Building materials are those things of which architecture is made. They are worth looking at in detail, especially in these transitional times where practices of extraction, manufacture, demolition and replacement have environmental consequences. Will this make a new kind of architecture? Many of the essays in this issue are optimistic. Yes.
ON SITE r e v i e w
Spring 2026
47
building materials
the small print about who we are:
On Site review is published by Field Notes Press, established in 1984, which promotes field work in matters architectural, cultural and spatial.
f ie ld
Randy Bye on the technical aspects of driving off-highway logging trucks on Vancouver Island FB group MATES IN TRUCKIN, June 15, 2024
notes
For any and all inquiries, please use the contact form at https://onsitereview.ca/contact-us
ISSN 1481-8280 copyright: On Site review . All rights reserved. The use of any part of this publication reproduced, transmitted in any form or by any means, electronic, mechanical, photocopied, recorded or otherwise stored in a retrieval system without the prior consent of the publisher is an infringement of Copyright Law Chapter C-30, RSC1988.
In an image search of logging trucks, many images are witness documentation of old growth stripping, the rest are about logging trucks as heroic vehicles, forestry as an essential industry.
Each individual essay and all the images therein are also the copyright of each author.
back issues: www.onsitereview.ca editor: Stephanie White design: Black Dog Running printer: Kallen Printing, Calgary Alberta
Log destined for export. Joel Wood, The Fraser Institute Log Export Policy for British Columbia , 2014. How this industry works. www.fraserinstitute.org
subscriptions: libraries: EBSCO On-Site review #3371594 at www.ebsco.com individual: www.onsitereview.ca/subscribe
nascent Building Materials There are a number of forest alliances, most decades old. One site, dating from 2010, said that if one has a piece of clear cedar it is undoubtedly from an old growth tree, harvested from an ancient forest on stolen land. One might start here: https://ancientforestalliance.org
on site review 48 building materials
the stuff buildings are made of
Architecture presents its material face to the world, its material structure to itself. In this issue we have challenges to this: materials can be ancient, convenient, inappropriate, problematic, surprising, apt. From traditional to innovative, from new to old, there are historical shifts along such trajectories that relate to technology, conflict, exploration, revision, identity, manufacturing and refinement capacities. Skill sets, scarcity of raw materials, or surplus materials — all these are unpredictable, and yet, somehow, architecture responds.
front and back cover who we are
Nascent building materials: lumber the fine print Introduction and contents
1,60 2 3
very hard materials
Sheila Ayearst Local Works Francesco Martire David Murray
Self-healing concrete Culture of construction Material vestiges: concrete formwork River rocks and field stones: prairie resources
4 8
10 14
building systems
Jim Moses Tegan Moore
Big Easy Redux: building strategies When the light thing becomes heavy: air and foam
20 26
wood
Rafael Gomez-Moriana Lisa Rapoport
Form follows material: CMT Wood shingles
28 32
material research
George Amabile Olive Lazarus Chad Connery and Selina Tran
Building materials: three poems Thatch Root logics
38 40 47
deep surfaces
Alisha Kapoor and Diana Guo
Soft matter
50
moving on
new call for articles , on site 49
Shorelines
51
Spring 2026
self-healing concrete
weathering research painting history
sheila ayearst
part 1
I am a visual artist who has been creating images of concrete since 1980. Here is the history of my obsession. Highway 401 in Ontario, Canada, runs 828 kms from the Quebec border in the east to Windsor, Ontario and the American border in the west. I have always loved super highways: the long curves; the perfect single point perspective of the lines; the landscape of the verges; the palette of grey, white, black, and a hit of yellow; the architectural power and mathematical simplicity of the overpasses, bridge supports and barriers. This human- made stone promised permanence for itself and security and efficiency for its users. But by 1989 the concrete of the 401 was already starting to crumble and then several women’s bodies were found dumped in the verge areas of the highway. My series of paintings, The 401 Towards London, 1990-1992 , were paintings of my photographs taken at the site of Jack Chambers’ iconic 1969 work, 401 Towards London , which was also the site of the 1990 abduction and murder of student, Lynda Shaw. They were painted the same size as Chambers’ work but in the format of my panoramic camera and were a response to both the beauty of the Modern but with awareness of how the Modern does not assure protection. This series was followed by another, Ruins and Monuments, 1997-2001 , which depicted fictional human touristing activities, in the manner of eighteenth and nineteenth century European Grand Tour paintings, at actual sites of construction or of tragedy along the 401.
The 401 Towards London: Overpass , 1990. Acrylic and oil on canvas, 183 x 244 cm.
The 401 Towards London: View , 1991. Acrylic and oil on canvas, 183 x 244 cm.
all images: Sheila Ayearst
Landscape with Ruin and Tourists , 1997. Acrylic and oil on canvas, 122 x 305 cm.
4 on site review 48 :: building materials
Between 1994 and 1996, I made paintings of the now-suburban Kitchener area around the Homer Watson Boulevard exit of the 401, and Homer Watson House Museum. My paintings were titled with titles from the list of Homer Watson’s missing works. In 1996, I also worked with now-suburban sites of works by Ozias Leduc in Mont Ste. Hilaire, Québec, and titled them with titles of missing Ozias Leduc paintings.
