§ Introduction
§ Siting
§ Workers
§ Construction site
§ Construction yard for Production of houses
§ Design/ Layout
§ Process-based design
§ Work with local community
§ Desires of community primary
§ Overview of systems approach to design
§ General over-arching concerns
§ “Patterns” based on local culture (see A Pattern Language)
§ Utilizing assessment materials
§ Food, bathroom use, etc.
§ Be sure to talk to the women!
§ Circulation
§ Weather protection
§ Protection against natural disaster
§ Security
§ Affordability
§ Maintenance
§ Energy-efficiency
§ Passive solar
§ Basic ideas on how rooms can best go together for efficient planning
§ New buildings
§ Add-ons/repair of existing
§ Materials
§ Foundations Options and Drainage
§ Earthbags
§ Wall Systems
§ Straw bale Construction
§ Cob Construction
§ Adobe Construction
§ Others
§ Doors and Windows
§ Roofs, Ceilings and Insulation
§ Plasters and Finishes
§ Floors
§ Utilities
§ Landscaping
§ Tool and Material List
Introduction to Locally-Appropriate Building
What is “locally-appropriate?
§ Local materials
§ Native skills
§ Promotes cultural continuity
§ Sustainable
§ Based on principles of “natural building”
What is natural building?
§ “Any building system which places the highest value on social and environmental sustainability” Michael Smith
§ Minimizes ecological impact
§ Healthy, beautiful, comfortable, spiritually uplifting and inexpensive
§ Utilizes easy-to-learn techniques and locally available renewable resources
§ Human labor and creativity instead of capital, high technology and “experts”
§ Regionally appropriate
§ Depends on local ecology, geology and climate, building site, and needs and personalities of builders and users
§ Not a new idea – rediscovering ancient techniques and applying them to our modern living situations
Environmental Impact
§ Building industry is a major contributor to environmental problems
§ Deforestation, mining, greenhouse gases, energy and water use – all from building construction and use
§ Most natural building materials are biological by-products, or minimal impact mined minerals – these are low-embodied energy materials
§ Natural builders try to minimize and localize damage
§ Use of local natural materials reduces dependence on manufacturing and transport industries
§ Use of recycled materials to reduce pollution, turn waste into a resource.
Human Health
§ Modern buildings are making many people sick. Toxic materials in buildings that don’t “breathe”
§ Natural buildings are life enhancing
§ Modern buildings – artificial angles and colors – may be detrimental to psychological health
Social Justice
§ Modern building industry takes the power to build houses out of the hands of people
§ 1/3 of the world’s population is homeless or in substandard housing
§ Current building codes reduce options – leading to higher costs
§ We think we have to pay experts – architects and builders a lot of money for a big house
§ There is a great need for affordable housing
§ New options which utilize local materials and owner’s labor can bring down costs, especially in labor-rich countries
§ Natural builders advocate small houses which use passive-solar techniques for heating and cooling
§ A small low-cost house provides more time for family, friends and creativity
§ Natural building creates a different social dynamic than conventional construction
§ Whole family can get involved
§ Natural building worksites can be safe places for children
§ Building a natural building with friends builds community as well
§ Natural buildings reduce our impact on the environment – frees up resources for the less-privileged and future generations
§ One of the most critical design decisions
§ Difficult to correct a bad siting decision once building is built
§ Best to spend a lot of time on building site to determine weather patterns, special spots, sun patterns, etc. Ideally one full year to experience the seasons
§ Do research – speak to neighbors, consult historical records etc.
