Chapter 6: Design and Construction Strategies

Introduction

Conventional construction practice is focused on efficiency: the typical process begins with clearing the site – ie with the removal of “organics” – trees and any vegetation present within the footprint and environs of the building, and scraping off of any topsoil if present. These and similar practices may be acceptable in the urban context where coverage of large percentages of buildable area  – often up to 100% – are permitted but care must be taken to ensure that these practices are controlled on large or rural sites.

This practice also obliterates any indigenous species that inhabited the site and has resulted in much environmental degradation.

Conventionally designed buildings assume that any needed services are available – usually at the property line – and can be brought to and taken away from the site as needed. In the urban environment this generally includes electricity, domestic water, and wastewater drainage, and can also include natural gas and district heat. Rural sites may have few if any of these services readily available and the scope of design may include a wide range of areas: minimizing energy consumption, achieving water independence, management of all wastes on site and renewable energy generation

This chapter explores the range of tools and techniques components and systems available to the architectural designer to respond and engage effectively to the existing as well as future site conditions.

Understanding the site and its sensitivities and opportunities is key in the development of building & site development designs aimed at reducing the overall environmental footprint of the project. which includes both available to the architectural designer to develop designs that respond effectively to and integrate or align with the existing site and conditions.

Prior to the introduction of the electrical and mechanical systems we have taken for granted in buildings in the last century, it was necessary to design buildings in a manner to take passive advantage of a site’s ambient conditions in order to access the daylight and air needed to make interior spaces inhabitable and useable.

The advent of modern active building systems revolutionized the way buildings could be inhabited – electrical and mechanical systems and their ability to provide a well-lit temperature controlled heated ventilated indoor environment has enabled the design of much larger buildings and functions not possible without the services that these systems can provide. and have. Artificial lighting, fan powered distribution of fresh air and heating /air conditioning systems have enabled the  de-coupling of the design of buildings from the necessity of meeting the climatic constraints of the site and enabled the design of much larger buildings than had been possible without these systems.

Aligning the design of building systems where possible with the site’s ecosystem services is an important strategy to pursue to reduce a building’s environmental footprint.

The combination of these mechanical and electrical systems with the easy availability and affordability of energy – has resulted in the loss of much of the passive design knowledge and strategies that had been the norm for many centuries and across many cultures before these engineered systems became widely available. The abundance of cheap energy has also meant that there has been little financial incentive to design more energy efficient buildings. For many building operators, it still remains less costly to waste energy than to conserve it.

As the impacts from climate change have become more evident, the performance of buildings has come under intense scrutiny with buildings identified as one of society’s major Green House Gas (GHG) emitters and that that GHG emissions have been a major contributor to climate change. This has led to the realization of the importance of accessing site based resources to help reduce a building’s environmental  footprint, through offsetting the need to import these services from off-site.

Understanding the Site:  Predesign Site Analysis:

Predesign Site Analysis:

Understanding the essence of a place is one of the key activities of the architect, as a frame of reference for the future project and a source of inspiration. Simply put – Site analysis – for the designer – is the investigation and research needed to familiarize one with the site for the design project in question.

The site analysis and information gathering stage is a crucially important project specific activity.  It is at this stage that many important decisions are taken. If the information at hand is incorrect or incomplete, decisions may be taken at this time which can impact the design response of the project.

For rural sites, the understanding of natural systems and specific site conditions can help one develop an appropriate design response. As an organisational tool – the site may be seen in through 2 distinct lenses  – 1 the natural world and 2 Buildings – and the rules, regulations, expertise and processes that will together contribute to achieving the design objectives

The information and data collected and compiled must also be subjected to a process of critical analysis in order to determine which aspects hold particular relevance for individual projects.

The need to better understand climate projections and their impacts has become painfully clear The degree to which new buildings are designed to be adaptable to meet these challenges is not yet mandated but as recent climatic events in British Columbia have demonstrated, many areas are increasingly vulnerable to the effects of climate change.

Types of  Knowledge and Understanding:

These two approaches – Scientific Ecological Knowledge SEK and Traditional Ecological Knowledge (TEK)

represent 2 very distinct world views.

Scientific Ecological Knowledge (SEK)

The process by which land has been regulated, divided, and studied and developed follow long-established processes of our civil society in Canada. These processes, which include our education and governance systems guide the design and construction of buildings and infrastructure. Our view of the natural world and the way we understand it is shaped by our education system of which the Scientific Method is an integral part. Our education system encourages and values specialization within each discipline. Ecological systems rarely “fit” within such specialized disciplines, leading to fragmentation and siloization of knowledge .

Recent technological innovations in measuring and recording the existing condition in the Natural World include the use of drones and sophisticated digital data acquisition / interpretation. Use of these technologies is revolutionary and makes available a much finer  level of granularity of bio-geo-physical data than is possible at much lower cost and effort than with traditional on-the-ground survey and site assessment techniques.

