Transcript Presentation

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Climate and Building Design
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Principles of Eco-Friendly
design
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PRINCIPLE 1. WORKING WITH
THE SUN.
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The contribution of the sun to a house’s
internal heat is called the solar gain.
A fundamental principle of solar design
is that it aims to maximize the solar
gain in the winter and minimize it in the
summer.
To achieve this solar design combines
three strategies- glazing, orientation,
and thermal mass.
Understanding how the sun
moves through the house is key
to maximizing energy efficiency.
Working with the sun.
Skylights are used to heat
and light the doubleheight bedroom and
mezzanine.
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Orientation
Orientation refers to the location of a house and direction
to which a house points.
 Only surfaces facing South receive sun all year round.
The dominant direction of the sun is from the South,
especially in winter.
 solar panels and windows that will capture solar
warming in winter, should face as close to South as
possible.
 Surfaces facing South-East or South-West receive 10%
less solar energy during the year than surfaces facing
due South..
 Surfaces facing North are in the shade all year round.
 The winter sun is low, the summer sun is high.
 Vertical
South facing windows work best for
maximizing solar heating in the winter as they capture
the low winter sun.
 We can sum up these principles to say: a well
functioning eco house will have as much of its glazing
as possible in vertical windows facing between South
East to South West, and as few windows as possible
facing North East through to North West
High performance doubleglazed windows with
wooden frames help us
conserve energy
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PRINCIPLES: 2. THERMAL MASS
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The thermal mass of the house is a measure of its capacity to store
and regulate internal heat.
Buildings with a high thermal mass take a long time to heat up but
also take a long time to cool down. Thermal Flywheel.
Eco-buildings are usually designed to have a high thermal mass.
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To hold over daytime solar gain for night time heating.
To keep houses cool during the day in summer.
In the extreme case of desert regions where daily temperatures can vary by
up to 40°, traditional houses are usually designed to have extremely thick
walls to moderate the internal temperature.
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PRINCIPLE: 3. STACK EFFECT
When air warms it expands, becomes less dense than the
surrounding air, and rises. This process is called convection
and is the main process by which heat moves around a
room and the house. When rooms are sealed, convection is
a sealed circuit of hot air rising over radiators and then
sinking as it cools to be heated again.
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PRINCIPLES: 4. THERMAL ZONING
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Thermal zoning tries to ensure the best match
possible between the distribution of rooms and the
distribution of the available heat.
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PRINCIPLE 5. EMBODIED ENERGY
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The embodied energy of a building material is the
energy that has been required to extract, process, and
manufacture it and then to transport it to the building
site. The embodied energy in the structure of a new
house is considerable, exceeding the total energy
required to heat that house for the next 20 years.
If we want to reduce the total environmental impact of a
building, we must consider the impact of the materials
that have gone into its construction. Clearly no house
can claim to be an eco-house if it is constructed from
materials that had a major environmental impact
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elsewhere.
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In terms of the energy of manufacture, the highest embodied energy is
found in metals (steel requires 57,000kWh to produce one cubic meter),
and highly processed industrial products (hardboard and MDF require
2,000 kWh to produce 1m3).
The middle range of materials are simpler to make but require a lot energy
in their manufacture (bricks and concrete blocks need 700kWh/m3).
The lowest embodied energy is in materials that require only simple
processing (building timber needs 180kWh/m3 ) or those made from
salvaged materials or local natural materials, which require virtually no
energy.
Cement and Concrete, which has a mid range embodied energy, but a
disproportionately high impact on climate change. When limestone is burnt to
make lime it releases an equal weight in carbon dioxide. Taken as a whole, the
cement industry produces 5% of the worlds human carbon dioxide emissions.
Timber has a low embodied energy, but can have a very high environmental
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impact if taken from old growth forests.
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Avoid materials that have the highest embodied energy
Use salvaged materials. Salvaged materials effectively
have no embodied energy other than transport and should
be used whenever possible. They can be obtained from
local demolition sites or council dumps.
Use local raw materials in any new building. For new
building (such as extensions), use local materials such as
local stone, straw bales, mud bricks, etc and prepare them
on the site.
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Six Decision Principles.