§ Slope – A sloped site can help drain water and air. Gravity can help with many common household needs (moving water, etc.) Excavation can provide building materials
§ Aspect – South facing slopes (northern hemisphere) are best for buildings (opposite in southern hemisphere)
§ Drainage – well-drained soils are best. Stay away from seasonal creeks and gullies
§ Subsurface geology – dig a lot of test holes to see what is there
§ Proximity to water (potable)
§ Proximity to growing areas
§ Potential
§ Do not build on good agricultural soils
§ Existing
§ Solar access – make sure sun can hit your building from the south (north in southern hemisphere)
§ Shade – shaded areas are best on southwest (northwest in southern hemisphere), west parts of site. Deciduous trees or vines shade in summer but let in light in winter
§ Prevailing winds – find out which directions storms and pleasant breezes come from (can be different in different parts of day/ year)
§ Air drainage – avoid low spots (frost hollows) where cold air collects
§ Fire – avoid ridges or hilltops
§ Floods – stay above “worst-case” flood zone
§ Master planning – how does your building fit into existing and future development
§ Access – how will you get yourself, materials to site
§ Water and utilities – determine how will you get them to site, how you will remove/treat wastes
§ Building materials – determine where they will come from. Consider using local materials as much as possible. Store near site, on “uphill” part if possible to make transport easier.
§ Zoning and regulations – find out land use near you, zoning restrictions. Develop good relations with neighbors
§ Privacy – visual, noise, smells, light
§ Security – from natural and social stresses
§ Community – isolated or near others
§ Easements – when someone else has permission to do something on your property
§ Future development – check with local planning department
§ Views
§ History – archeological, cultural, toxic uses in past
§ Ecological impact – determine the habitats of other species
§ Consider building on “worst” part of site (most disturbed/impacted) for ecosystem rehabilitation
§ Feng Shui/ Intuitive placement
§ Chinese art of placement (known as “geomancy” in the west)
§ Intuitive sense of what “feels” right
§ Don’t build on most “magic” spots
§ Staying put – consider staying where you are and improving where you already live
§ Renovation of existing structures
§ Often the most desired option
§ Commutes – sites with long transportation commutes will outweigh any energy savings in buildings
§ Available resources – are good building materials on site?
§ Remoteness – building in remote areas can disrupt wilderness and lead to further development
§ Size – determine smallest “destruction zone” you can manage
§ Rope off fragile areas during construction
§ A smaller house saves energy and resources too
§ Work with local community
§ Desires of community primary
§ Work with rough models, sketches, mockups
§ Reduce reliance on highly-detailed “plans”
§ These can be produced once good design is determined for reference
§ Consider all aspects at once
§ Planning thoroughly early on to avoid costly mistakes
§ Flexible design “philosophy” to fit local needs and conditions
§ Wise choices of materials and design to save energy
§ Good construction – so lasts as long as possible
§ Solves more than one problem at a time, does not create any new ones
§ Works well at all levels, not just a few
§ Creatively works with local skills and resources
§ Improves balance and harmony
§ Is flexible
§ Open to future renovation/ addition
§ Uses land appropriately, reduces destructive activities
§ Uses resources efficiently
§ Supports human health through choice of materials and methods
§ Strengthens the local economy and supports the community
§ Conserves the Biosphere
§ Protects agricultural sites, cultural resources, and archeological remains
§ Creates nice places to live
§ Creates buildings which are inexpensive to build and operate
§ “Patterns” based on local culture (see A Pattern Language)
§ Utilize assessment materials to determine
§ Work these out extensively with local people
§ Do not make assumptions
§ Food, sleeping, bathroom use, etc.
§ Be sure to talk to the women!
§ Circulation
§ Weather protection
§ Protection against natural disaster
§ Structural considerations
§ Security
§ Affordability
§ Maintenance
§ Energy-efficiency
§ Passive solar
§ Basic ideas on how rooms can best go together for efficient planning
§ Nice detailing
§ Integration of indoor and outdoor space
§ How done is dependent on climate
§ Examples: Hot/dry – courtyards
§ Hot/humid - verandas
§ Different strategies for each type
§ Residential
§ Commercial
§ Industrial
§ Transitional
§ Temporary
§ “Ecological design” is one such approach
§ Basic Ecological Principles
§ Systems
§ Flows and cycles
§ Waste equals food
§ Carrying capacity
§ Design Principles
§ Solutions grow from place
§ Ecological accounting informs design
§ Design with nature
§ Everyone is a designer
§ Make nature visible
§ Healthy for people and planet
§ Non-toxic materials
§ Less destructive to the ecosystem
§ Healthy indoor environment
§ “Restorative” design helps improve degraded ecosystems
§ Ecologically-designed homes ideally produce own energy and food, collect clean air and water
§ Solutions grow from place
§ More here
§ Ecological accounting informs design
§ More here
§ Design with nature
§ More here
§ Everyone is a designer
§ More here
§ Make nature visible
§ More here
§ Determine overall program
§ Identify cultural/spiritual components of design
§ Determine “program” (use assessment data)
§ Based primarily on desires of local people
§ Daily activities
§ Be sure to acknowledge desires for status, cleanliness, modernity, etc.