The Stone Road 36x51 1881 , 1994, Acrylic and oil on canvas, 71 x 147 cm
In the series, Supports and Barriers, 2001 - 2002 , (below) I commented on the beauty and frailty of these concrete structures.
Rushing Stream by Moonlight 18 ½ x 24 ½ 1905 . 1993, Acrylic and oil on canvas, 28” x 58”
Le pont de beton 1915 , 1996. Acrylic and oil on canvas, 152.5 x 366 cm
all images: Sheila Ayearst
Ash Barrier: 2002. Acrylic on canvas, 107 x 265 cm.
Weeping Support , 2002. Acrylic and oil on canvas, 229 x 122 cm
5
on site review 48 :: building materials
Concrete Portraits, 2010 - 2012 , depicted actual, small areas of the sidewalks that I walked over daily on my way to and from work.
Rain Concrete , 2011. Acrylic on canvas, 31 x 41 cm.
Beaconsfield Rd Concrete, 2011. Acrylic on canvas, 45.5 x 61 cm.
part 2
Although I had been making paintings of concrete off and on for 25 years, my finding, in 2018, of small pieces of Roman concrete, tumbling out of the 2300 year-old walls of Porticus Aemelia in Testaccio, was a revelation for me. They were of negligible value on the sidewalk, being crushed to their elements by the feet of pedestrians. I furtively bent and picked up several pieces feeling like I was stealing ancient gold. These little chunks of mortar were the subject of a group of works, Concrete Examples, 2019 - 2022 , in which I painted their portraits combined with copies of fresco details from the Palazzo Massimo in Rome and the villas of both Augustus and Livia on the Palatine.
all images: Sheila Ayearst
Concrete Example: Column , 2019. 91 x 147 cm. below : Concrete Example: Dado , 2021. 51 x 61 cm.
And then came the reporting of an enormous breakthrough in the understanding of the longevity of Roman concrete.
6 on site review 48 :: building materials
It has been an enduring mystery that in contrast to the brief lifespan of today’s OPC – Ordinary Portland Cement – the most common of construction materials, Roman mortars and concrete have endured earthquakes, weather and seawater for millenia. Scientists have long known from chemical analysis and from Roman writers such as Vitruvius, Pliny and Cato, that the ingredients of Republican and Imperial period concrete were lime from limestone or marble, pozzolanic (volcanic) materials such as ash, sand and tuff (a rock- like substance made of volcanic ash, tiny pieces of rock and pumice). But the exact mixing process remained unknown. The first step in the making of concrete is heating limestone in a kiln (calcinating) which forms quicklime. Quicklime must be hydrated with water. One way is to first add water to the quicklime before mixing everything together. This is called slaked lime. The other method is to add quicklime to all the other ingredients, including water, all at once. This is called hot mixing. Because slaked lime makes a more homogenous mix with smaller particles of lime, people have tended to accept this as the method employed by the Romans. But, in fact, large clasts (chunks) of lime are found in Roman concrete. This has been put down to incomplete or overburning in the kiln, carbonation before the preparation, incomplete dissolution during the setting, or plain improper mixing. In 2021 - 2022 , a group of scientists and researchers from MIT, DMAT Italy, IMM Switzerland, Wyss Institute and Harvard University, created a study to find out the exact ingredients and mixing method of Roman concrete. 1 They excavated mortar samples from Privernum, a town near Rome which was occupied from the second century BCE. These were analysed using SEM-EDS, a mapping technique which uses an electron microscope and X-ray Spectroscopy to produce detailed colour images which map the elements of the mortar sample. I found these images very beautiful - red (calcium from the limestone), blue (aluminum), green (silicon) and yellow (sulfur).
https://www.science.org/doi/10.1126/sciadv.add1602
Diagrams from Science Advances , vol 9, no.1 above: Optical micrographs showing the conspicuous bright white color of the lime clasts, which can easily be identified from large-area elemental mapping via SEM-EDS below: Lime clasts are morphologically distinct from other calcareous aggregate material (denoted by a yellow asterisk) and exhibit a distinctive particulate microstructure
https://www.science.org/doi/10.1126/sciadv.add1602
1 ‘Hot mixing: Mechanistic insights into the durability of ancient Roman Concrete’. Seymour, Linda M, and Janille Maragh, Paolo Sabatini, Michel di Tommaso, James C Weaver and Admir Masic. Science Advances , vol 9, no.1, Jan 2023.
7
on site review 48 :: building materials
Researchers found that cracks in the concrete were filled in with lime. They were sealed. Those clasts of lime in the concrete mix were not an accident or sloppy work - they were there to dissolve in rainwater and fill any developing cracks. Roman concrete was self- healing!
