Building Green

Building Green Or the Art of Building in a responsible manner

Michel L.Roger

SAEP 2009

Introduction

This short lecture is an opening to your awareness that we are all responsible of our future and how you and your children will have to face in regards with the climate change and the evolution of our economy. It is a document that should interest not only those of you who are thinking of taking the direction of studying Engineering, Technology or Architecture, but for all those who feel or think that a responsible approach to the environmental issues everyone of us has to consider is the only logical and reasonable one. This lecture will introduce you to the notion of Energy Crisis, Global Warming, Pollution and Ecology. I sub-titled this lecture on Architecture and Technology “The Art of building in a responsible manner”. Building an Eco-friendly place or a Green Home is about imagining and designing a home that saves energy, preserves natural resources and protect our environment. First of all, I am quite sure that you and I, are not a lottery winner and if not you, but your parents and guardians have strong concerns about saving their hardly won money, mainly reducing costs and budgets, in maintaining a home, transport, food and energy. Two, you may be well aware of the challenges humanity is facing today for the future of our planet and the people who will live on it in the very near future. Every one of us is now truly concerned. I introduced the word, but do you know something about global warming, air and water pollution, energy crisis and sustainability? In fact I did not know more than you and it is now clear on my mind that, as an Architect and TownPlaner, I had a real responsibility in tackling this question and find answers, because my profession was first on the line of fire! The majority of modern day buildings are still wasting energy, water and an enormous amount of natural resources. It was not our fault, nothing was taught at University. We were using fancy building materials and technologies that increased our requirements for more energy (lighting, airconditioning for warming and cooling, expensive finishes requiring more and more dependence upon raw materials). Most architects and engineers were completely unaware of the impact that buildings might have on people’s health and the environment. Following warnings send out by the United Nations and the scientific bodies, international conferences and national changes of attitude, our vision has shifted to a world where Economy and Ecology become inseparable.

Global Warming is the slow warming of the Earth, caused by a build-up of air pollution in the atmosphere which traps heat from the sun.

The impacts of global warming are severe. Changing water’s salinity will cause in a few decades rising sea level, forcing people living on low level islands like the Pacific or the Seychelles, deltas (in Bangladesh) to leave their homes and take refuge on higher grounds. Actually governments are taking measures to create barriers against rising waters. We will also experiment stronger hurricanes and floods (like in Mississippi and Louisiana); see more severe droughts, intense heat-waves and mass famines. A few degrees increases the risk of ice melting (glaciers in Europe and India) or loss of most of the ice of the Antarctica, which is now allowing ships on the North route, reducing tremendously their voyage. Each rand or dollar saved off the house energy bill is a step towards slowing down the effects of global warming. Today, we are seriously thinking of preserving and saving our diminishing resources. Eco-friendly or Green buildings became obvious to many architects all over the world. It is a way of looking at buildings that allows people to be more responsible with energy and their natural resources. Many of the “innovative”, green techniques we marvel today are ancient methods of building! Moreover, if one looks at the state of the world economy, one is certain that it is in the field of Ecology, Eco-building and Energy that millions of jobs will be created. A quick look at our history: The first sign of Green Building’s concept dates from the 1st century, nearly 1000 years ago, in Colorado and Arizona! Indian tribes who lived there, only used natural stones, mud and wood. They oriented their buildings to the light and were cooled and heated without any need for added heat or air conditioning. Fresh air, passive solar orientation, passive cooling has been used for and from more than thousand years.. We know that human activity is consuming a staggering amount of energy and non renewable resources. Building is the largest consumer of energy and resources. One should consider that building activity alone consume 40% of the world’s energy, 25% of the world’s wood harvest and 16% of all its water.

A “Green building” 1-provides healthier and more comfortable environment 2-reduces construction and demolition wastes 3-incorporates energy-water efficient technology 4-includes renewable energy technology 5-is easier to maintain and last longer All these factors can and will save money in construction and maintenance as well as operating your home. One example: It is quite clear that installing a solar panel costs, but you have to take in account that it produces its own electricity, immediately and you can eliminate your monthly electric bill on the very short term. Moreover, governments are offering you tax cuts and credits for any installation that reduces energy spending.

