Taking stock of Environmental Sustainability
As the building industry rolls out more stringent energy efficiency targets, a second very important part of how we build is on the horizon, embodied energy.
If you are thinking of building a high-performance home, do you know how much energy it takes to create it's building materials? In some cases, more energy is consumed producing those building materials than the home will ever consume in operation! With the best intentions, designers should know the full story of all building materials specified in their documents and make substitutions wherever possible.
Nothing in the construction industry is getting cheaper. We all know this is a fact, whether we want to admit it or not. As fuel prices fluctuate and eventually rise, so do the costs of our energy-intensive building materials that have been commonplace for the past decades. Without sounding like an anti-oil activist, we really should be using the last reserves of fossil fuels in a smarter manner. So, how do we dig out!? This side of the discussion is multi-faceted with subjects into energy policy, the powers of industry, willingness to change, etc.
How we see our Carbon Footprint
NIDO's aim is to place importance on both energy efficiency and materials in all of the buildings we design. This requires us to use methods and tools to audit the building materials we choose for lowering GHG (Greenhouse Gas) Emissions, a measure of tonnes of CO2 required to build a project. An understanding of Life Cycle Assessment (LCA) is also important to understand the material's longevity and future use after the service life is complete.
Here are some definitions for reference: 1) Life Cycle Analysis (LCA) An LCA for buildings focuses on resource extraction, manufacturing, shipping, site construction, service life, and eventual demolition/disposal or re-use. This has also been referred to "Cradle to Grave" or "Cradle to Cradle". Within the LCA, we can quantify GHG emissions to a measure of CO2, and take a look at potential impacts on our natural environment.
2) Embodied Energy (EE) Embodied energy more specifically refers to the energy consumed creating a building material. This includes all of the processes such as mining and processing of natural resources, manufacturing, transportation, and product delivery.
The Life Cycle Analysis tools we use...
The methods and software to carry out an LCA are constantly evolving and here at NIDO we are aligning our design process with Athena to produce the data we need to weigh our options on material selection.
There are many other software platforms available to the industry, depending on what kind of information needs to be produced.
How we all create greenhouse gas (sorry cows)
For most of the residents of planet Earth, our daily activities, habits and consumption contribute to the production of greenhouse gas through use of Energy, plain and simple. (I know, it's a bummer). This most definitely includes building materials, too. The scientific community's preferred unit of measuring Energy is typically (Mega Joules) MJ. For some perspective on this, let's convert to electricity and compare it to your monthly power bill...
1 MJ (Mega Joule) = 0.28 kWh (Kilo Watt Hours)
For a real-life example, it takes 2.59MJ (0.72 kWh) to boil 1 litre (1 kg) of water from room temperature and it takes 0.1 kWh to toast a piece of bread.
The Embodied Energy of kiln-dried dimensional lumber, is approximately 2.5MJ (0.695 kWh) / kg. A single piece of 2x4x8' long weighs 4.95 kg, which means it has taken 3.44 kWh to produce.
The next step is to wrap our head around energy consumption in relation to greenhouse gas emissions and natural habitat disturbance, there is a unit of measurement for that too! The unit is called "Consumption Intensity" (g CO2 eq / kWh). This means grams of CO2 produced per kWh consumed. Depending on where you live in this world this value will differ.
Here in Canada we averaged 40 g CO2 eq produced / kWh used in 2016
Quebec had the lowest at 1.7 g CO2 eq / kWh, mostly offset from their extensive network of hydro producing dams.
Alberta had the highest at 900 g CO2 eq / kWh since the fossil fuel energy sector is such a large consumer of electricity.
Canada's annual publication titled the "National Inventory Report" (NIR) is publicly available on the UN's climate change website. Many other countries submit reporting to the UN in a similar format.
OK, let's talk materials
Some building materials will have a very high Embodied Energy but very little weight is required while other materials will have a relatively low Embodied Energy but massive quantities are required. The smartest choices in materials are those that can don't require too much energy to create and can capture or store carbon over their service life. Beyond that, re-using or up-cycling adds that much more value to a material or product. For the most part, these are plant-based materials with low embodied energy.
