EcoSwitch

The Iconic Architecture EcoPimp Manifesto [Introduction]

egg11

ARCHITECTURE

Browsing through the blogosphere in search for modern architecture it seems like recent years ‘major league’ architecture has been one big party of more or less complex 3D software generated shapes. Looking at these architectural icons it feels like it is safe to say that contemporary, ‘top shelf’ architecture more and more slides towards being part of Show business.
Form does not follow function, it follows whatever the architect thinks looks cool when cutting blue foam for models or is playing with his or hers 3d software. After that the function is squeezed in to fit the design and then the whole is often edited to make it look like it was the other way around. This process is nothing to be ashamed of since that is just how show business works; you get a cool idea and then you make it work and in some cases that cool idea after some refinement even turns out to be intelligent. The problem is when architects deny that they are part of show business and hopelessly tries to intellectualize their design to make it look more scientific, intellectual or in other words more ‘architectonically correct’ and therefore accepted or even hailed by the design community. If we instead accept that iconic architecture by nature is quite non-intellectual a whole new set of horizons for iconic architecture can unfold.

As already mentioned, the easiest way to accomplish iconic architecture is to buy a 3d software and then make a complex and often highly expensive shape. The problem is that every architect regarding themselves to be class A material has by now used one of these programs to either design a hovering building, a blob or a stealthy looking thing, meaning that the effect of the 3d generated design is not as entertaining as it was 15 years ago. And another factor that speaks against this sort of architecture is of course that a huge amount of teenagers can download this type software for free and then make the same design as star architects on cheap desktops. Which is lovely but perhaps slightly embarrassing for some architects and perhaps a bit similar to the my-three-year-old-could-have-painted-this kind of comment in the abstract art museum. So if CCTV (The Chinese television HQ in Beijing, not Closed Circuit TV surveillance systems) does not get burned up I think the 3d generated iconic designs has reached its climax as an entertaining form of architecture and we can all start to move forward in search for a newer approach.

With the now all too familiar financial crisis scenario and the threat of global warming the natural continuation would perhaps be a more down to earth, cost efficient and sustainable approach to architecture. But, since contemporary architecture is a part of show business it is necessary to find a new approach that is cost efficient in a non-boring way. So, in the EcoPimp Manifesto Part Two, let me introduce you to the lovely world of architectural pimping and its potential.

Anders Berensson is the co-founder of the Swedish architecture studio Vision Division.

Visit Vision Division’s website here.

Posted under Eco Build

This post was written by Anders Berensson on March 17, 2009

-->

Notes From a Cold Island

window

UNITED KINGDOM

Question: How could uninsulated and drafty brick buildings be perpetuated and made into a national style to make the British housing stock among the worst insulated in the developed world? Indeed, this is the source of some amazement as the British isles are not famed for incessant sunlight and dry winters. Scandinavians know winters are cold. In Poland houses keep the heat inside. To cut a long story short, a majority of buildings in the UK are simply not meeting the basic requirements that most countries in a similar situation actually do. This reflects on both economy and ecology on the level of the individual home. Sharp rises in energy prices have forced people to think hard about how to make some savings. The average heating bill is now £600. Granted, a row of Terraced houses is in a way the epitome of Agatha-Christie-reading-tea-and-biscuit cosiness. But one of these properties also represents around 3 metric tonnes of CO2-emissions each year, only in heating.

With all the talk of Green New Deals and financial bail-out plans containing billions ear-marked for green investment all around the world, we seem to have a case for the kind of rebooting of the housing sector that is required. Shrinking domestic heating bills is arguably one of the best ways to reduce carbon footprints and spending the fiscal stimulus on this is, at least on paper, a win-win situation. Bringing a country’s housing stock up to 21st-century standards is a hugely expensive task. And for a nation of romantic cottages, this overhaul would involve major changes to the way houses look. An early victim, single-glazed sash windows with wooden frames might be a thing of the past. Or will they? The intricacies of cost-benefit logics may play tricks on us yet. (Note: A personal nemesis of mine, all but one of the leaking sash-windows in our house has been resolutely boarded up this winter.)