1- Steps to a Green Building 1- Building a new home or remodelling your existing home 2- Plan your financing (cost estimate and budget) 3- Choose a site, encourage in-fill location, minimize use of a car, preserve open spaces and existing trees. 4- Research the Planning Code requirements for heights limits, setback, allowable size building area 5- Diagram the site for sunlight, views and features (traffic, schools, amenities and new developments 6- Research for grants and incentives for green buildings 7- Create the preliminary design (your own needs and wishes, your finances and perspectives) 8- Set priorities for the materials to use 9- Dimension the building to match the unit of construction (see §n°7) 10- Choose a structural system based on local resources 11- Design the roof to allow solar panels, passive heating and cooling, green roof, insulating system and obtain all required permits and approvals.

2 - Designing a Green House The way to design a better and greener house is to follow the rules that are listed below. 1- Go for a smaller home, a larger than necessary mean a waste of space, an expansive maintenance (cooling and heating). 2- Create a multi-purpose space (the home office that could be used as a guest room when necessary) 3- Consider building more floors instead of a single-storey because it saves on construction costs and reduces the impact on the landscape too. 4- Select recycled materials 5- Minimize waste (design your bath-room using standard sized tiles) 6- Consider a” grey-water” system. You can save the soapy water that has been used in the kitchen and bath-room, dish-washing and clothwashing to re-use it later for flushing toilets or irrigating the garden. 7- Use rain water and collect it for garden and flush toilet.

3 - Building Green: An idea whose time has come. In the last hundred years, the Environmental devastation from our way of life has been enormous. Due to human industrial revolution, we have lost 50% of our wetlands, 50% of our forests and 70% of our marine fisheries. The impact is severe and getting worse. Our life support is dependant of the balance, by cleaning air, water and providing food. Building alone consumes 45% of the world’s energy and by 2050 the resources of our planet will not be able to support all our needs - China, India and developed Asia are increasing their needs in food and energy. More than any other industry, buildings are responsible for most of the damage done to the environment. Anyone building or remodelling a home is in a position to effect great change on the planet! In 1994, the United Nations came up with their definition of sustainability – meeting the needs of the present without sacrificing the needs of the future. People everywhere have been consuming if there is no tomorrow and with no or very little regards for the barren world that your children and grand-children will inherit. Ecology? Economy? The prefix ECO comes from the ancient Greek “oikos” translated into “house”. In Environmentalism the big house is the Planet Earth and it’s the only house we have! The suffix”nomy” means management and”logy” means knowledge. So Economy simply means House Management and Ecology means House Knowledge.

4 -The main Construction and Building materials 1) Exterior ° Siding: -Wall sidings are generally using aluminium, wood, fibrocement and stucco. Stucco is a mixture of Portland cement based product, normally applied or sprayed by hand. It can be painted over brick or concrete walls. ° Roofing - Asphalt shingles (sheets of asphalt) that represent 11’000 tons of asphalt roofing waste generated in the US only. Its dark colour absorbs the heat in summer, heating up your home unnecessarily! - Spray-on foam roofing (poly-iso) is a perfect choice for flat roofs. Once dry, it never leak and its yellow colour will deflect heat, cooling your house. You live in a generally hot country, so you should select the lightest colours available. A dark roof, like black cars, absorbs heat. - Use “rain-chain” for roofs to collect rain water in pipes or drums. - Set some sorts of water-catchments to conserve water and re-use for gardening and washing. Steel framing: It is a good insulator. Steel conducts heat and cold, ten times more than standard wood and it is fire resistant. Straw-bales: Thick walls of straw-bale have become synonymous with”green building”. It is considered a low-tech building technique, a clever use of waste material and a very attractive alternative to wood framing. 200 million tons of straw are wasted each year in the US only. The annual harvest could build 4 million homes every year. Straw-bale construction offers a high insulation value but can be costlier and difficult to work with. It is a good fire-resistant material. Bales are stacked like bricks and covered wit a lime plaster finish (usually a lime-based stucco). To fix the lime, chicken wire is wrapped over the straw. A straw-bale house has an insulation value 3 times that of a wood-framed one. The cost? It is nearly free! You do farmers a favour by taking away his bales, taking the waste off his hands. Straw-bale construction is a very simple system and home-owners could build their house themselves. You can also reduce the cost of cooling and heating installation, saving money from the start. It is quiet: The house is very silent and perfect for hot or cold climate but humid and damp regions are not the best climate for straw-bale. Tips: Use overhangs to keep the walls dry and push rain-water away. Design your house according to the dimensions of bales (40cm width x 60cm height x 1.00 m long).