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ONE: THE BEST MATERIALS ARE RE-USED
TWO: ENERGY CONSERVATION HAS PRIORITY IN
THE ECO-HOUSE
THREE: ASPIRE TO SELF SUFFICIENCY
FOUR: LIVE LIKE GRANNY! ( Grand Parents)
FIVE: IF YOU DO IT NEW, DO IT WELL
SIX: RESPECT THE ECO-HOUSE NO-NOS
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Basic Design principles for different climates
HOT HUMID:
 MAIN CHARACTERISTICS:
 High humidity with a degree of "dry season".
 High temperatures year round.
 Minimum seasonal temperature variation.
 Lowest diurnal (day/night) temperature range.
KEY DESIGN PURPOSES:
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Employ lightweight (low mass) construction.
Maximize external wall areas (plans with one room depth are ideal) to
encourage movement of breezes through the building (cross ventilation).
Site for exposure to breezes and shading all year.
Shade whole building summer & winter (consider using a fly roof).
Use reflective insulation & vapour barriers.
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Ventilate roof spaces.
Use bulk insulation if mechanically cooling.
Choose light colored roof and wall materials.
Elevate building to permit airflow beneath floors.
Consider high or raked ceilings.
Provide screened, shaded outdoor living areas.
Consider creating sleep out spaces.
Design and build for cyclonic conditions.
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WARM HUMID CLIMATE
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MAIN CHARACTERISTICS:
High humidity with a definite "dry season".
Hot to very hot summers with mild winters
Distinct summer/winter seasons.
Moderate to low diurnal (day/night) temperature
range.
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KEY DESIGN PURPOSES:
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Use lightweight construction where diurnal (day/night) temperature range is
low and include thermal mass where diurnal range is significant.
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Maximize external wall areas (plans ideally one room deep) to encourage
movement of breezes through the building (cross ventilation).
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Site for exposure to breezes.
Shade whole building where possible in summer.
Allow passive solar access in winter months only.
Shade all east & west walls & glass year round.
Avoid auxiliary heating as it is unnecessary with good design.
Use reflective and bulk insulation (especially if the house is air-conditioned)
and vapor barriers.
Use Elevated construction with enclosed floor space, where exposed to breezes.
Choose light colored roof and wall materials
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Provide screened and shaded outdoor living.
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HOT DRY, WARM WINTER
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MAIN CHARACTERISTICS:
Distinct wet and dry seasons.
Low rainfall and low humidity.
No extreme cold but can be cool in winter.
Hot to very hot summers common.
Significant diurnal (day/night) range.
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KEY DESIGN PURPOSES:
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Use passive solar design with insulated thermal mass.
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Maximize cross ventilation.
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Consider convective (stack) ventilation, which vents rising hot air
while drawing in cooler air.
Site home for solar access and exposure to cooling breezes.
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Shade all east & west glass in summer.
Install reflective insulation to keep out heat in summer.
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Use bulk insulation in ceilings and walls.
Build screened, shaded summer outdoor living areas that allow winter17
HOT DRY, COLD WINTER (Hot Arid)
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MAIN CHARACTERISTICS:
Low humidity year round.
High diurnal (day/night) temperature range.
At least two (usually four) distinct seasons.
Low rainfall.
Very hot summers common.
Cold winters.
Hot, dry winds in summer.
Cool to cold dry winds in winter.
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KEY DESIGN PURPOSES
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Use passive solar principles with well insulated thermal mass.
Maximize night time cooling in summer.
Consider convective (stack) ventilation, which vents rising hot air while drawing in cooler
air.
Build more compact shaped buildings with good cross ventilation for summer.
Maximize solar access, exposure to cooling breezes or cool air drainage, and protection
from strong winter (cold) and summer (dusty) winds.
Shade all east & west glass in summer.
Provide shaded outdoor living areas.
Consider adjustable shading to control solar access.
Auxiliary heating may be required in extreme climates. Use renewable energy sources.
Use evaporative cooling if required.
Avoid air-conditioning.
Use reflective insulation for effective summer and winter application.
Use bulk insulation for ceilings, walls and exposed floors.
Use garden ponds and water features in shaded outdoor courtyards to provide evaporative
cooling.