The term self-healing is so humane, so kind. It speaks to our psychology and fear of ecocide more than to building engineering. It is a term very much in the forefront of humanity’s twenty-first century zeitgeist. I started work on a new series, Self Healing Concrete , in 2023. For the viewer, the perception of the imagery in these paintings is altered by the reading of their titles. *
above: Self Healing: Failure , 2025, 46 x 23 cm. right: Self Healing: Colour , 2025. 86 x 122 cm. below: Self Healing: Black and White , 2024. 81 x 122 cm.
all images: Sheila Ayearst
SHEILA AYEARST, born in Ottawa, BFA from York University, lives and works in Toronto. She has exhibited throughout Canada and is represented in museum, corporate and private collections. https://sheilaayearst.com
8 on site review 48 :: building materials
Culture of construction two archives /,one practice
bui lding research materials records
Master builders, with an all-encompassing knowledge of construction, gained through a life spent in apprenticeship and practice, were the original architects. Etymologically, architect derives from the Greek arkhi : chief + tekton : craftsman; much removed from our contemporary understanding of the role of the architect designer as the mind, but not the muscle, behind every building. Even today, the dwellings and residential landscapes of the global majority are designed through building, by tradespeople, competent amateurs and the collective efforts of communities. Designs evolve and unfold within an iterative culture of construction, and adapt to the limitations of their geographical, ecological, social and economic context, long after people take up residence. By necessity many of these practices have a low impact, even a regenerative effect, on their surrounding natural environment. The rise of industrial production of the built environment across the world is seeing the demise of such adaptable, light-touch practices at a time when we need them most. Conventional modern construction has developed in response to an ever-increasing demand for predictable efficiency and ‘quality’. As the ultimate goal of property development, the elimination of financial risk for investors is sought through a homogeneous culture of standardised procedures, conservative over- specification of materials and just-in-time production. Building materials and components are created at scale in digitised and
mechanised systems, with little regard for the environmental and social consequences of their production and transport via global supply chains. Waste is an inevitable by-product of such a hurried and linear industry, where there is no time for the inevitable, unpredictable delays and mistakes that arise when operating in the context of a living planet. The human construction worker is an inefficient instrument of the system. An alternative to this indifferent, growth- oriented model of construction where profit is centralised, might aim to reclaim the process of building for the purposes of a more ecologically sustainable and socially just pluriverse of global communities. It could consider the local landscape of any site by designing and working with materials procured, transformed and applied with the least movement, processing, additives and layers. Through every material and operational choice an opportunity to create positive ecological impact and to improve social and personal outcomes for all those involved can be seized. As the central autonomous agent in this process the builder is in a position of both giving and receiving those benefits but is also pivotal as the keeper and conveyor of its culture and methods. Construction that is flexible and responsive in nature, based on observation and practical experience requires a different approach to learning and translation of knowledge, and therefore archiving. It is instructive to think about what archives of building might already exist. *
Arch-ive investigates the books that have been influential to leading urban practitioners. It aims to showcase architects’ relationship with books and the way in which they utilise, interrogate and display architectural resources.
arch-ive.xyz
Building on the Built is a platform which aims to promote the topic of architectural work connected with existing structures and, more specifically, to look at work that might challenge the way in which work on existing structures is approached today. Building on the Built focusses on work that celebrates an alternative to pure architecture, work that is evolving, mongrel and collaborative with time. www.buildingonthe- built.org Local Works Studio , established in 2017 is a partnership between a landscape architect and a building craftsman. We are makers and thinkers who design places with people. We are optimistic, collaborative, creative and inquiring. We draw on a wide network of trusted collaborators and specialist consultants to help deliver projects.
This is an excerpt from a longer interview recorded by Loretta Bosence, of Local Works Studio. It is published in Building on the Built, describing Arch- ive Editions, an irregular publication that focusses on the books that have influenced architectural disigners, that they refer to, and use in practice. The full interview can be found here: www. buildingonthebuilt. org/archive- archive-edition-3- excerpt
localworksstudio.com
Local Works
Brick prototype by Local Works Studio
9
on site review 48 :: building materials
Material Vestiges FormWork / the Forgotten
concrete construction surface silent partners
Francesco Martire
It is paradoxical really… the permanence of concrete requires temporary assistance of a secondary material to shape its tangible presence in architecture and landscape architecture. So many of its characteristics are determined by a material no longer present, formwork. Despite its temporality, formwork leaves permanent impressions. Integral form, texture, rhythms, colouring are all the result of an ephemeral mould assembled and then removed. Formwork traces the process of pouring concrete as a building material. Its visual and tactile surface qualities rely upon a fleeting relationship with something else for it to speak its intended language.
Other materials used in architecture and landscape use input energy to form them: steel ingots are shaped by extreme temperatures and a series of rollers to make a beam or channel. Large saws transform felled logs into dimensional lumber. Input is typically super-sized pieces of equipment in massive manufacturing plants, or a plethora of tools used over and over again in workshops or on site. Concrete is special. It is transported to site wet and formless, requiring an entire structure assembled in advance of its delivery with which to interact. Concrete, mould, curing time and discarding the mould describes the construction process — a brief moment of overlap with long lasting results.
Whether orthogonal and rectilinear or sinuous and sculpted, formwork is concrete’s inverse shape. The Teshima Art Museum , Kagawa Prefecture, Japan, designed in 2010 by Ryue Nishizawa, a co-founder of SANAA, is a beautiful low- slung dome echoing its contextual topography. Two oculi let both light and weather into its interior. The project’s singular
material is white concrete which used earth as formwork. A grading plan for compacted fill built a hill as formwork, upon which concrete was poured. The hill was then excavated through the oculi — a poetic topographic and landscape interpretation of formwork as something designed not to last but which is critically important.