Adobe Adobe is the original solar-powered building material. It consists of sun-dried bricks of mud and straw. It is probably the oldest building material, dating back thousand of years, until 2.000 BC. This material was used in Northern Africa, the Middle East and Ancient Egypt. The indigenous people of Central America used it for centuries. It is a low skill method of forming and stocking mud bricks. They are heatabsorbant, perfect for hot and dry climate. Adobe construction could last for hundred years. It will be necessary to talk to the Permit Administration Office before planning an adobe house. How it is made? A careful mixture of mud, clay, straw and water is poured into a wooden-frame and left to bake under the sun. The moulds are quickly removed and the bricks are dry in a matter of hours. A cement mortar is used to hold the bricks together. Adobe is a tremendous material in saving and it only requires a manual labour. No other energy is needed. Adobe has a wonderful high thermal mass. It stores up the heat from the sun all day and releases it at night when it’s cooler. It has no insulation value but keep your house comfortable all year round. It cuts your energy bill. Building several floors is not possible. An adobe house is typically a one storey high. Due to their thickness (30cm or 40cm thick) adobe is mainly used for external walls. Making same dimensions for windows will save labour and cost. Rammed-earth It is a mixture of clay and sand. The Pharaohs of High Egypt have built cities with this building material, formed in few minutes through compacting dirt. The construction system is similar to concrete building wit formwork sides, vertical and horizontal timber boarding creating a massive wall. Rammed-earth is nearly as strong as concrete but a structural engineer should be necessary to help and give you the correct mix and balance. The high thermal mass of rammed-earth can reduce your energy bill by 80% compared to a wood-framed house. However, it as no insulation value, so it has to be sprayed outside, like adobe. It is fire-proof and rot resistant. It is incredibly strong and can be used for every region, damp or hot areas. It is an excellent alternative to adobe for wet climates. It is mainly used for one storey building. Pneumatically Impacted Stabilized Earth (Pisé) This method of building creates a beautiful wall made of natural and healthy materials. It is a mixture of mud and cement packed into a form. It is a much shorter construction process.

Ceramic earth This method of construction was developed in Iran. It is made out the local earth. A large fire is burned inside the house to bake the walls, like ceramics. Te walls become completely water-proofs and earth-quake resistant.

5 – Energy Systems 40% of the entire world’s energy goes into the operations of homes, offices and factories. We are all dependants of the energy burning natural resources, particularly oil and coal. The current sources of energy: 1) - Oil: Consumption of oil increases continuously while supplies are rapidly running out. Pollution from cars and trucks creates the global warming effect as 1/3 of greenhouse gas emissions are from gas burned by automobiles. 2) - Natural gas: fossil fuel found in underground deposits (open air mines included) created millions of years ago cannot be re-created. 3) - Coal is a fossil fuel and cannot be produced again. The percentage of sources of energy, their use and availability is indicated below. Oil Natural gas Coal Nuclear Propane gas Bio mass Hydropower Geothermal Wind Solar

38% 23% 23% 8% 1, 7% 2, 9% 2, 7% 0, 3% 0, 1% 0, 1%

non renewable “ “ “ “ “ “ “ “ renewable renewable renewable renewable renewable

Transport and Manufacture Heating and Electricity Electricity Electricity Heating Heating, Electricity and Transport Electricity Heating, Electricity Electricity Electricity, Lighting and Heating