Traditional Ecological Knowledge (TEK)

The United States Fish & Wildlife Service defines the term Traditional Ecological Knowledge, or TEK, as   “used to describe the knowledge held by indigenous cultures about their immediate environment and the cultural practices that build on that knowledge.”

See https://www.fws.gov/nativeamerican/guides.html

The value local intimate knowledge of place gained over centuries is now starting to be recognized and valued.

Components of a Predesign Investigation:

A detailed investigation could include the following:

The Natural World

1. Natural Systems: Research and document the Bio Geo Physical Attributes of the site
   1. Geology
   2. Hydrology
   3. Site Ecology
   4. Natural Resources (Ecosystem Services) available at the site -What are they and how can / should the design respond /incorporate these resources?
      1. Climate: Temperature, weather patterns, wind,
      2. Solar potential
      3. Water Resources
      4. Environmental
      5. Climate change: temperature, climate threats, adaptation

What are Ecosystem Services?

Wikipedia defines Ecosystem services as “the many and varied benefits to humans provided by the natural environment and from healthy ecosystems. Such ecosystems include, for example, agroecosystems, forest ecosystems, grassland ecosystems and aquatic ecosystems. These ecosystems, functioning in healthy relationship, offer such things like natural pollination of crops, clean air, extreme weather mitigation, and human mental and physical well-being. Collectively….. known as ‘ecosystem services’, and are often integral to the provisioning of clean drinking water, the decomposition of wastes, and resilience and productivity of food ecosystems.

Buildings and Design:

1. 1. Bio-cultural Use of the site and vicinity:
      1. history of how the site has been inhabited and used, including current uses
      2. site organization
      3. movement systems: vehicular, paths, trails
      4. use and disposition of existing buildings and infrastructure systems,
   2.  Design
      1. applicable codes / regulatory regime
      2. Define environmental performance objectives appropriate for the project and the site

Ecosystem Services and Design strategies: Utilizing the Natural Resources available at the site

Solar Energy   

The sun is the primary source of energy available. As explained in Chapter 2, the amount of energy that reaches our planet’s surface is vast- the amount of  raw solar energy that the earth  receives each day exceeds the total energy use wordwide!1

With costs of components of solar photovoltaic systems dropping rapidly in recent years, it has become much more affordable to include renewable solar systems. Achieving net zero

Accessing Solar Energy

Photovoltaic systems convert sunlight directly to electricity. Although the technology has existed for decades, the cost of these systems has remained high enough to discourage use. Recently these costs have dropped significantly with increasing supply and demand making the use of this technology possible on many projects.

Panel Types:

Two main types of solar PV Panels available are crystalline and thin film. Crystalline Panels are available in Mono & Poly crystalline modules which are formed from silicon. Mono crystalline panels are rated highest in efficiency but are more costly than the slightly less efficient poly crystalline panels. Thin film PV are found in various building & other products such as roofing and cladding  but are less efficient but operate with different characteristics than the crystalline products.  https://www.buildinggreen.com/product-guide/solar-photovoltaic

2 https://www.buildinggreen.com/feature/five-reasons-be-optimistic-about-solar-energy

Overshadowing part of an array of panels can affect overall performance  dramatically depending on how panels are configured due to differences in how string of panels can be connected. In older systems, the entire string of panels connected in series could dissipate any electricity being generated by to the panels in shade. New string inverters and power optimisers –which limit lost energy to just those parts of the panel in shade are now available. Refer to https://www.solarchoice.net.au/blog/partial-shading-is-bad-for-solar-panels-power-systems/ for an explanation of these performance issues.

Other system considerations:

The solar panels are just one component in a complete system which includes an inverter and possibly  a battery storage system. PV panels produce DC electricity which inverters convert to AC power to be compatible with the grid and the building’s AC electrical system. If the building is to be grid tied, incorporating batteries to the system can play an important role by enabling the storage of some of the electricity being generated for later use.

Batteries for Buildings

With the development and greater production of large battery systems for Electric Vehicles, batteries for designed for buildings by several manufacturers have become widely available. See https://www.buildwithrise.com/stories/2019-guide-to-the-best-home-battery-storage-options

Solar Thermal

Solar Thermal systems are a proven technology that has been commercially available and in usage for over 20 years in North America.

Utilizing solar energy to heat water is far more efficient than converting it to electricity, with PV panel efficiency remaining close to 20%. A direct cost comparison indicated that for an equivalent panel area, the equivalent energy output of solar thermal outperforms solar PV by a factor of almost 6:1. https://www.buildinggreen.com/feature/solar-thermal-hot-water-heating-and-cooling

Solar thermal systems come in different configurations and typically include:

• Solar collector: There are 2 types of collector systems available – flat plate and evacuated tube – both of which offer similar performance.
• Storage Tank: For northern latitudes, the storage tank is located indoors to avoid any risk of damage from below-freezing temperatures.
• Heat transfer Medium

Building Integrated PV

Photovoltaics can be integrated into many building products with the use of thin film PV. These solar panels are made of thin films of semiconductors deposited on glass, plastic or metal. These different substrates offer different properties and can be integrated into many different products such as roofing tiles, glazing units. Efficiencies are a bit lower than the crystalline but are more efficient at lower light levels.

