for construction.

Potential as a climate solution

Reducing greenhouse gas emissions from concrete is a national priority. Natural Resources Canada and the Cement Association of Canada have committed to develop a decarbonization roadmap for the industry. For the designing construction industry, there are a few significant ways to reduce emissions today, and some very promising opportunities emerging.

In the immediate term, there are two opportunities to reduce emissions from concrete. The first is simply to minimize the amount of concrete projects use. This involves looking at how much concrete is required for the project and optimizing its use. This requires designers be conscious of how design choices such as massing impact material requirements. In many cases, designers are evaluating alternative low-carbon materials like mass timber to replace concrete, but nothing is as effective as just using less material.

One area in relation to embodied carbon that has been overlooked is the impact of land use planning. Infrastructure like roads, sewers, and transit require concrete.  There is no realistic substitution. Low-density suburban development oriented around the automobile results in huge amounts of embodied carbon, seldom considered in any municipal carbon strategies. CaGBC has been in discussions with researchers at the University of Toronto to better understand the relative carbon impacts of different development patterns, but at present there isn’t a well-established practice for evaluation. With more research we hope to understand the impact of embodied carbon from infrastructure and the importance what we build and where we build it.

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Doig River Cultural Centre

Community building brings superb energy performance to northern climate

By Peter Hildebrand 

The Doig River Cultural Centre in Rose Prairie, BC is among Canada’s most northerly PHI-certified projects and the first certified First Nations community building completed. The main level comprises 250m² of community-oriented space with an upper mezzanine for additional seating and a lower level comprising a daycare and an Elders lounge. The design, which allows for multiple uses within a single building, was intended to promote inter-generational interaction and fulfill the community’s desire for a safe and healthy space for all its members.

In such a small and remote community, a close network of buildings is crucial to establish a central gathering place and create a critical mass for community functions. The project’s site locates the Centre close to the existing community administration building to create a somewhat civic centre. This proximity also minimized the need for major infrastructure expansion.

Nestled into the slope in a grove of birch and aspen trees, the building complements its natural surroundings and offers a gesture of welcome at the entrance to the community. The slope also facilitates grade access to both levels, which eliminates the need for an elevator or wheelchair lift.

The choice of building form and orientation were critical, with a large south-facing roof and extensive glazing required to maximize winter solar heat gain and optimize PV panel exposure. This orientation also creates a dynamic display of light and shadow across the splayed walls as the melting snow constantly shifts and changes shape as it makes its way down the surface of the glass. The compact two-level plus mezzanine organization of the program minimizes the building’s footprint, reduces the surface-to-volume ratio, and lessens the environmental impact of the building on the site.

The structure is a hybrid of site-built and prefabricated components, thus increasing quality and precision. The primary structural system consists of glue-laminated arches with prefabricated panels between them that arrived on site with pre-installed insulation. An additional 300mm of insulation was added around the entire perimeter of the building, which was secured using wood strapping and 350mm screws.

The screws were oriented at opposing angles in a truss-like configuration to ensure vertical rigidity and prevent the insulation from sagging. Fastening the thick layer of insulation to the face of the sheathing required careful detailing and a new approach to the cladding system design. The exterior cladding materials comprise standing seam metal roof and wall cladding, and a composite shake product made from recycled plastic and wood fibres that comes with a 50-year warranty.

The sleek, straight-lined Prolok profile of the metal cladding, supplied by Westform, provides long-term durability in unlimited colour options.

PROJECT CREDITS

  • Architect  Iredale Architecture
  • Owner/Developer  Doig River First Nation
  • General Contractor  Erik Olofsson Construction Inc.
  • Landscape Architect  Urban Systems
  • Civil Engineer Urban Systems
  • Electrical Engineer  EDG Corporation
  • Mechanical Engineer  Rocky Point Engineering Ltd.
  • Structural engineer  Equilibrium Consulting Inc.
  • Passive House Consultant  RDH Building Science
  • Passive House Certifier  Edsco
  • Geotechnical Engineer  Golder Associates

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