Here is a list of Low Embodied Energy raw building materials that we're already familiar with:
1) Timber, sustainably harvested Framing, Flooring, Trim, Sheet goods
2) Wood Fibre Hardboard Doors, Insulation, Sheet goods
3) Hemp Fibre & Oils Masonry Units, Insulation, Wood stains & preservatives
4) Cork Flooring, Insulation
5) Cellulose (waste paper fibre) Insulation
6) Straw & Waste Agricultural Fibre Insulation, Sheet goods
7) Bamboo Flooring, Sheet goods
8) Fly Ash (coal combustion by-product) Cement additive, Tiles, Masonry units
9) Rammed Earth Walls
10) Pretty much anything Reclaimed and up-cycled or safe for re-use!
Here is a list of Low Embodied Energy building products that stand out:
1) ReWall Panels, USA (Recycled milk cartons)
2) BioFiber Blocks, Canada (Hemp Fibre)
3) Carbon8 Aggregate, UK (Air pollution particles)
4) Enviroshake, Canada (Recycled composite roof tiles)
6) BioMason Tiles & Bricks, USA (Bacteria Grown Cement)
7) ABT Insulpanel, Canada (Compressed Agricultural Fibre (CAF) Waste Straw Panels)
8) BYBLOCKS, USA (Plastic Waste Blocks)
9) Gypsum Board, North America (Drywall)
*Production of Gypsum Board from raw materials requires a great deal of energy but most North American products contain close to 90% recycled content. The gypsum board recycling process does not require the use of kilns, which significantly reduces embodied energy.
10) MycoComposite Panels from Ecovative, USA (Mycelium Roots)
*Mushroom root building materials & processes are still under development and we're excited to follow the progress! I mean, seriously, mushrooms?! ...cool.
A shot of Inspiration
To end things off, We'd would like to give credit where credit is due. Chris Magwood, of the Endeavor Centre Sustainable Building School, has given us a new way to think about the materials that go into a building. This past November 2018 I attended the Passive House Canada Conference. It's always a treat to be in a crowd of professionals who care about design and construction in the same ways as you! Among the many inspirational and informative presentations, Chris' presentation called "Footprint" really stood out to me. He is also the author of an incredibly informative book called "Makng better buildings". This book is literally sitting on our board room table...
Find out more about Chris and the Endeavour Centre here:
Innovative Learning, Building, Living
Contractor, Author, Teacher, Researcher, Speaker A Superb Presentation (from YouTube)
What is NIDO doing today?
We're not perfect (yet) but we're giving it our best. The major assemblies in the buildings we design have been scrutinized many different ways. Foundations, floors, walls and roofs are sandwiches of building material products and we want to strike a balance between a few factors. We ask ourselves these questions all the time:
Living Future Institute Red List Compliant How healthy is this product for us and the Earth's ecosystems? How did the production process impact our environment?
Low Embodied energy How much energy did it take to produce the product, get it to site, install it and remove it years down the road.
Durability and Longevity Will this product stay intact during installation and have a long service life?
End of life use Can this product be recycled, re-used, re-purposed, up-cycled?
Affordability Is this product going to fit in a project's budget?
Availability How easily can this product be obtained?
Industry knowledge and uptake Do trades know how to put this stuff together!?
So far, we've successfully incorporated sustainable harvested timber, wood-fibre products, cellulose, fly ash and recycled materials on many projects. Here is a shining example we are proud to be a part of:
Completed Summer 2019
We are still trying to reduce our reliance on foam and concrete products and always pay close attention to occupant heath and indoor air quality, but we'll save that for another blog post!
Clark Webb
Certified Passive House Designer, Architectural Technologist
NIDO Design Inc.
High Performance Modern Home Design
Kelowna, British Columbia, Canada
Resources
1. Making Better Buildings, Chris Magwood, March 2014
2. Athena, Life Cycle Analysis Software
3. UN National Inventory Submissions 2019, United Nations, Climate Change
4. The Red List, Living Future Institute
5. Environmental Product Declarations, Certainteed