For a comprehensive e review of solar thermal see: https://www.buildinggreen.com/feature/solar-still-active-water-heating-and-other-solar-thermal-applications

Refer to Chapter X for an overview of related applications on line tools to work with solar energy and lighting.

Daylight:

Artificial lighting has created the ability to design interior space without concern over the quality or quantity of natural light available. Studies have shown that access to daylight has been shown to improve cognitive ability and the attributes and benefits of daylight are well recognized in green building ratings systems such as LEED and WELL.

Daylighting can also reduce energy for lighting during daylight hours but the extent of glazing and its performance (U value, emissivity, solar heat gain ) must be factored into an energy performance model. Increasing levels of energy performance can mean that the area of glazing must be limited if energy targets are to be achieved.

Daylight modelling applications can also provide much insight into how interior spaces will be naturally lit and can predict levels of illumination with great accuracy. The Lighting Design Lab, associated with the University of Washington has developed many years of expertise in daylighting. See Introduction to Daylighting for an in depth explanation of how to integrate daylighting into the architectural design process

For an overview of daylighting, wellness see Lighting Design for Health and Sustainability: A Guide for Architects

https://www.buildinggreen.com/feature/doing-daylighting-right

Air

Natural Ventilation

As mentioned introduction, the advent of mechanical systems – Heating Ventilation & Air Conditioning (HVAC) enabled the design of much larger buildings and the accommodation of many air-intensive fucntions not possible without the functionality that these systems offer.

The requirement to include mechanical ventilation is now embedded in building codes for all building types in Canada – these requirements ensure a minimum rate of ventilation and fresh air related to occupancy.

Natural Ventilation offers advantages over mechanical air supply systems but the code mandates that the mechanical system be capable of meeting minimum ventilation and air quality  requirements. This can mean that design strategies using principles that enhance natural ventilation are in addition to those required by code and may result in additional capital cost.

The integration of design elements that are intended to enhance natural ventilation may add costs through the presence of architectural elements such as interior voids and operable roof monitors which enable the movement of large volumes of air and operate on the principles of thermal chimneys. These costs may sometimes be offset due to lesser  ventilation equipment needs. Another challenge to address with natural ventilation is controlling indoor acoustical performance. The large air pathways which enable natural ventilation also can act as sound conduits enabling the free passage of sound.

Windows with  motorized operators for controlled by the Building Management System can be fitted with temperature and/or rain sensors to automatically manage the opening & closing of windows when exterior conditions are appropriate. These types of linked systems enable night time flushing of buildings which can save considerable cooling costs.

Why include Natural ventilation? According to Building Green the three primary reasons are Energy Savings, Occupant Satisfaction and Indoor Air Quality. With the tempering of ventilation air typically being the largest end user of energy in a building, considerable savings can be achieved if integrating natural ventilation can result in lower energy use.

Perhaps the most compelling reasons to design using natural ventilation principles are the  benefits to building inhabitants. The personal satisfaction that is associated with the ability to open a window, and gain direct access to the natural world is undeniable.

With the changes to local climate predicted to take place in the near future, the local application of natural ventilation principles may need adjustment – buildings designed to take advantage of nighttime cooling described above may no longer function as intended if nighttime temperatures rise as witnessed during the heat wave experienced in June 2021.

The requirement to include mechanical ventilation is now embedded in building codes for all building types in Canada – these requirements ensure a minimum rate of ventilation and fresh air related to occupancy.

Resources:

City of Vancouver Passive Design Toolkit: https://vancouver.ca/files/cov/passive-design-large-buildings.pdf

Water

Most areas in British Columbia have access to sufficient volumes of potable water for their needs. This abundance of supply seems to have enabled the development of a similar perspective to that described above for energy, with the result that water has been viewed as an endless resource with no need to conserve/ reuse. Water systems in buildings today remain for the most part characterized by the out-of -sight linear mindset that flushing the toilet engenders.

Buildings within rural contexts however cannot depend on centralized municipal  systems for either their domestic water needs or to process waste water, but may have to depend on site-based systems.

Domestic (potable) water may be obtained from subsurface aquifers or from water bodies on the site if present, or from rain falling on the site.

Site-based sanitary disposal systems are generally employed – these systems offer a range of levels of treatment of waste water depending on the quality of effluent that is desired.

Potable Water

For sites not serviced with potable water an on-site system must be implemented. For buildings that fall within the jurisdiction of the Building Code – the baseline condition mandated is that any water utilized by any plumbing fixture in all buildins must be potable.

What is Potable Water?