6 – Renewable Energy Systems 1) – Solar power (photovoltaic cells) When sunlight strikes the thin panel of silicon, the electrons get excited and start moving which produces an electric current. During the day, the panels produce energy and excess electricity is pumped back into the local electricity grid. Net result on electricity bill = 0. Excess electricity can be sold too. A 5kw energy system requires 500 sqf of roof space (4,5sqm). The number of solar panels to be used depends of the amount of power needed for the house. 2) – Wind-power The energy is provided by wind turbines and do not give gas emissions or air pollution. The early wind turbines were used in South Africa and in the US by farmers to pump water from wells and in Europe to grind wheat for bread (windmills) or to make weapons and tools. Fields of wind turbines are actually producing electricity in Germany, Holland, Sweden and the US, mostly near the coast or in the sea. One turbine produces enough electricity for 400 houses and a simple personal wind turbines cost around 3’000$ for 1kw (20’000 rand). 3) - Hydrogen Fuel cells Hydrogen cells are a device that converts the chemical energy stored in oxygen and hydrogen into electrical energy. The only thing it gives off is the combination of the two elements or H2O (water). One Hydrogen fuel cell in your basement could produce energy and drinking water for everyone in the building. It is a new technology and not widely available. This technology will probably be developed by 2020. Introducing Energy efficiency: Two main elements are to be looked at: - Insulation and Lighting. a) Skylights: They eliminate the need for electric lighting during the day. Install skylight away from direct sunlight (South facing in S.A) and choose operable panels to capture passing breezes. b) Sun tunnels or windows: Between 10 to 25% of your heating or cooling are leaking out your windows and un-insulated frames. Consider installing double-panel windows as a good way for savings. Prefer over-hangs to protect for sun-light.

Materials commonly used for window-frames: a) b) c) d)

Fibber-glass: best energy efficiency and look for recycled content frames Wood: energy efficient and need to be painted. It is renewable material except exotic qualities in danger of extinction. Vinyl: environmentally a dangerous material. Metal: poor energy savings and cold or eat conductor.

Note: Insulating value is calculated according to the material rating and the smaller number the better it is. U value
c) Thermal Mass: Insulation is the ability of a material to hold in temperature. Thermal mass is the ability to absorb and store temperature. Example: The sun heats up water during the day, the water stores up that heat. At night, when temperature outside decreases, the water releases this heat. This is thermal mass in action. This is how oceans and seas behave. Example: A concrete building in hot weather won’t work. It will never have a chance to release the heat. The building will even be hotter inside the satured thermal mass because there must be a change of temperature between day and night. d) Passive cooling: Trough the physical convection, heat rises. Warm air is lighter than cool air (see balloons)- When hot air rises, cooler air rushes in to take its place- Passive cooling uses this principle to create natural ventilation (see Iran, Yemen). A tall, open stairway can function as a thermal chimney. It is best to install skylights operable to let hot air to escape. e) Passive solar: Passive solar system design is working in most climates. Overhangs shade the building and allow winter sun to get in. House cooling is even best with trombe-walls or verandas. e) Heat islands: On warm days (thanks to the loss of green areas!), the temperature in urban areas can rise by more than 3°C. These heat islands increase the need of A/C. To reduce this need for cooling buildings one should consider the following principles: Dark surfaces absorb heat. Dark roofs increase the cooling load of a building and could reach 90°C. Choose a light coloured roof. A planted green roof is an excellent type of cool roof. Parking lots, tarred or paved, are notorious sources of heat islands. Use porous pavers where grass could grow through.

7 – Green landscaping and Site Planning The place where you plan to build your house is as important as the house itself. A good site is both a technical skill and an art.

A site analysis consists of taking a drawing of your property, then you locate the good things (amenities) and the bad ones (irritants). This exercise helps you figure out how to orient the house and where to locate the rooms. A typical site analysis includes: - Attractive views to maximize - Un-attractive views to minimize or views to block privacy - Noises to block (street, shops…) - Wind to allow air for cooling - Placement of activities (bedroom, dining, outdoor...) - Path of the sun And more important: what local materials are usable near the site. If possible, try to locate the house on a ”brown field” (cleaning a polluted site is better than a perfectly clean because subsidies could come from government).Your site analysis should consider public transports, schools and shopping facilities. You will look at location of water lines, gas and electrical lines, waste… Outdoor material: asphalt is the most common material used for parking lots and open spaces, private lanes and access ramps, playgrounds, but it poses few serious problems. Asphalt should be avoided at all cost. It is a mixture of petroleum and bitumen, product of crude oil. It is not renewable, it releases heat and increases temperature (+3°c). When rain-water hits the asphalt, toxic materials soak in the water, polluting it and run into water catchments, sewages