Lecture 3 - formwork - mostly Eucalyptus wood - increase “Rapidly Renewable” Materials: - Embodied energy - one of the key factors

- Embodied energy - one of the key factors used to

Sustainable - Appropriate Materials deforestation - natural, non-petroleum-based building assess the sustainability of a construction material
Ethiopia Material and Technology - Materials need to be part of the first materials or product.
increasing awareness for the urgent need for thoughts of a building design! - harvest cycles under 10 years - Sustainable materials and products have low levels
more affordable housing - solutions still missing. - The design is essentially linked to its - Examples: of embodied energy.
- building materials are about 60 to 65% of material. bamboo, hemp, straw, cork, natural linoleum - Materials with high levels of embodied energy are
construction cost – cost of conventional building products, wool, wheat, cotton generally not sustainable and should be avoided
materials are constantly rising - out of the reach of Material Choices New Material: where possible.
large segments of Ethiopia’s population SUSTAINABLE MATERIAL: use of renewable material preferable
- adequate houses - beyond affordability for - material considerations for structure, building Recycled materials: The five main groups of natural and processed
Ethiopia’s low income population envelope, interior finishes a possible good choice,or the use of materials with a building materials - in terms of embodied energy:
(about 30-35%) - from the start of the project significant recycled content (downcycling – if the - renewable materials (timber, wool, straw, etc.)
- need for cost-effective building materials at - are less harmful to the environment quality of a recycled product is reduced – example: - extracted or mined (earth, mud brick,sand and
decentralized locations, to save transportation costs - use less energy (harvesting, processing, transport plastic) gravel, etc.)
- introduction of appropriate construction and maintenance) Reuse of Material: - extracted and further processed (lime, cement,
techniques - make buildings more efficient (climate, thermal The straight reuse of materials is preferable, plaster, slate, stone, brick, etc.)
- mostly used modern construction materials envelope, heating/cooling requirements) because it is not necessary to put additional energy - extracted and highly processed (steel, glass,
worldwide - cement, concrete, steel, bricks and - are appropriate for the specific purpose into remanufacturing. plastics, etc.)
wood - are attractive and durable Example - Reused Material - recycled or reclaimed (reused timber, brick,
- in the industrialized world, they led to comfortable “Harmful” Materials - Azkoitia Station Extension, Spain, aggregate, steel, glass, insulation, etc.)
housing and changed living patterns of the middle Interpretation of “harmful” by Estudio Beldarrain example - low embodied energy
class, but not for the majority population of - materials with toxic content - gassing off in an - reuse of railway sleepers as cladding material local oak forest -> local saw mill->local timber
developing countries. interior environment –compromise air quality, for the sculptural library extension merchant ->timber frame building
- Steel and cement - seen as symbols of wealth and causing diseases. - The Big Dig House, Lexington, Massachusetts example - high embodied energy
power - but many people cannot afford them. - harvesting materials which endangers wildlife by - infrastructural waste (steel) salvaged and reused iron ore mined mainly in australia and brazil ->
- Low cost building materials – are not sub-standard removing their habitat. (Old Growth Forests, Rain as-is for the structural system manufactured into stell in china -> shipped to
materials! Forest, etc.). Durability various countries to be used on construction sites
it include the use of locally available and local - harvesting/manufacturing of materials which - favorite the use of more durable, longlasting
developed/manufactured materials. endangers/compromises local people. materials Selecting Low Embodied Energy Materials
* locally available, locally developed/manufac- - processing or manufacturing which harm the - it is expensive to replace building - Heavyweight materials should be sourced locally.
tured materials: - environment (air pollution, water pollution, elements (windows, roofing materials, because of the high amount of fuel required to
- reduce significantly transportation costs generating waste). cladding etc.) transport heavy materials
- results in better know-how for civil engineering - products, processed or manufactured in countries - expense can be measured in: - Source for materials with a high potential for
- provide better service with cheap - costs reuse and recycling -because the embodied energy
- enhance the local economy labor costs and poor labor conditions - energy (associated with greenhouse that remains ‘trapped’ in materials at the end of a
* in Ethiopia - traditional and conventional - materials with limited resources gas emissions) building’s life should not be wasted by sending the
building materials are available - materials, difficult to reuse or to recycle energy is embodied in everything we use and materials to landfill.
- energy intensive materials - extraction or manufac- depend on - Life cycle assessment (LCA) - used to calculate the
TRADITIONAL MATERIALS ture of materials which uses significant quantities of Embodied Energy environmental impact of a material or product.
- mud, bamboo, natural stone, wood fuel, depleting fossil fuel resources and causing Definition: It considers energy consumption, Greenhouse gas
- serve the basic needs of the majority of the greenhouse gas emissions. Embodied energy is the energy needed for growing, emissions, Resource consumption, Waste, and
population harvesting/mining, manufacturing, transporting, Pollution of air, water, and land.