In basic terms Potable Water is water that is fit for human consumption – that levels of chemical and organic contaminants and any pathogens are controlled. Many natural sources – deep wells and springs – for example –conform to the Canadian Drinking Water Guidelines and  little or no treatment may be required.

On-site water can be obtained from  a variety of sources – most commonly from a well, although surface water and rain water may  also be used but most likely will require treatment to upgrade the quality to meet the Standard.

Treatment processes includes filtration, exposure to ultra-violet light and may also include the addition of chlorine.

Societal Attitudes towards water

Water-borne disease has had a major impact on how our society views water. Our water standards  – and resulting regulations and codes govern our use and manner of contact with water are based on the concept that there are just two qualities of water – Potable, and Effluent. In reality many qualities of water exist, with Potable being the highest use and most costly to procure.

These standards create the situation that since  only potable water is available from municipal systems, this water is also used for purposes such as flushing the toilet, watering the lawn and washing the car.

For stand-alone water systems on remote sites, harvesting other sources of water for non-potable end uses may allow potable treatment systems to be downsized.

Waste Water Treatment:

Taking an environmentally sensitive approach to the design of both building and site includes treating wastewater to a suitable standard and considering water reuse for a range of non-potable applications if appropriate.

1. Septic Systems overview

The overall concept is to treat the wastewater generated a  water standard defined (for BC) under the BC Municipal Sewage Regulation (MSR),see

The conventional treatment process consists of:

1. Biological Treatment by bacteria to removal of biodegradable organic matter and nutrients.
2. Release of the treated water to the receiving environment

If re-use of the treated water is desired, the water must be further treated:  Tertiary treatment and Disinfection is needed to remove disease-causing microorganisms.

The wastewater treatment system design involves three components: 1) wastewater characterization; 2) analysis of the receiving environment where treated wastewater is to be discharged and 3) technology / equipment selection.

Wastewater characterization involves understanding where the origin of the wastewater, types and quantities of contaminants and the amount of wastewater and variations in flow. The receiving environment conditions determine what options are available for dispersal or reuse and the quality of water that would be discharged.

Once these variables are confirmed, an appropriate system can be selected to perform as needed.

In practice there are three levels of wastewater treatment defined by the BC Sewerage System Regulation. The majority of residential stand-alone systems treat their wastewater to primary level. On sites where poor drainage conditions exist,  or a higher level of treatment is required, treatment  to levels 2 and 3 provide a much higher quality of discharge and reduced the  drainage field area required.

Once these performance requirements – the volume of waste water and level of biological matter present that is expected to be generated – have been defined, the system can be selected that best removes the contaminants from the wastewater to achieve the necessary water quality and meets operational objectives.

Domestic wastewater originates from a number of sources including toilets, kitchen sinks, bathroom fixtures –  sinks, bathtubs and showers, laundry wash-water. This wastewater can be characteristically divided into three sub-categories roughly related to the the concentration of contaminants contained in the wastewater: 1) blackwater; 2) dark-greywater, and 3) light-greywater.

Blackwater is the most contaminated level – including toilet water,  and other and contains high levels of organic contaminants as well as high numbers of potentially disease causing microorganisms.

Dark greywater primarily originates from kitchen sinks and food preparation areas, and can also have high levels of organics contaminants from food waste and grease/oils, in addition to microorganisms.

Light greywater typically consists of drainage from bathroom sinks, tubs, showers, and often laundry. It can also contain disease-causing microorganisms but typically in much lower numbers than the other two wastewater categories.

One consideration for site-based waste water treatment and disposal and re-use systems is that unlike the central systems whatever goes down the drain remains on the site. This could be significant if care is not taken with cleaning or sanitizing products being flushed down sinks or drains. these products contain a vast array of chemicals many of which  can affect the functionality of the treatment system and introduce chemicals into the re-used water supply.

Wastewater treatment approaches range from simple septic tank systems, to highly complex and costly advanced biological treatment processes incorporating special tanks, bioreactors, filters, pumps and disinfection systems.

There are a wide number of wastewater treatment systems available.

Living Machines:

Systems which utilize living plants set within greenhouses or in constructed wetlands are an alternate treatment for all or part of a wastewater  treatment system. Conventional systems utilize bacteria to consume organic material in wasterwater, which is similar to how the Living Machine systems also function.

According to the organization  Engineering for Change (E4C)   The Living Machine is a form of ecological sewage treatment based on the principles of wetland ecology“

https://www3.epa.gov/npdes/pubs/living_machine.pdf

Water Re-Use

Re-used water  may be used for a variety of non-potable water applications including dust control, vehicle washing, toilet & urinal flushing, laundry, landscape and edible crop irrigation, fire suppression, and stream augmentation.

All instances of water reclamation and  re-use must meet the national (Health Canada) guidelines for water reuse. The treatment systems have been selected to ensure the reliability and robustness of the process while minimizing the energy and labor requirements.

Climate change

The climate in the Lower Mainland of BC is expected to change significantly over the coming decades.