§ Creatively use local materials to satisfy these desires
§ Create sketches, model and/mockups, work on site as much as possible
§ Satisfy any code requirements – work with, not against code officials
§ Climate – determines shape of house
§ Hot/dry or cold – compact
§ Conserves energy
§ Hot/humid – more spread out
§ Allows for cooling breezes
§ Also determines foundation/wall/roof/finish choices
§ Main rooms to the south (north in southern hemisphere)
§ Small efficient plan
§ Simple layout for ease of construction
§ Design to the module of materials at hand
§ Building materials
§ Reduce, reuse, recycle
§ Designs which can be readapted easily
§ Import materials from closest source
§ Use materials low in embodied energy
§ Life cycle analysis
§ Pay attention to building site – reduce impact on animals and plants
§ Energy efficiency
§ Good insulation
§ Passive solar design
§ Good use of local energy resources
§ Wind, solar, hydro, etc.
§ Cooling – awnings, trellises, trees
§ Minimize west windows, create proper south overhang (north overhang in southern hemisphere)
§ Natural ventilation – cool towers, evaporative cooling, roof vents
§ Natural insulation – growing plants on outside of building
§ Use north side of building for cool storage
§ Thin buildings in hot humid climates for good cross-ventilation
§ Passive solar design
§ Place most of windows towards south (north in southern hemisphere)
§ Overhang blocks summer sun, lets in winter sun
§ Long thin house with big bank of south windows maximizes solar gain
§ Use thermal mass where sun hits to absorb and store heat (bricks, earth, adobe, etc.) Water stores heat too.
§ Attached greenhouse
§ Can add humidity to house
§ Trombe wall
§ Not so much of an issue in hot/humid climates
§ Additional Heat Sources
§ Efficient stoves/ovens
§ Provide proper combustion air/ venting
§ Radiant floor/wall heating
§ Fireplaces are not very efficient heaters but nice socially and experientially
§ Helps keep temperature in the house even
§ Most important in roofs, then walls and floor
§ Avoid large skylights – major heat gain in summer, heat loss in winter
§ Natural insulation – cellulose, wool, cotton, straw
§ Reflective foil for undersides of roofs, roofs can be painted white for added reflection
§ But be aware of glaring light for neighbors
§ Thatched roof are good insulators
§ Make north wall particularly well-insulated (south in southern hemisphere)
§ Seal windows, doors against drafts
§ Window insulators – double-glazed windows, insulated curtains on inside, shutters on outside
§ Make sure fireplace has a damper, combustion air comes from outside
§ Many modern materials give off toxic fumes
§ Sick building syndrome
§ Multiple chemical sensitivity
§ Use non-toxic building materials, paints, carpets, cleaning products, etc.
§ Metal in buildings – negative effects of electromagnetic waves
§ Make sure to ground metal in building to earth
§ Renovation
§ Temporary Structures
§ Local availability
§ Natural
§ Recycled
§ Locally manufactured
§ Strength
§ Durability
§ Properties
§ Tensile capacities, etc.
§ Aesthetics
§ Cultural value
§ Symbolic value
§ Ease of workmanship
§ What is “natural?”