- provide very useful properties Non-Renewable Materials: construction, and disposal of a material. -Embodied energy and LCA need to be
- processing and construction technologies applied - metals, stones and items that ”don’t - Buildings use energy in two main ways carefully considered to specify materials and
need to be changed grow” 1. ENERGY NEEDED FOR USE: products for a project
- better quality structures and acceptance requires: - can often be recycled or reused - 2. the energy used every day when the building is - Transportation energy - significant consider-
- training of builders important to include these aspects in the occupied ation for ALL materials
- use of appropriate standards design of the construction. 3. ENERGY NEEDED FOR MATERIAL AND CONSTRUC- - sometimes it is difficult to replace materials
- a local building material industry Renewable Materials: TION: with high energy because for certain uses.
CONVENTIONAL MATERIALS - lower environmental impact 4. to extract and process the material (example: concrete, because for its thermal mass,
- Were obtained by using modern technologies, - do not use up non-renewable resources. 5. to transport the materials to the site aluminum because of durability, steel for its
developed by various researches - can be produced in large quantities 6. to build it strength)
- based on concrete pillar and slab system with - Examples: 7. to dismantle, demolish, dispose * The critical issue is - to select the best material
hollow concrete block infill wood, biopolymers (natural adhesives, for its overall use in a building and not to waste any
- huge need of cement, gravel and formwork cardboards) material.
 Key Principles to Select Sustainable Construc- Heat Storage Capacity of some Building Materials in - Natural materials, the natural site landscape and its
tion Materials kJ/kgK configuration affect the heating or cooling potential
- materials with low embodied energy Water 4182 of the site.
- materials, designed for low energy use - minimiz- Reinforced Concrete 2400 * Replacing natural surface materials with
ing the energy required to Brick 1360 “hard or impervious” materials increase the heat of
‘run’ the building. Adobe Block Wall 1300 the site.
- minimize the use of new resources (reused, Compressed Earth Blocks 1740 * The use of pervious materials allow rainwater
recycled materials, high Hollow Concrete Blocks 1400 to return naturally cleaned to the ground, without
recycled content) Sandstone 2418 directing it into the storm water systems.
- use of unprocessed materials (solid timber, natural Asphalt 1196 - choice of roofing material influences the site
stone, earth, clay, climate significantly.
natural fibers. Microclimate and Site Materials * Dark materials absorb heat, light materials
- reuse possibilities materials around the building impact the microcli- reflect the heat and are known as “cool roofs”
- contributing to a healthy indoor environment mate and the natural water runoff on the site * Green roofs stay cool, they produce oxygen,
(natural paints, natural flooring reduce the amount of water running to the sewer
material) Microclimate system, reduce urban heat island effect and
- is the “mini climate zone” on a building site and its decrease carbon dioxide levels in the city
MATERIALS - RETAINING HEAT / REJECTING HEAT immediate surroundings. The evaluation and selection of environmentally
- material with heat retention properties is useful to - Considerations must include the natural elements preferable materials and products is based on:
store the energy from the sun in the material as well as existing and future man-made elements. Performance • Aesthetics • Costs • Health •
- Materials rejecting heat are called insulation - used - Natural impacts on the microclimate: Environmental Impacts
to retard the heat flow through the building - amount of sun received
envelope - wind, natural breezes, Three basic steps of product selection
- thermal bridges - points in the building envelope - natural materials of the site
where insulation is completely lacking - must be - Artificial impacts on the microclimate: - Research:- gathering all technical information to
avoided. - paving materials be evaluated, including: manufacturers' informa-
- variety of insulation material - some are more, - roofing materials tion, building codes, government regulations…
some are less environmental harmful - wall materials - Evaluation:- involves confirmation of the technical
- landscaping information, as well as filling in information gaps,
INSULATION MATERIAL - GROUPED ACCORDING TO The color of the materials impact the temperature. request of product certifications…
ORIGIN: Light colored materials reject heat and dark colored - Selection:- involves the use of an evaluation
- NATURAL/ORGANIC INSULATION materials absorb heat. system for scoring the project specific environmen-
Cellulose, Cork, Wood wool, Hemp, Flax Sheep wool tal criteria…
- MINERAL INSULATION The microclimate in the backyards and front yards
Rock mineral wool, Glass mineral wool, foamed will be different, because of the orientation to solar
glass access and the surrounding, even if the materials
- OIL-DERIVED INSULATION used are identical.
Expanded Polystyrene (EPS), Extruded Polystyrene
(XPS), Rigid polyurethane (PUR/PIR), Phenolic foam Example:
insulation different microclimates on the front / the back of
- selection of insulation material – the house. Different materials, amount of shade and
priority should be given to its performance in the orientation to the sun
construction context, because very few insulation The front has more paving and less tree cover,
materials can perform all function. which make it hotter.
The black asphalt roof also increase the general
HEAT STORAGE CAPACITY of MATERIALS heat level of the site.
“THERMAL MASS” or “HEAT STORAGE CAPACITY” The
ability of materials to store heat, hold heat, and
slowly release it