According to the Sixth Assessment report issued by the Intergovernmental Panel on Climate Change (IPCC) for the Central and Western North America – the type of climate related events that have been experienced in British Columbia in 2021 are expected to increase – see

https://www.ipcc.ch/report/ar6/wg1/downloads/factsheets/IPCC_AR6_WGI_Regional_Fact_Sheet_North_and_Central_America.pdf

For the design of new buildings the projected changes to the weather and climate present new challenges that cannot be ignored. The intensity and duration of rainfall events, the type of extreme heat event and subsequent wild fires experienced in British Columbia 2021 have demonstrated the climate uncertainty that lies ahead, and exposed the  urgency that exists around this design driver

Adaptation and Mitigation

According to the Natural Resources Canada,

“Climate change adaptation refers to actions that reduce the negative impact of climate change, while taking advantage of potential new opportunities. It involves adjusting policies and actions because of observed or expected changes in climate. Adaptation can be reactive, occurring in response to climate impacts, or anticipatory, occurring before impacts of climate change are observed. In most circumstances, anticipatory adaptations will result in lower long-term costs and be more effective than reactive adaptations………..Mitigation is necessary to reduce the rate and magnitude of climate change, while adaptation is essential to reduce the damages from climate change that cannot be avoided.”

For additional information on the impacts of Climate Change in rural and remote communities see:

https://changingclimate.ca/national-issues/chapter/3-0/

https://www.nrcan.gc.ca/climate-change/impacts-adaptations/10761

Current Practice:

It is still common practice for the design community to design new projects using past climate data.

As demonstrated by the Heat Dome event  experienced in British Columbia in June 2021, despite the fact that our climate is warming with longer and hotter summers predicted and warmer & wetter  winters predicted for the south coast of British Columbia. Both the recent extreme heat and the recent flooding events have clearly demonstrated the vulnerability that exists where the design of infrastructure is outdated and the physical infrastructure becomes overwhelmed. The existing flood suppression infrastructure (dikes and pumping stations) could not manage the volume of water inundating the region, and many people perished in the extreme heat which proved fatal to some who did not have access to conditioned air.

Extreme Heat: Designing buildings with incorrect climate data Practice can result in overheating of the interior of buildings  which resulted in dangerously high indoor temperatures during the recent heat wave. Warmer summer temperatures also diminish the  effectiveness of cooling strategies that rely on nighttime air to cool buildings down.

Extreme Rain Events:

The design of building systems and site drainage to manage water flows resulting from rain events has been based upon  historic climate records. With warming temperatures the atmosphere has an increase capacity  of carry water vapour, which results in increased rain events. The increased water runoff may cause localized flooding and storm water systems must be sized to meet the increased flows expected.

Wildfire:

Buildings on rural sites may  face an increase threat from  climate-wildfires – many buildings were lost in the wave of recent forest fires that occurred  after the heat wave had dried out. The BC Government Firesmart program has developed a series of recommendations for the protection of buildings in rural settings.

See https://firesmartbc.ca, for information on prevention strategies for the areas around buildings and materials that can offer higher levels of resistance to fire.

BC Housing has developed the Mobilizing Building Adaptation and Resilience (MBAR) project –

MBAR is a multi-year, multi-stakeholder knowledge and capacity building project led by BC Housing, with participation and contribution from over 30 organizations, including national, provincial, and local agencies; and industry partners. See

https://www.bchousing.org/research-centre/library/residential-design-construction/MBAR&sortType=sortByDate

MBAR has  developed a series of resources to address climate change impacts to buildings and sites, and provide guidance, including for

• Air Quality
• Chronic Stressors
• Wildfire
• Flood Events
• Heat Wave
• Seismic Events
• Severe storms

Building Materials: what makes a building material green?

The selection of building materials to incorporate into a project is a complex process, that may take into account many factors including cost, performance, embodied carbon and life cycle analysis, toxicity.

The building materials industry is a major contributor to environmental degradation through the extraction and, harvesting of natural resources and the manufacture of construction materials and products.

Evolving design concerns around the design of buildings to minimize embodied carbon and emissions  resulting from building operations are having a profound impact in the selection of building materials and systems as are health concerns over the chemical compounds found within many building products and finishes.

This section is meant to provide a brief overview of the environmental aspects of material selection  for the designer to consider.

Material Considerations:

Performance: Energy and water

Energy and water consumption have been long been identified as 2 areas where improvement in the performance of individual products would lead to reductions in consumption which in turn has been viewed as an important objective. Other issues including carbon and Life Cycle – have emerged which have displaced efficiency as the considerations of prime importance.

For example – many insulation products are hydro-carbon based foamboard – which offer industry leading thermal efficiency. However – If other attributes are factored in – such as the embodied carbon content of the foamed plastic, products such as Extruded.  Polystyrene and Polyisocyanurate  contain many times the embodied carbon as cellulose or wood fiber insulation products.