Iwan Baan arquitecturaviva.com
Ryue Nishizawa, Teshima Art Museum , 2013. Teshima, Kagawa Prefecture, Japan
10 on site review 48 :: building materials
The cadence of the surface of concrete is defined by its form work. Sheet material gives a slower cadence; boards a more rapid one. The small ridges of cement that seep out between formwork’s edges give an otherwise seamless surface a unit of measure. The walls of Tadao Ando’s Church of Light just outside Osaka, show traces of the 1220mm x 2440mm phenolic sheets used for the formwork. The sheets were laid horizontally in a stacked bond pattern, each sheet dotted precisely with a series of evenly spaced tie rod ends.
A scale-less material (the the concrete) was given a a recognisable unit scale produced by its construction technique. The impressions left by the carefully arranged formwork sheets are not simply a tracing of the forms but indicate the level of care and craft invested by its architect forvever embedded in the project’s thick concrete walls. These impressions remain as trace artifacts, a ghost of itself, physically removed but made present as a condition of the construction process.
Hiromitsu Morimoto metalocus.es
Tadao Ando, Church of the Light , the main chapel of the Ibaraki Kasugaoka Church, 1989. Ibaraki, Osaka Prefecture, Japan
11
on site review 48 :: building materials
Rasmus Hjortshøj-Coast, divisare.com
Peter Zumthor, Bruder Klaus Kapelle , 2007. Mechernich-Wachendorf, Germany
it, leaving behind a richly textured surface coated in a black char — a rich texture of charcoal-to-sooty tones integral to the process of making. There is an honesty to the material surfaces that do not rely on further applications of material to create additional effects. It is an efficient, integrated and thoughtful strategy employed to elevate a material quality. Deep blacks in the shadowy ridges of the corrugated concrete sit in stark contrast to the controlled slivers of light permitted to enter — a mysterious and ephemeral surface with extreme tactility that demands touch.
Formwork textures, dimensions and imperfections create an idiosyncratic choreography typifying concrete’s shape and surface qualities. Even the way the formwork is removed, after the pour and the concrete is set, can add to idiosyncrasies registered on concrete’s finished surface. Peter Zumthor’s Bruder Klaus Field Chapel in Mechernich is a compelling example of the extraordinarily beautiful results made possible by both inventive formwork and similarly inventive removal. Dowels, lining one side of the formwork, corrugate the interior surfaces. The dowel-lined formwork is removed by burning
12 on site review 48 :: building materials
Trevor Patt archeyes.com
Carlo Scarpa, Brion-Vega Tomb , 1968-1978. San Vito d’Altivole, Treviso, Italy
In the work of Carlo Scarpa at the Brion Vega Cemetery, the unit is reduced to the smaller scale of timber boards laid primarily horizontally. The scale of the boards works with the dimensions of steps in the wall establishing a proportional syncopation with various components within the project. On the exterior surfaces of the concrete the seams of the board formwork have influenced the patina on the concrete’s surface: the small ridges of cement at each board seam create miniature ledges where storm water collects and stains the concrete surface with unique subtleties. The transference of wood’s grain and knots from the boards to the concrete’s surface are another trace of the material that helped shape it.
Formwork is a ghost, a vestige of a former self that leaves a trace — felt, without being present. Concrete, uniquely, needs temporary material assistance to create its own long-lasting reality. While the relationship between concrete and its formwork is but a fleeting moment, formwork’s permanence is felt in concrete’s shape, seams, textures and patinas, the tangible tracings of material in absentia . Entangled, ephemeral yet permanent, therein lies the paradox of formwork. *
FRANCESCO MARTIRE is an architect, landscape architect and co-founder of large [medium] design office , a multi- disciplinary practice based in Toronto. He is an associate professor, teaching stream at the Daniels Faculty of Architecture, Landscape and Design, University of Toronto. https://largemdo.com
13
on site review 48 :: building materials
river rock and fieldstone boulders on the prairies
stone masons restoration ski l l
davd murray
stories from an architectural practice It is common to see stone piles along Alberta’s country roads. They are the result of glaciation, deposited in the soil as the last ice age, the Wisconsin Glaciation, retreated from the western prairies approximately 12,000 years ago. For prairie farmers they have always been a nuisance for ploughing and their removal an annual chore because the winter frosts tend to push underground field stones to the surface. Likewise, when drainage rivers were formed by the melting glaciers, some boulders were left on the land and some made their way into the river beds, accumulating irregularly as the the spiritual life of prairie field stones For millennia before European settlement, western prairie boulders were used by Indigenous Peoples to mark the spiritual significance of the landscape with medicine wheels. The Rumsey Cairn, right, or ‘Indian Stone Pile’, near Rumsey in central Alberta was first recorded in 1802 by Hudson’s Bay Company explorer Peter Fidler from one of the drawings by Ki oo cus (or Little Bear), of the places important to the Blackfoot. The age of this medicine wheel is uncertain although it may be protohistoric. 1 An earlier historic Indigenous site, near Bassano Alberta, the Majorville medicine wheel ( Iniskim Umaapi ) provides a record of place where Blackfoot ritual activity links the present with the past, and the past to the future. Iniskim (buffalo calling stones) are a central element of Blackfoot ceremonial activity. They are present in exposed bedrock formations underneath the medicine wheel and have been recovered from archaeological excavations at the central cairn. Offerings of sweetgrass, sage, willow, cloth, tobacco, prayer and song symbolically maintain the link of contemporary Indigenous Peoples with their ancestors, and continue to be left at the cairn. Archaeological studies indicate this site has been continuously used for the last 4,500 years, making this one of the oldest religious monuments in the world. Artefacts were deposited in the cairn in an accretional fashion, like layers in an onion, with the oldest materials on the inside and the more recent materials towards the outside. Excavation demonstrates that this sequence of use mirrors other such sites in the area, an indication that the medicine wheel was an element of in-place Plains spiritual culture for millennia. 1
glaciers advanced and retreated, creating the rapids found in the great prairie rivers. I know this from my own experience having a country cabin near the Pembina River that flows from the mountains west of Edmonton and empties into the Athabasca River. The river rocks, driven from the Rocky Mountains by advancing glaciers, are normally hidden in deep river water and not as easily gathered as the stones that appear in quantity in farmer’s fields. 1 But for builders both fieldstones and river boulders present an opportunity.