§ One definition – that which is closest to the state found in nature
§ Non-harmful to humans and to the ecosystem
§ Natural builders use some “non-natural” materials with particularly useful or non-replicable properties as well (i.e. waterproof membranes, concrete in foundations)
§ Ecological impact
§ Availability
§ Workability
§ Embodied energy (energy needed to produce and transport a given amount of material)
§ Impact of harvest/extraction from ecosystem
§ Composed of stones, gravel, sand, silt, clay and organic material
§ Stones largest-sized component, clay the smallest
§ Best earth for building – 20-30% clay, 70-80% sand
§ Building techniques which use earth – rammed earth, adobe, cob, earthbags, pressed earth blocks
§ Used for thousands of years. At least 1/3 world’s population live in earth houses
§ Strong in compression, weak in tension
§ Needs special protection from water and earthquakes
§ Sedimentary, igneous or metamorphic
§ All earth materials were originally stone
§ Igneous stone
§ Formed by cooling of liquid magma
§ Some has air bubbles making it a good insulator (pumice)
§ Sedimentary stone
§ Sediments from erosion by wind or water cemented together by pressure and time
§ Layered – splits easily into flat pieces
§ Metamorphic stone
§ Igneous or sedimentary stone altered by heat, pressure or chemical weathering
§ Usually a good wall building material, splits easily into blocks
§ Best stone for building – angular with flat parallel sides
§ Stone makes excellent foundations
§ Thin flat stone can be used as a roofing material (slate)
§ Can be expensive and labor intensive to build with stone, but lasts a very long time
§ Is comprised of small stones
§ Useful for lining drainage trenches and for creating rubble-trench foundations
§ Can be used to fill bags for a “low-tech” foundation – keeps water from wicking
§ Is an essential ingredient of concrete
§ Can form an ingredient in cob
§ Is small gravel
§ Essential material for earthbuilding techniques (with clay) and concrete
§ Angular sand best, but this type is often created by destructive mining practices
§ Fine rounded sand good for finish plasters
§ Smallest soil particle
§ Weathered from the mineral feldspar
§ Is composed of flat plates that stick well to themselves and each other
§ Essential as a binder in earthbuilding
§ Does not react well with cement
§ To find – notice clumpy soils, or soil with a lot of cracks
§ Bricks are formed from clay on are then baked in a kiln
§ The higher the temperature they are baked, the harder they become
§ Bricks come in many shapes and sizes
§ Commonly used in walls but can also be used for floors or vaulted roofs
§ Flat thin element made from fired clay (curved tiles often used to form roof surfaces)
§ Used to create a hard, waterproof surface
§ They come in many different colors for decoration
§ Usually attached to a base material which is structurally strong (stone, concrete)
§ Used for floors, wall surfaces, counters and roofs
§ Tile roofs are excellent for catching rainwater
§ Is the interwoven roots of grass and the soil they capture
§ Can be cut into bricks and stacked like adobes
§ Placed on roofs to create a “living roof”
§ Comes from the harvesting of trees
§ Not all trees are good for building
§ Strong in compression, tension and bending
§ Lightweight, renewable, benign, flexible, forgiving, easy to build with
§ Little energy needed to process it and transport it
§ Can be used for posts, beams, floors, roofs, windows, doors, furniture and wall coverings
§ Must be used wisely to help decrease deforestation
§ Engineered timber created by gluing smaller pieces of wood together to form specially-shaped or sized members
§ Can be used to form walls – low insulation
§ Can also be used like bricks in cordwood construction
§ Logs “in the round” are stronger than milled lumber of the same cross-sectional size
§ I the thick layer of reeds, grass, straw or palm leaves used as a roofing material
§ Hollow stemmed water plants
§ Sheds water well, straight and long
§ Some reeds can be used to create structural roofs (vaults)
§ They are a lot of work to harvest, are of limited availability
§ Hollow stemmed stalk of cereal grains and grasses
§ Can be baled into large blocks and stacked to create walls
§ Used loose or fine as an additive to many earthbuilding mixtures
§ If long and strong can be used for thatch
§ Adds tensile strength, resistance to cracking, insulation value, increased workability of earthen materials
§ Not a natural material per the above definition but used by many natural builders
§ Made of sand, gravel, water lime and Portland cement
§ Pozzolans (rice hull ash, fly ash, brick dust) can be used to replace some cement in concrete (as well as cement plasters)
§ Mixed wet and poured into forms
§ The less water used, the stronger the concrete
§ Can also be sprayed dry and wetted at the nozzle to form walls etc. (gunnite)
§ Solidified and cures over time
§ Is kept wet while it cures for increased strength
§ Very high in compressive strength
§ Needs reinforcing to resist tension
§ Can be used in foundations, walls, roofs, etc.