Responsible Sourcing:

LEED has long recognized responsible sourcing (harvesting, extraction, manufacturing processes of proposed materials) as an important criteria for the selection of materials and as a result industry has become familiarized with providing environmentally relevant information about their products and processes.

Embodied Carbon:

Understanding and calculating the amount of embodied carbon within a building’s design has become an important metric is understanding the level of total performance of a building projected over its lifetime. The practice of reducing embodied carbon is in its infancy. Refer to the following links to industry leading current references.

Canada Green Building Council has produced two documents with the intent  to help accelerate the transition industry towards achieve carbon emissions.

Zero Carbon Building Standard: https://www.cagbc.org/cagbcdocs/zerocarbon/v2/CaGBC_Zero_Carbon_Building_Standard_v2_Design.pdf

Zero Carbon Performance Standard:https://www.cagbc.org/cagbcdocs/zerocarbon/v2/CaGBC_Zero_Carbon_Building_Standard_v2_Performance.pdf

The Rocky Mountain Institute’s research indicates that:

Buildings account for at least 39 percent of energy-related global carbon emissions on an annual basis. At least one-quarter of these emissions result from embodied carbon, or the greenhouse gas (GHG) emissions associated with manufacturing, transportation, installation, maintenance, and disposal of building materials.

See https://rmi.org/insight/reducing-embodied-carbon-in-buildings/

Embodied carbon for materials includes the carbon emitted associated withraw material extraction, manufacturing, and transportation.

The Carbon Leadership Forum, together with the American Institute of Architects has published this guide to reducing Embodied carbon in buildings:

https://carbonleadershipforum.org/clf-architect-toolkit/

Architecture 2030 has developed its Carbon Smart Materials Palette

CARBON SMART MATERIALS PALETTE

Consider replacing materials with alternates that have lower embodied carbon: for example replacing structural steel and concrete where appropriate with lower embodied carbon mass timber products can be significant reduction, due to the carbon intensive extraction / refinement / manufacturing that steel requires.

As overall building performance increases and approaches net-zero energy consumption, the carbon associated with operations becomes less significant compared to that which is embodied in the building materials.

Life Cycle Analysis (LCA):

Understanding the impact a building imposes on the environment over its entire life has emerged as a wholistic and meaningful way  to assess these impacts to the environment including human health

Understanding the quality, severity, duration of a building’s impact.

An LCA analysis – an analysis of  a building’s materiality and operations  over its entire projected lifespan  – includes material components and assemblies, the construction process, its emissions over its working life and those  related to its  end-of-life (disassembly and disposal and or re-use)

The Carbon Leadership Forum has published Life Cycle Assessment of Buildings: A Practice Guide

See https://www.carbonleadershipforum.org/wp-content/uploads/2018/06/CLF-LCA-Practice-Guide-v1.0-2018-06-28.pdf

Carbon emissions (embodied and operational) as illustrated below have been identified as a meaningful means of measuring performance over the entire life of a building

This category includes products / equipment that contribute to: the overall performance of the building, reducing heating and cooling loads, reducing water requirements.

Materials and equipment may also be evaluated on the basis of the contribution that is made to achieve design objectives such as efficiency in operations, performance, durability.

Toxicity and Chemical Transparency:

Buildings should be healthy places for people and for the ecology of the site that surrounds them. In order to provide a way to better understand what chemicals are contained in any given product – different  chemical transparency frameworks have been developed.

1. Material Safety Data Sheets: MSDS

According to the Canadian Centre for Occupational Health & Safety,

A Material Safety Data Sheet (MSDS) is a document that contains information on the potential hazards (health, fire, reactivity and environmental) and how to work safely with the chemical product… It also contains information on the use, storage, handling and emergency procedures all related to the hazards of the material. See https://www.ccohs.ca/oshanswers/legisl/msdss.html, retrieved on Nov 11, 2021

All materials identified by the WHMIS Workplace Hazardous Materials Information System must each have a MSDS sheet, which are prepared by the manufacturer of the product in question.

In the construction process, MSDS sheets primarily apply to chemicals, adhesives, coatings etc that are site applied.

2. Health Product Declarations (HPD): see https://www.hpd-collaborative.org

A Health Product Declaration (HPD) is a document that discloses product ingredients and associated health hazards. In response to increased interest around health impacts of  buildings and building materials the HPD was created by the HPD Collaborative.

The HPD provides a framework for product manufacturers and their ingredient suppliers to report and disclose information about product and associated health information. The HPD Open Standard is a not-for-profit member organization.

3. The Living Building Challenge and the Declare program:

The LBC Materials Petal includes 2 Imperatives that directly address materiality:

Imperative 13: Red List see https://living-future.org/declare/declare-about/#the-red-list. The LBC directly identifies  – on its Red List – the list of chemicals and or products that cannot be included in a Living Building. The Red List is a short list of products whose use is prevalent within the construction industry. The intent of the red List is to eliminate or avoid impacts related to the use of these worst-of-class products – which include polluting the environment, exposing workers who come into contact with these products to harm, and avoidance of bio-accumulation of chemicals in the food chain. The LBC also recognizes third-party sustainability standards.