from the top: drawing of the Rumsey Cairn : the cairn at the centre
of the Majorville Medicine Wheel : aerial view of the whole Majorville Medicine Wheel. What might be
considered vandalism in the initials and dates seen from the air, is a possible continuation of medicine wheel use.
Heinz Pyszczyk
1 Indigenous Peoples did not use river boulders for sweat lodges because the rocks were saturated and would explode in a fire. 2 Brumley, John H, ‘Medicine Wheels on the Northern Plains: A Summary and Appraisal’. Archaeological Survey of Alberta, Manuscript Series No. 12 , 1988
Alberta Culture and Community Spirit, Historic Resources Management
14 on site review 48 :: building materials
field stone as building material My first encounter with field stone as a building material was at the site of the historic Lac La Biche Oblate Mission, established in 1853, 212 km north of Edmonton. We always knew that the original late nineteenth century building foundations were made from uncut field stones that would have been collected from the Mission’s fields adjacent to their location beside Lac La Biche. In 2012, I prepared a conservation plan for the entire Lac la Biche Mission site for a Parks Canada-funded conservation study. In the report, I noted that the church’s shallow stone foundations, rebuilt after a 1921 tornado, were severely out of alignment and had deteriorated after years of winter frost heave. Lac La Biche Mission is a designated and protected Provincial and National Historic Site. In consultation with a provincial heritage advisor, it was determined that the most appropriate form of conservation would be to completely restore the uncut stone foundation in situ , using the original stones and lime-based mortar materials, with a small amount of cement added to the lime mortar mix to increase durability. 3 As much as field and river boulders formed the earliest building foundations in the 1800s, by the 1900s the new settlers were looking for a more sophisticated use of field stone as a building material. The first Lac La Biche Mission Convent building, believed to have been constructed substantially from stone as determined from the rock piles at the site, had failed by the 1890s probably due to poor, or unstable, soil conditions. It was evident that the use of stone as a building material would require a solid concrete foundation to become a stable structural building component.
Lac La Biche Mission Archives
James Dow
from the top: the nineteenth century Lac La Biche Mission, founded by the Oblates of Mary Immaculate in 1855. Lac La Biche Church prior to restoration Testing the depth of the foundation wall and the soil it rests upon. The Lac La Biche Church foundation, before and after restoration
3 The repair and restoration work were completed in 2014 with the invaluable historic masonry expertise provided by Scorpio Masonry, Edmonton.
field images: David Murray
15
on site review 48 :: building materials
restoring field stone in Banff, Alberta In 2001, I was engaged to prepare a conservation plan for the restoration and repair of the historic facade of the Harmon Building, known as Harmony Lane, at 111 Banff Avenue in Banff, Alberta. This is a remarkable building completed in 1920 by the famous mountain photographer, promoter and entrepreneur Byron Harmon. Harmon was an ardent advocate for a rustic ‘National Park Style’ architecture for Banff; the use of uncut field stones for his building façade is an important factor in the design evolution of this mountain town. Both river stones and field stones would have been readily available to Banff’s masons; in this case natural stone was both aesthetic and structural.
Byron Harmon died in 1942; by the 1960s his son Don decided that the building needed updating. The original, elegantly tapered stone columns were covered and straightened with cut and shaped fieldstone, a more ‘modern’ look. When Byron Harmon’s granddaughter Carole Harmon and her children Sebastian and Julia Hutchings, became the owners after Don Harmon died in 1997, Carole’s vision was to have this building protected as a significant historic resource. It was recognised in 2001 as the first municipal historic resource in Banff under the Alberta Historical Resources Act. The building façade was restored to its earliest configuration, uncovering the original tapered fieldstone columns along Banff Avenue.