Draught seal thoroughly. Use airlocks to entries.
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TEMPERATE (WARM TEMPERATE)
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MAIN CHARACTERISTICS:
Low diurnal (day/night) temperature range near coast
to high diurnal range inland.
Four distinct seasons. Summer and winter can
exceed human comfort range. Spring and autumn are
ideal for human comfort.
Mild to cool winters with low humidity.
Hot to very hot summers with moderate humidity.
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KEY DESIGN PURPOSES:
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Use passive solar principles.
High thermal mass solutions are recommended.
Use high insulation levels, especially to thermal mass.
Maximize north facing walls & glazing, especially in living areas with passive
solar access.
Minimize all east & west glazing. Use adjustable shading.
Use heavy drapes with sealed pelmets to insulate windows.
Minimize external wall areas (especially E & W).
Use cross ventilation & passive cooling in summer.
Encourage convective ventilation and heat circulation.
Site new homes for solar access, exposure to cooling breezes and protection
from cold winds.
Draught seal thoroughly and use entry airlocks
No auxiliary heating or cooling is required in these climates with good design
Use reflective insulation to keep out summer heat.
Use bulk insulation to keep heat in during winter. Bulk insulate walls, ceilings
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and exposed floors
COOL TEMPERATE
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MAIN CHARACTERISTICS:
Low humidity.
High diurnal range.
Four distinct seasons. Summer and winter exceed human
comfort range
Cold to very cold winters with majority of rainfall.
Hot dry summers.
Variable spring and autumn conditions.
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KEY DESIGN RESPONSE
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Use passive solar principles.
High thermal mass is strongly recommended.
Insulate thermal mass including slab edges.
Maximize north facing walls & glazing, especially in living areas with passive solar
access.
Minimize east & west glazing.
Use adjustable shading.
Minimize south facing glazing.
Use double glazing, insulating frames and/or heavy drapes with sealed pelmets to
insulate glass in winter.
Minimize external wall areas (especially E & W).
Use cross ventilation & night time cooling in summer.
Encourage convective ventilation & heat circulation.
Site new homes for solar access, exposure to cooling breezes and protection from cold
winds.
Draught seal thoroughly and provide airlocks to entries
Install auxiliary heating in extreme climates. Use renewable energy sources.
Use reflective insulation to keep out heat in summer.
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Use bulk insulation to keep heat in during winter. Bulk insulate walls, ceilings and
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The Built Environment as a Technological System (Pearce 1999, adapted from Yeang 1995, Roberts
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Building Structural/Construction Systems
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The combinations of materials used to build the main
elements of our homes: roof, walls and floor are referred to as
construction systems. They are many and varied and each has
advantages and disadvantages depending on climate, distance
from source of supply, budget and desired style and
appearance. The different building systems are:
The traditional kacha houses with walls of sun dried mud
( adobe) and wooden roof. Wooden frames provided as bonds
at different levels along the length of walls.
Bhonga houses with conical roof of inner dia 3 to 6 m with
adobe walls and bamboo framed roof covered with thatch.
The walls also having wooden frames.
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Single story brick/ Block masonry houses with
reinforced concrete roofs. Ext. Wall: 13.5 in , Int.
Walls: 9 in Block masonry: 8 in – Wooden roof
truss with CGI sheets or RCC 4 in thick slab.
Stone masonry walls and Wooden and CGI sheets
roofs. Stone masonry walls and RCC roofs
Reinforced Concrete Structures.
Frame structures with columns, beams and slab
connections.
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Conditions in selection of structural systems
1. Soil conditions
2. The program and concept
3. Applicable codes
4. Potential code changes
5. Flexibility
6. Impact on finished-ceiling and building height
7. Material delivery and construction timing
8. Local construction capabilities and preferences
9. Ease of construction and schedule
10. Cost of the selected system
11. Cost impact on other systems
12. Appearance and aesthetic potential
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Environmental Considerations in Selecting the Building
Structure System
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Make more efficient use of existing materials.
Minimize the amount of waste.
Use materials with least environmental impact.
Consider both operational and whole lifecycle performance of
materials and designs.
Use fully recycled materials or materials with recycled content.