Imperative  11: Select building materials and products from the Declare program

The Declare Program: see https://declare.living-future.org

The Declare CC, is a database of materials and products created by the International Living Future Institute designed to complement the Living Building Challenge’s Red List.

4. Materials transparency & risk for architects:

The American Institute of Architects has published Materials transparency & risk for Architects

https://content.aia.org/sites/default/files/2016-04/Materials-transparency-risk-architects_0.pdf

This document reviews important questions around material use, transparency, and practice + professional liability concerns.

Materiality and site ecology:

a brief overview of some common building materials / assemblies / systems  which interact in many different ways with the ecology of the site in which the building is located.

The vast majority of products in buildings do not actively interact in negative ways with the surrounding environment , however there are a few classes of materials which bear mentioning. As the building envelope is the physical interface between the building and  its surroundings – this is where most of these products and materials are found.

Metals:

the presence of metals in even extremely small concentrations can be toxic to many life forms. Some commonly used metals are used in many readily available products:

Corten Steel: The rusted steel product is utilized in many cladding and other applications. The rust layer – which is a protective coating for the underlying steel does leach if water comes into contact with it. https://pubmed.ncbi.nlm.nih.gov/26995453/

Zinc: Zinc has well known toxicity properties. Zinc strips are commonly used on roofs to inhibit the growth of moss.

Copper: copper roofing also leaches copper into rainwater – copper like zinc is a herbicide

Roofing Materials:

https://www.bluebarrelsystems.com/blog/roofing-materials-for-rainwater-harvesting/

There are many different products available to utilize for roofing – there are a few concerns that the designer should be aware of regarding the possibility of chemicals present in runoff and its  re-use for irrigation or potable end uses, or potential impacts of its release to the receiving environment.

Galvanized Steel and zinc: Commonly used for roofing and metal siding: https://pprc.org/wp-content/uploads/2014/09/Emerging-BMPs_Galvanized-Roofs_2014.pdf. Similar to steel, zinc and galvanized steel products leach zinc oxide. Zinc is a herbicide.

Bituminous Roofing:  This class of roofing products include torch-on products – modified SBS roofing as well as asphalt shingles. 

According to Environment Canada, Asphalt products which include bituminous roofing https://www.ec.gc.ca/ese-ees/default.asp?lang=En&n=802930A1-#toc-02 do leach chemicals , but due to their  low water solubility, rainwater runoff but is generally considered not a concern. , unless the water is to be used for potable purposes and /or irrigation of food crops.

Wood/Cedar Shake / Shingles – These products may contain chemicals that have been added to inhibit fungal growth as well as fire retardants. In general, caution should be used if water is to be harvested and used for potable and/or irrigation purposes.

See: Common roofing materials and water quality considerations

https://stormwater.pca.state.mn.us/index.php/Water_quality_considerations_for_stormwater_and_rainwater_harvest_and_use/reuse

n be used for rainwater harvesting systems that are for irrigation use only. These tend to leach contaminants and retain mold and algae which make it impossible to use for whole-house potable use.

Wood Preservatives:

The purpose of wood preservatives is to inhibit deterioration and degradation of wood products due to fungal growth and attack from insects and other pests. Considered a pesticide, the use and application of preservatives  products must be registered  as the potential impact to the environment is of concern.

The US EPA has published detailed information on wood preservatives – see https://www.epa.gov/ingredients-used-pesticide-products/overview-wood-preservative-chemicals.

Copper is a key ingredient in many preservative products. One common use is as a component in the preservative  solutions uses to pressure treat wood. Alkaline copper quatenary (ACQ) is the most commonly used treatment in resdidential applications, Copper azole, Copper naphthenate are other commonly used preservative products.

Treated wood should not be disposed of with other wood products and should not be burned.

For more information

Glazing:

An astonishing 10,000 birds annually die as a result of colliding with buildings at UBC  https://sustain.ubc.ca/bird-friendly-design

– a stark indicator that collisions with buildings are a major contributor to bird mortality.

Fatal Light Awareness Program (FLAP) Canada is a registered Canadian charity recognized as an  authority on the bird-building collision issue has developed  BIRD-SAFE DESIGN AND STANDARDS

Guidelines see  https://birdsafe.ca/design-standards/

Strategies to limit impacts during construction

Sites where the natural world is still present are also much more vulnerable to impacts related to construction activities and care should be taken to examine how best to proceed  to minimize impacts during construction resulting from construction activities.

The development of any infrastructure needed – roads, water, electrical, sanitary system –also can have significant impacts and care must also be taken when designing these systems. If infrastructure improvements are contemplated, The related aspects of the site analysis study should be executed to a level that will  enable the services to be located and aligned as much as possible with the existing natural systems on the site.