Whyte Museum and Archives, Banff, Alberta. R A Millar Collection
above: the street elevation of the Harmon Building, and above left: a section through the wing. These working drawings were prepared for Byron Harmon by Calgary CPR architect, R A Millar. The original 1914 building, with the 5 structural field stone columns along the facade, was constructed by Byron Harmon as a movie theatre and designed by Chicago architect Harvey Wright. When the theatre burned down in January 1917, right , the structural stone columns across the front were the only part left standing. By July 1917, part of Millar’s design for the new building had been built and occupied; the rest of the building was completed by 1920 below: Harmon’s in 1914, before it burned down. below right: Banff Avenue and the Harmon Building after restoration in 2004
courtesy of Shannon Angell
Carole Harmon
16 on site review 48 :: building materials
conserving field stone buildings A 1920s example of split-face fieldstone as a building material is the Keillor Farmstead. An early Edmonton doctor and a captain in World War I, Frederick Anson Keillor returned to Edmonton in 1918 and private practice as a doctor and surgeon, purchasing from the City a 61 acre parcel of farmland in the North Saskatchewan River valley for a working farm. By 1920 he had constructed a large log cabin, and in 1929 built a separate stone house and a stone summer kitchen attached to the cabin. For Dr. Keillor, an advocate of the health benefits of outdoor activities, the use of log and stone was purposely rustic, a look used for national and provincial parks throughout Canada. The log cabin had already been restored in 2017; in 202 I I was engaged as the conservation architect for the restoration of the Stone House and Summer Kitchen, both significantly deteriorated. Work started in 2022. The project was primarily to restore a fine example of fieldstone masonry; my goal, in association with Spectacle Architecture, was to complete the restoration with the expertise it would take to accomplish this. In both buildings the foundations had failed causing severe deterioration of the solid stone walls. The foundations of both needed to be replaced before the stone walls could be repaired. The Stone House was lifted in situ and a new concrete basement constructed underneath. Unlike the Stone House, the Summer Kitchen was in worse shape and had to be completely dismantled in order to lay a new supporting concrete slab on grade. To faithfully reconstruct and restore the fieldstone walls of these buildings, they were carefully documented by both the architects and eventually the stonemasons. These documentation photos, along with careful sorting and storage of the stones, allowed the masons to accurately replicate the locations and orientation of the original stones. The Dr Keillor Farmstead Stone House and Summer Kitchen were designated as a municipal historic resource by the City of Edmonton in October 2022.
Lynn Leenheer
The farmstead in the North Saskatchewan River parkland circa 1950.
The Keillor family in front of the summer kitchen attached to the cabin. Whitemud Equine Learning Centre Association, Edmonton
David Murray
David Murray
The scope of this project is seen in the completed restoration in 2024. The Stone House is on the left, the Summer Kitchen, attached to the log cabin, seen behind it, is on the right.
The failure of of the Summer Kitchen 1929 foundation meant that the stone walls had started to collapse. Complete re-building was necessary.
17
on site review 48 :: building materials
A page from Scorpio’s manual on Masonry Restoration showing their traditional stonework tools.
The kitchen was documented in photos and drawings and the roof was removed intact before the stone walls were dismantled. All materials were saved and stored for reconstruction. The roof was repaired and then re-attached when the walls were complete.
all images this page: David Murray above: large photographs of the original walls were the guide for the exact re-laying of the original field stonesl. The new framing replaces the original interior partitions and the lining of the stone walls. middle right: all the log ends for both the Stone House and the Summer Kitchen were replaced and fitted into the original log rafters. right: in the completed reconstruction of the Summer Kitchen a new at-grade concrete foundation was constructed, and replacement interior partitions were built before the stone walls were rebuilt. The weathered log ends were all replaced and finally the repaired original roof was re-attached.
18 on site review 48 :: building materials
Photographic documentation of the stonework was important to the restoration. The left side of this photo of the Stone House shows the deteriorated stonework (compared to the right hand side of this wall, due to the failing foundation.
all images David Murray
Skilled Scorpio Masonry stonemasons rebuild the walls exactly as the documentation before de-construction indicates.
the conservation of expertise There is almost no record of who the first Alberta masons were who worked in stone. It is an ancient skill and many masons brought their expertise to Alberta as immigrants. The fine restoration work that was accomplished at Lac La Biche and later at the Keillor farmstead was provided by Scorpio Masonry from Edmonton. Over the years, I have worked with Scorpio’s specialist masons who have the skills to work with the cutting , splitting and setting of stone. On many historic projects I have counted on the skills of their tradesmen. Mike Ambrosic, founder of Scorpio Masonry, was actually trained as a tool and dye maker in Yugoslavia, came to Canada in 1961, then went through an apprenticeship program in Moose Jaw working for Pockar Brothers Masonry. He then went on to be the site foreman on numerous Alberta masonry projects before starting Scorpio Masonry. Chris Ambosic, Mike’s son writes: Fieldstone masonry is very much an artisan skill that is slipping away. The last new field stone project we did was in Saskatchewan in 2006, the University of Saskatchewan Kinesiology Building. We harvested large dolomite boulders from farmers around Saskatoon, sent them to Edmonton for cutting and splitting, all by blades and hydraulic splitting. 2
A new, deeper, more functional basement was constructed under the Stone House. The process is that the building was set on girders and lifted in situ , and the basement build underneath. The deteriorated stone work was then repaired.
conserving historic building materials The heritage value of the Keillor buildings is associated with both the intangible history of Dr. Keillor and the tangible building materials, including the windows, doors and log- supported roof, all of which were fully restored. The Keillor fieldstone construction stands out as the most prominent of the building materials and was also the most challenging to restore convincingly. Historic stone construction in Alberta is relatively rare. The Keillor buildings remain some of the best examples of stone construction in Alberta. *
DAVID MURRAY is an architect in Edmonton specialising in the conservation of historic buildings and their materials, in both Alberta and the Northwest Territories. Each project has benefited from the expertise of masons and carpenters, as well as the support of enlightened municipal and provincial heritage programs.