§ However, very high in embodied energy
§ Difficult to recycle
§ If cut into uniform slabs can be cemented together like stone to form foundations/walls
§ Iron and carbon – harder and more flexible than iron
§ Used for metal roofs, reinforcing and structural members (not recommended for the “Faraday cage” electromagnetic effect which some believe can effect health)
§ High in embodied energy but easily recycled
§ Largest of the grasses
§ “Culms” (stalks) used in construction
§ Strong in tension and compression, weak in bending
§ Grows very quickly and can replace wood in many applications
§ Needs appropriate design details for long construction life
§ Most common in the tropics
§ Traditional binder made from limestone or seashells
§ Mixed with sand for plasters and mortar
§ Limestone is burned then crushed, then mixed with water (slaking) to make lime putty
§ Lime putty is best lime for building. Strongest in this form. Gets better stored over time.
§ Dried hydrated lime is much inferior
§ High embodied energy, but possibility for local manufacture
§ Softer and more flexible than cement
§ Breathes
§ Can be pulped and mixed with clay or cement to make blocks
§ Powdered paper makes good insulation
§ Used to make bags or for surface decoration
§ Reusing old doors, windows, etc.
§ “Trash” can be used in innovative ways, i.e. tires, bottles, cans, etc.
§ Entire buildings can be reused instead of torn down. Saves embodied energy of original manufacture
§ Cow manure best
§ Used to make fine plasters
§ Fresh manure can be used to create floors
§ Be careful in using fresh manure to avoid pathogens
§ Added to earth or lime mixtures to increase hardness, preservation, workability, or waterproofness
§ Includes: eggs, milk, blood, urine, oils, cactus juice, starch, tallow, sap, flour and molasses
§ Sticky test – rub paste between fingers. If it feels tacky it has clay. The tackier it is the more clay it has.
§ Ribbon test – make a rod the size of a pencil. Wrap it around your finger. The less it cracks, the more clay it has
§ Clumpy soil is usually clay
§ Soil with lots of cracks when dry is usually clay
§ Collect subsoil samples. Break up large clumps. Clumpy soils should be crushed to a powder
§ Place in a straight-sided clear jar
§ Add water and a pinch of salt to help clay settle
§ Shake jar
§ Wait a few minutes, then shake jar again
§ First five seconds of settling – all sand and gravel will have settled out. Mark side of jar at this point
§ Five seconds – ten minutes – all sand and silt will have settled. Mark the jar at this new layer.
§ If water is clear at this point there is no clay
§ When all is settled mark the final clay layer and determine proportions.
§ It is important to mark the layers as they settle as it is sometimes difficult to distinguish between the silt and clay layers
Drop test (for cob)
§ Shape your proposed building mixture into a small ball.
§ Throw the ball in the air and catch it in your hand
§ If it flattens there is too much clay or water
§ If it cracks apart there is too much sand or not enough water
§ If it keeps its shape it is good to build with
Crunch test (for cob)
§ Hold mixture to your ear and squeeze it
§ You will hear a “crunching” sound from the sand grains moving against each other which indicates that you have enough sand in the mix
FOUNDATIONS AND DRAINAGE
Purpose of foundation
§ Spreads load
§ Holds building together as one unit
§ Raises wall above water
Foundation choice determined by
§ Site considerations
§ Soil characteristics
§ Seismic considerations
§ Building type
§ Load type (point or evenly distributed)
§ Frost line
§ Money vs. labor
Foundation marked with stakes for round buildings or “batter boards” and string for rectilinear structures
If building with concrete forms are needed (usually wood)
§&nbs