Re-use whole buildings or parts thereof to reduce consumption
of new materials.
Choose materials with a lifespan equivalent to the projected life
of the building.
Design to extend building lifespan (current average 50 years aim for 100+).
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Design and build for de-construction, re-use, adaptation,
modification and recycling.
Encourage development of new, efficient, low impact
materials and applications by creating demand.
Consider how and where the materials are sourced and the
impacts this causes.
Minimize the energy used to transport materials by using
locally produced material. Use of lightweight material where
appropriate also reduces transportation energy.
Minimize the energy used to heat and cool the building by
using materials that effectively modify climate extremes.
Understand how chemicals used in the manufacture of some
materials might affect your health.
Minimize or eliminate emissions during use and manufacture.30
Mud brick (Adobe)
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The ideal building material would be
'borrowed' from the environment and
replaced after use. There would be little or
no processing of the raw material and all
the energy inputs would be directly, or
indirectly, from the sun. This ideal material
would also be cheap. Mud bricks come
close to this ideal, or they can do.
The appearance of mud bricks reflects the
material they are made from. They are thus
earthy, with color determined by color of
clays and sands in the mix. Finished walls
can express the brick patterns very strongly
at one extreme or be made into a smoothly
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Performance parameters of Mud
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Structural capability
With thick enough walls, mud brick can create load bearing structures up to
several stories high.
Thermal mass
Adobe walls can provide moderate to high thermal mass, but for most
climatic conditions, as a rule of thumb, walls should be a minimum of 300
mm ( 12in) thick to provide effective thermal mass.
Insulation
Contrary to popular belief mud bricks are not good insulators. Since they
are extremely dense they lack the ability to trap air within their structure.
Insulation can be added to adobe walls with linings.
Fire and vermin resistance
Since earth does not burn, and earth walls do not readily provide habitat
for vermin, mud brick walls generally have excellent fire and vermin 32
resistance.
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Durability and moisture resistance
Adobe walls are capable of providing structural support for centuries but they
need protection from extreme weather (eg. with deep eaves) or continuous
maintenance (the ancient structures of the Yemen have been repaired
continuously for the centuries they have been standing). As a general rule,
adobe needs protection from driving rain (although some adobe soils are very
resistant to weathering) and should not be exposed to continuous high moisture.
Breath-ability and toxicity
Mud bricks make 'breathable' walls but some mud brick recipes include
bitumen, which potentially results in some out gassing of hydrocarbons. Ideally
earth should be used in its natural state or as near it as can be achieved.
Sustainability (Environmental impacts)
Mud bricks have the potential to provide the lowest impact of all construction
materials. Adobe should not contain any organic matter
Build-ability, availability and cost
Mud bricks provide a forgiving construction medium well suited to ownerbuilder construction.
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Concrete slab floors
Concrete slab floors come in many forms and can
be used to provide great thermal comfort and
lifestyle advantages.
Benefits:
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Thermal Mass describes the potential of a material to
store and re-release thermal energy. Highest here
Durability is one of the other main advantages of
concrete slabs.
Termite resistance is achieved with concrete slabs by
designing and constructing them in accordance with the
code.
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Design parameters of Concrete slabs
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Passive solar design principles and high mass construction work
well together, and concrete slabs are generally the easiest way to
add thermal mass to a house .
Natural ventilation must be provided for in the design
Insulation of the slab edge is important in cooler climates, to
prevent warmth escaping through the edges of the slab
Balconies extended from the main slab of a house may act as
cooling or heating fins, carrying precious warmth away to the cold
exterior during winter, or transferring heat from summer sun inside .
Acoustics need to be considered.
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Clay brick
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Clay brickwork is made from selected clays that are molded
or cut into shape and fired in ovens.
The firing process transforms the clay into a building
component with high compressive strength and excellent
weathering qualities, attributes that have been exploited for
millennia to build structures ranging from single-storey
huts to enormous viaducts.
Clay brickwork is most widely used in external cladding
and load bearing wall medium and continues to enjoy rapid
growth in its use.
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Performance Summary
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Appearance
Clay brickwork is available in a great variety of natural colors and textures derived
from fired clay used in combination with cement mortar joints of various colors and
finishes.