2 In northeastern Alberta and east-central Saskatchewan, dolomite outcrops are found in shield-marginal lowlands.
19
on site review 48 :: building materials
Big Easy Redux building strategies
carbon mass timber alternatives crises
james moses
In 2020, the journal Nature reported that, driven by accelerated urbanisation, consumption and the abiding tabula rasa approach of modern development, man-made mass had surpassed biomass for the first time in human history. The weight of plastic alone was greater than that of all land and marine animals combined. Since the beginning of the twentieth century, anthropogenic mass has doubled every 20 years. Today, buildings account for about 40% of global greenhouse gas emissions; building materials are about 11% of that. In 2017, the planet had 2.5 trillion square feet of constructed space, with projections doubling that amount by 2060: the equivalent of building Paris every five days. The amount of carbon we can emit over the next 27 years under the Paris Agreement is 420 gigatons, and we are currently spending 53 gigatons per year. We will hit 1325 GT by 2050. To reduce this, we must reduce carbon that is emitted now . Our interconnected ecological, economic, geopolitical, and social crises are based on decisions made years ago. How, if our understanding of reality had been more sophisticated and there had been the political will, might we have recalibrated. 1
a case study: design of the Merryl and Sam Israel Environmental Science Building This project began in 1997 with Wilson Architects in Boston. The firm was new, founded in 1995 by a number of architects from Payette Associates, which had been awarded the Environmental Science Building commission and which generously allowed the fledgling firm to continue with it as a means to becoming established in its own right. At the time, it was a given that science buildings were ‘energy hogs’ in their operational consumption, driven primarily by the demands of lab exhaust ventilation and electricity required for operating equipment. Energy was relatively inexpensive and energy efficiency was not yet a salient part of design conversations. Lessons that might have been drawn from the era of the oil embargos of the 1970s were distant memories. There was little or no understanding of what Lloyd Alter has since coined ‘upfront carbon’: carbon emitted during material extraction, manufacturing, transportation to the construction site and assembly. 2 Discussions about climate change were just starting. The United States Green Building Council, founded in 1993, was in its infancy and its LEED rating system did not yet exist. The Kyoto Protocol was signed late in 1997. Hurricane Katrina devastated New Orleans in 2005.
The Merryl and Sam Israel Environmental Science Building , Tulane University, New Orleans, Louiiana. 1997 Wilson Architects, Boston, Massachusetts
South elevation
Wilson Architects
2 Alter, Lloyd. ‘Lloyd Alter On Upfront Emissions’. Green Building Advisor, 2023. https://www.greenbuildingadvisor.com/ article/lloyd-alter-on-upfront-carbon-emissions. Accessed 1/26/2026
1 Given NASA climatologist James Hansen’s warning to the US Congress in 1988, were the 1990s the moment to take global action to dramatically reduce emissions?
20 on site review 48 :: building materials
In the years since the Environmental Science Building was completed, design and construction teams have become more aware of operational emissions, re-learning passive strategies around solar orientation, appropriate use of natural ventilation and daylighting. Building envelope assembly design has become a critical piece of the efficiency puzzle, particularly for controlling air leakage. Engineers have put more effort into right-sizing energy efficient systems and including onsite renewable energy sources. Zero net operational emissions have been possible for some time. Offsetting with renewables to achieve zero net emissions, however, is not the same as zero emissions — a critical distinction as some greenhouse gas emissions linger in the atmosphere for up to a thousand years. Despite the absence of an explicit sustainability agenda for the building, the design team incorporated passive strategies to the extent practical for a building of instructional laboratories, associated support for introductory and organic chemistry courses, research laboratories, support for environmental science and engineering, faculty offices, conference rooms and space for computing. Gross square footage of the building is roughly 50,000 divided into four stories. Passive strategies optimised solar orientation – creating a narrow courtyard, in shade much of the day, between the new and an existing science building, Stern Hall (top right). Shading devices extend the roof eave on the south elevation and glazing is set back in the thickness of the wall (right) . A narrow floorplate and tall windows allow daylight deep into the section (below). On the north side of the building the instructional labs on the ground and fourth floors access is directly from outside, reducing the overall cooling load . Chemistry and biology laboratories, because of stringent mechanical ventilation requirements, do not have operable windows, but offices and conference rooms can, and are equipped with ceiling fans.
top: Courtyard between the north side of the Environmental Science Building on the right and the existing Stern Science building on the left. above: The south side of the Environmental Science Building has sun ameliorating shading devices and deeply set windows. left: Instructional Lab: Introductory Chemistry. The fairly narrow floorplate allows daylight deep into the section.
all images Wilson Architects
21
on site review 48 :: building materials
As the power grid becomes cleaner and buildings more energy efficient, operational emissions decrease, becoming a negligible proportion of a building’s life cycle emissions. At the same time, upfront and end-of-life (demolition and disposal) emissions grow as a share of total life cycle emissions and rightfully draw increased scrutiny. Even as the grid becomes cleaner, building construction occurs downstream of extractive and industrial processes and transportation. Until those sectors are carbon free, buildings will not be. I want to focus on the two building systems that contain 50- 75% of a building’s upfront carbon: the structure and envelope, and reconsider decisions made in the late 1990s without concern for those emissions. Properly designed and constructed, these systems should also be the longest lasting among the so-called shearing layers of a building - an idea developed by British architect Frank Duffy. 3
Carbon Leadership Forum, the Time Value of Carbon, Foundations, structure and exterior envelope are responsible for the majority of a building’s upfront carbon emissions.