Refer to Chapters 2 and 3 for more information on the new digital tools that are available to help collect and interpret site specific geo-physical and biological  information and data.

Design Strategies:

1. Building upon the Predesign Site Analysis:

The importance of understanding the conditions at the site cannot be overstated.  In addition to study of the conventional site attributes of topography, site boundaries, zoning requirements and context analysis needed in more urban environments, studying a natural site can provide the basis  for the designer to respond meaningfully to the ecology of the site. By definition, the full range of services  typically provided for urban sites – including potable water, sanitary waste and electricity and/or  natural gas , may not be available at a rural site.

Gaining a detailed understanding of the current and future climate, the sun and opportunities to harvest solar energy,  as well as the site  ecology will help develop an understanding of the opportunities and ecosystem services that the site may have to offer.

In this age of climate uncertainty the design of buildings will need to anticipate future conditions. As we have witnessed significant local  events 2021 in British Columbia that have exceeded predictions including extreme heat, widespread and extreme forest fire conditions and most recently extreme rains that have caused extensive flooding and damage to infrastructure. See Section below Adaptability for a more detailed discussion of these issues.

Construction Processes: How can the Design contribute to minimizing site disturbance and overall reduce construction activity at the site?

Prefabrication and Off-site construction:

Consider off-site prefabrication of large components and assemblies. By shifting the fabrication of the superstructure and building envelope off- site, the immediate surroundings of the building will suffer far less impacts such as compaction of soils from large vehicles – common to construction practices.

There are 2 basic approaches – volumetric and panelized

With a volumetric design, more completely finished sections of building are possible, in “chunks” that are joined together at the site.

Building components are in general – limited to the maximum clearances that can easily be transported by conventional trucks on the road system. highway overpasses (4.51 m) and maximum width and length dimensions allowable, impose strict dimensional constraints on volumetrically designed prefabricated buildings.

Panelized designs utilize large pre-assembled wall, floor and roof panels complete with frame, sheathing and thermal insulation that can quickly be erected on the site. Panels dimensions can range up to 3.3 m in width and over 12 m in length.

Both systems do utilize large cranes to hoist the prefabricated assemblies into place, requiring an engineered  crane pad and sufficient clearance for the crane to operate.

The interiors and Mechanical/Electrical /Plumbing /systems may be completely installed in Prefabricated Volumetric buildings. While it is possible to incorporate service rough-ins within individual panels connecting these between panels requires a high degree of design and coordination.

Natural Systems and Regenerative Design

Biologists and other professionals have much to offer to the design & construction practitioners about how to respect nature and what steps might be taken to minimize disturbance, and to mitigate / regenerate any damages that have occurred.

Maintaining Biodiversity,

According to the Audobon Society regarding the question of Why Native Plants Matter

Restoring native plant habitat is vital to preserving biodiversity. By creating a native plant garden, each patch of habitat becomes part of a collective effort to nurture and sustain the living landscape for birds and other animals.

See https://www.audubon.org/content/why-native-plants-matter

1. Site Work:
   1. Conventional site construction practices

Conventional site construction practices typically focus on efficiency and expediency. Work on the site is expensive, particularly if machine time is involved, and this drives much of current site development construction practice including  the clearing of the site,  installation of infrastructure & services and excavation work.

Changing Practices:

With the advent of LEED and strengthened with each iteration , which included measures to mitigate some of the. most damaging impacts of common construction practice. The current version of LEED – V.4.1 – includes a key  prerequisite

 `                CONSTRUCTION ACTIVITY POLLUTION PREVENTION:

Intent: To reduce pollution from construction activities by controlling soil erosion, waterway sedimentation, and airborne dust. See https://www.usgbc.org/credits/core-shell/v20/ssp1

By requiring erosion, sedimentation and dust control measures to be implemented on all LEED projects that include site work, this prerequisite has done much to raise awareness of and implementation of basic measures that should be taken for all projects to help protect the integrity of the site where site work is being executed.

Other LEED Sustainable Sites credits that specifically encourage good environmental design practice  include:

Site Assessment

Intent: To assess site conditions before design to evaluate sustainable options and inform related decisions about site design.

Protect or Restore Habitat

Intent: To conserve existing natural areas and restore damaged areas to provide habitat and promote biodiversity.

Rainwater Management

Intent: To reduce runoff volume and improve water quality by replicating the natural hydrology and water balance of the site, based on historical conditions and undeveloped ecosystems in the region.

1. Scheduling

The natural world has its own schedule. At certain specific times of year activities that impact the ecology of a place may be regulated.

The nesting season curtails most construction activity that involves the removal of trees. The quality of habitat sought by spawning fish can be greatly impacted by construction activity that creates run-off and increases sedimentation.

• Minimizing Site Construction Activity

Most aspects of most projects are completed on site, including the erection and completion of a building’s superstructure + envelope, installation of building systems and services and interior and exterior finishes.

Prefabrication can help reduce both the amount and the duration of construction activity.