Structural capability
The high compressive strength of fired clay bricks has been exploited for millennia to
build structures ranging from single-storey huts to massive public buildings and
enormous bridges and viaducts.
Thermal mass
Clay brickwork has high thermal mass.
Insulation
Clay brickwork, combined with internal and external air films and a cavity, has
moderate thermal resistance.
Sound insulation
Due to their mass, clay bricks provide excellent sound insulation, particularly for low
frequency noise.
Vermin resistance
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Clay brickwork consists of dense inorganic materials that do not harbour vermin.
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Sustainability (environmental impacts)
Clay brick manufacture uses energy but the investment of embodied
energy is repaid by the longevity of the material.
Clay brick homes have a long life and low maintenance costs
making them a potentially sustainable form of construction.
Option 1
: Brick veneer/timber frame/concrete slab
Option 2
Brick veneer/steel frame/concrete slab
Option 3
Double brick/concrete slab
Option 4
Timber clad/steel frame/concrete slab
Option 5
Timber clad/timber frame/concrete slab
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Lightweight timber
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Wooden structures have been used in all kinds of
building types for many years.
In a world living with the effects of global warming,
timber provides a renewable building material that
stores carbon in its production.
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Performance Summary
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Appearance
Aesthetically, timber possesses a natural attractiveness that people readily relate
to.
Structural capability
Timber has good compressive strength but is strongest in tension
Thermal mass
In general timber has low thermal mass
Insulation
Timber is a natural insulator due to air pockets within its cellular structure
Sound insulation
The sound insulation of walls is usually obtained by providing a barrier of
sufficient mass to absorb the sound energy.
Fire Resistance: very low
Durability and moisture resistance
Timber is an organic material and deteriorates due to weathering.
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Toxicity and breath ability: Timber is generally non-toxic.
Sustainability (environmental impacts)
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Timber is a renewable building resource that absorbs
carbon it its production.
A lightweight timber construction can be built for
deconstruction, and timbers from the construction reused or
recycled at the end of its use in the building.
It has tremendous capacity to provide a sustainable
construction option.
Timber is completely biodegradable and can even be
composted if no reuse application can be found.
Build ability, availability and cost
Lightweight timber construction is relatively simple to
build.
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Choice of Appropriate Building Materials
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The "appropriateness" of a building material or
construction technology can never be generalized.
The following questions show some of the main factors,
which determine appropriateness:
 Is the material produced locally, or is it partially or
entirely imported?
 Is it cheap, abundantly available, and/or easily
renewable?
 Has it been produced in a factory far away
(transportation costs!);
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Does it require special machines and equipment,
or can it be produced at lower cost on the building
site? (Good quality and durability are often more
important than low procurement costs).
 Does its production and use require a high-energy
input, and cause wastage and pollution? Is there an
acceptable alternative material, which eliminates
these problems?
 Is the material and construction technique
climatically acceptable?
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Does the material and construction technique provide
sufficient safety against common natural hazards (e.g. fire.
biological agents, heavy rain, hurricanes, earthquakes)?
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Can the material and technology be used and understood
by the local workers, or are special skills and experience
required?
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Are repairs and replacements possible with local means?
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Is the material socially acceptable? Is it considered low
standard, or does it offend religious belief? Does it match
with the materials and constructions of nearby buildings?
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Recorded Historical
Perspective
BACK GROUND
John Ruskin (1819-1900)
The Arts And Crafts Movements
(William Morris – 1834-1896)
Art Nouveau: 1890-1905
Victor Horta (1861-1947)
Frank Lloyd Wright (1867-1959)
Design For The Machine Age
(1900-1930)
De Stijl (1917 – 1931)
The Bauhaus (1919 – 1933)
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Eco Materials
Definition :Materials those have, the lowest
possible negative impact to the natural
environment, minimal net negative impact
to the natural environment, and maintain
some reasonable level of human
satisfaction in their technological and
socioeconomic performance could be
defined as "eco-materials".
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Eco Materials
 Assessment System
 Japanese Study
 Study By Technical Research Center Of
Finland
 Study By National Institute Of Building
Sciences (USA)
 Study By American Institute Of
Architect’s Environmental Resource
Guides
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GUIDELINE PRINCIPAL FOR MATERIALS
Avoid Ozone-depleting Chemicals In Mechanical
Equipment And Insulation.