How might the architectural drivers of the decisions made in 1997 be addressed in the same building today?
The Environmental Science Building was designed for a long life. If the idea of the hundred-year building was not explicitly discussed, the Vitruvian triad was certainly in the minds of the design team. Laboratory design lends itself to a repetitive structural module, generous floor-to-floor heights, and optimised daylighting. The building re-configures one end of an historic quadrangle (right) , masking an existing, relatively mute 1970s era pre-cast concrete clad science building. It was believed that durability, usefulness, and beauty would lead to a long-lived building.
Shearing layers of change: because of different rates of change of the components, a building is always tearing itself apart.
The Environmental Science Building (orange) re-configures Tulane’s Academic Quad, while creating a narrow, shaded courtyard running east to west between itself and the existing Stern Hall
3 Brand, Stewart. How Buildings Learn . Viking, 1994, pp.12-13.
22 on site review 48 :: building materials
Reinforced concrete has among the highest upfront carbon emissions of all building materials primarily from production of portland cement and steel for rebar. There are, of course, ways to reduce these emissions such as substituting fly ash for cement and fiberglass for steel rebar. While it is not as emissions dense as, say, aluminum, its weight when used as a building element makes it a significant contributor of emissions. Designed today, given the original criteria and a new concern for reducing upfront carbon, cross-laminated timber construction combined with glulam columns and beams, would be a serious consideration. This system, which is significantly lighter than concrete, would pair well with the helical piles proposed as the substitute for concrete piles. This would offer additional benefits to the well-being of the building’s occupants through enhanced biophilic connections to the natural world, supporting the high priority given to daylighting and views. Other benefits of mass timber construction include improved indoor air quality, enhanced sound absorption, and thermal stability. And perhaps most importantly, mass timber sequesters carbon in its cells, rather than emitting it to the atmosphere. There are other issues to consider in substituting cross- laminated timber or CLT construction for concrete, such as fire resistance and vibration. There are now UL assemblies and details that address the fire resistance issues, so this concern can be overcome by careful detailing and construction methods. Concerns about vibration arise particularly in science buildings with precision instrumentation in use. There are two possible approaches: dampening or stiffening. Dampening involves placing a lightweight concrete topping on the CLT floor deck. Stiffening involves adding beams to reduce the span of the deck. The potential for deconstruction and recycling, rather than disposal, is enhanced by using dry construction processes such as bolting. Deconstruction and recycling reduces end-of-life emissions and keeps waste out of landfills.
Because New Orleans is low-lying, most of it below sea level, the building has no basement. The main mechanical and electrical equipment are in a penthouse, so while not explicitly done for reasons of sustainability, a reduction in the amount of concrete used was built-in by virtue of local topography. This was offset by the poor bearing capacity of the soils, necessitating deep piles and a structural (spanning) ground floor slab, rather than a conventional slab on grade. Considered today, there is likely little that could be done about the structural ground floor slab. Removing soil and replacing it with structural fill would have been considered at the time of design and judged too costly compared with a structural slab. It is likely, however, that using lighter weight steel helical piles would reduce the upfront emissions. This would probably only be feasible if there were a lighter superstructure. The superstructure of the Environmental Science Building is in situ concrete, and was selected primarily for its potential 4 aesthetic quality. It is exposed and there was particular architectural interest in the floor slab system, formed using a modular pan system to create a primary (beams) and secondary (joists) scale. This decision was also based on establishing a kinship with the existing Stern Hall, which has a similar structural system. Lastly, there was a functional rationale for the exposed structure: it is not unusual to expose the mechanical, plumbing, and electrical systems in a laboratory environment, as there is often the need to access those systems to maintain or add to them. Exposing them eases those processes and makes the building more adaptable over time.
TSW Design
Global warming potentials of common building materials
4 ‘Potential’ because exposed site-cast concrete carries with it a certain amount of risk, despite a design and construction team’s best efforts. Formwork can be deformed once the concrete is placed and honeycombing on the surface can be caused by poorly vibrated concrete, just two possible undesirable outcomes. A stringent specification is no guarantee, particularly in a construction market that lacks experience with architectural concrete. One must be prepared to accept the unexpected.
23
on site review 48 :: building materials
Page 1 Page 2 Page 3 Page 4 Page 5 Page 6 Page 7 Page 8 Page 9 Page 10 Page 11 Page 12 Page 13 Page 14 Page 15 Page 16 Page 17 Page 18 Page 19 Page 20 Page 21 Page 22 Page 23 Page 24 Page 25 Page 26 Page 27 Page 28 Page 29 Page 30 Page 31 Page 32 Page 33 Page 34 Page 35 Page 36 Page 37 Page 38 Page 39 Page 40 Page 41 Page 42 Page 43 Page 44 Page 45 Page 46 Page 47 Page 48 Page 49 Page 50 Page 51 Page 52 Page 53 Page 54 Page 55 Page 56 Page 57 Page 58 Page 59 Page 60Made with FlippingBook interactive PDF creator