Use Durable Products And Materials
Choose Low-maintenance Building Materials
Choose Building Materials With Low Embodied Energy.
Buy Locally Produced Building Materials
Use Building Products Made From Recycled Materials
Use Salvaged Building Materials When Possible.
Seek Responsible Wood Supplies.
Avoid Materials That Will Off gas Pollutants.
Minimize Use Of Pressure-treated Lumber.
Minimize Packaging Waste.
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Construction Material Used In Outer Walls
(Percentage) By Rural/Urban 1998
Construction Material
All Areas
All Categories
Baked
Bricks/Blocks/Stones
Unbaked Bricks/Mud
Wood/Bamboo
Others
1998
Rural
Urban
100
58.46
100
45.96
100
85.76
34.48
44.69
12.16
5.42
1.64
7.20
2.14
1.50
0.54
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CONSTRUCTION MATERIAL USED IN ROOFS
(PERCENTAGE) BY RURAL/URBAN 1998
Construction Material
All Areas
1998
Rural
Urban
All Categories
RCC/RBC
Cement/ Iron Sheet
100
21.39
13.07
100
10.43
10.05
100
46.35
19.69
Wood/Bamboo
Others
57.35
8.18
69.76
9.76
30.23
4.74
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Construction
Material Used In
Housing Units By Tenure
Owned
Rented
Housing Units
Rent-free
Total
Recent
Outer Walls
Baked Bricks / Block /
Stones
8,986,336
1,457,13
1
787,454
11,230,291
58.46
Unbaked Bricks / Earth
Bound
5,523,351
176,179
924,765
6,624,295
38.48
Wood / Bamboo
842,464
17,531
181,828
1,041,823
5.42
Others
245,104
8,414
61,181
314,699
1.64
Roof
RCC / RBC
2,933,671
859,521
317,074
4,110,266
21.39
Cement / Iron Sheets
2,012,871
341,804
157,075
2,511,750
13.07
Wood / Bamboo
9,334,805
397,011
1,285,785
11,017,601
57.35
Others
1,315,908
60,919
195,294
1,572,121
8.18
Total
15,597,25
5
1,659,25
5
1,955,228
19,211,738
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100.00
Pakistan – Rural
Outer Walls
Baked Bricks /
Block / Stones
5,470,9
56
205,316
381,85
1
6,058,12
3
45.96
Unbaked Bricks /
Earth Bound
4,967,6
80
74,485
848,50
8
5,890,67
3
44.96
Wood / Bamboo
777,800
8,701
162,92
8
949,429
7.20
Others
224,109
4,305
53,669
282,083
2.14
Roof
RCC / RBC
1,194,0
63
97,148
83,849
1,375,06
0
10.43
Cement / Iron
Sheets
1,210,9
88
38,844
74,363
1,324,19
5
10.05
Wood / Bamboo
7,933,3
80
139,263
1,121,
879
9,194,52
2
69.76
1,102,11
17,552
166,86
1,286,53
Others
53
9.76
PAKISTAN – URBAN
OUTER WALLS
3,515,380
1,251,8
15
405,603
5,1
72,
798
85.76
555,671
101,694
76,257
733
,62
2
12.16
Wood / Bamboo
64,664
8,830
18,900
92,
394
1.53
Others
20,995
4,109
7,512
32,
616
.54
Baked Bricks / Block /
Stones
Unbaked Bricks / Earth
Bound
Roof
RCC / RBC
1,739,608
762,373
233,225
2,735,206
45.35
801,883
302,960
82,712
1,187,555
19.69
1,401,425
257,748
163,906
1,823,079
30.23
Others
213,794
43,367
28,429
285,590
Total
4,156,71
1,366,4
508,272
6,031,430
Cement / Iron Sheets
Wood / Bamboo
54
4.47
100.0
GREEN WATERS HAVE NO WORRIES
55
BUT WIND GIVES THEM WRINKLES
56
BLUE HILLS ARE NOT SO OLD
57
BUT SNOW GIVES THEM WHITE HAIR
58