Chris Goodall is a climate change columnist in the Guardian, blogger at Carbon Commentary and the author of Ten Technologies to Save the Planet. From his column this Monday:

The UK needs an urgent, nationwide programme to drive down the costs and improve the standards of eco-refurbishments. The plan should be organised and run locally, with campaigns moving from street to street. As in Germany, state-owned banks should offer cheap and accessible finance for home improvements at interest rates close to zero. The banks may also need an element of outright compulsion. If householders have gone for several decades without insulating their cavity walls, even a 144-page government green paper isn’t going to persuade them to take action now.*

In the column from which the above paragraph is taken, Godall presents some of his own estimates of the cost of heat losses from a typical house, listing the source of heat loss and the yearly cost:

Walls £264
Windows £132
Ventilation £132
Roof £46
Floor £53
Doors £33

Godall goes on to say that even if draught and heat loss through windows and doors is ‘a good idea, the savings are relatively small and will be expensive to achieve. Buying double glazing might cost £5,000 for a house, while two external doors with really good insulation could set you back £500.’

So what will make the equation home+finance/home+environment work? A house might cut its gas bill by a third by doing one thing: insulate. Or rather make that two things: Loft and cavity wall insulation. This is a relatively high impact, low cost approach and a large detached property could, according to Godall, ‘potentially [be] recouping the cost in a year.’ Of course, this is because of the extreme expenditure would be cut down to only extraordinary.

What might be really troublesome on the other hand, once the funding and the will to get to the root of the problem have been mustered, there are the issues of heritage and aesthetics. Or perhaps the issue, Britain has a large conservationist grass-root movement that is drunk on post-card imagery and nostalgia. Godall, one last time:

The UK has large numbers of extremely poorly insulated older houses with solid walls, and the best way of insulating these properties may be to clad the external wall with a plastic cover which is then be rendered or painted. As well as being costly, this alters the external appearance of the house, and there would be enormous resistance to making our appallingly leaky Victorian brick houses look like modern Dutch apartment blocks. Unfortunately, a real war on carbon emissions requires us to make unpopular choices like this.*

* Article ‘Deep domestic cuts are needed to bring our housing footprint down’ by Chris Godall in The Guardian on the 9th of March 2009, read it here.

Posted under Climate, Eco Build, Environmental News, House & Home

This post was written by Leif Ahnland on March 11, 2009

-->

Ecobuild & Futurebuild 2009 Edition Opens Tomorrow in London [updated]

UNITED KINGDOM

Between Tuesday the 3rd and Thursday the 5th of March, Earl’s court in London will be host to what has become one of the most important arenas for the section of the building trade that aims for a better future. In September 2004, a small ‘green building’ conference alongside another event grew into Ecobuild. The fifth edition will attract more than 30,000 visitors who are offered more than 100 seminar and conference sessions. It has developed a strong following, amongst pioneering architects and designers as well becoming the hub of a community of suppliers of innovative sustainable construction products. The organisers claim it to be ‘the biggest and best showcase of sustainable construction products anywhere.’ On top of that, more than 100 free conference and seminar sessions makes for a healthy discussion where the public, professionals, academics and officials meet around what is arguably one of the single-most important sector’s of human activity when it comes to our environmental impact.

Ecobuild 2009 will take place against a backdrop of defeatism, and a construction industry in shambles will try hard to have anything upbeat to put on display. Paul King, Chief Executive of the UK Green Building Council answers that this way.

Even in tough times -and perhaps particularly in tough times- customers will demand more in terms of efficiency, quality and productivity. A built environment that is sustainable -economically, socially and environmentally- is the only one worth investing in now.

It goes without saying. But it seems, as things stand, that it needs to be repeated over and over again. The dissemination of information can in itself be an eco-activity and events like Ecobuild are helpful in that they provide arenas for the public, authorities and business to meet and learn. And pick up some promotional pens and key-rings. And eat candy. Nonetheless, chances are that visitors will leave the fair richer not only in logotyped gifts but in both knowledge and optimism as well. The built environment and housing is under fire, more or less correctly if a bit simplified, for being a major culprit in our deep carbon footprint but also for having plunged the world into recession -with housing speculation and sub prime mortgages triggering the financial nightmare. Therefore, seeing the developments of a building industry that aims for a lower impact will probably be a source of hope.

Visiting Ecobuild and all its attractions, seminars and conference sessions and most related events, is free of charge. With over 800 exhibitors showcasing everything from building structures to SUDS, micro-renewables to natural materials, and insulation to living roofs, there is going to be a lot to do. For example, last years introduction of ZAPfactory’s Zero carbon house* -which was built on site at the fair– will be followed up with another crowd-pleasing display. The most popular new initiative in 2008 was the Arena. This year it promises to be even more inspiring and entertaining; an eclectic mix of debates, interviews and keynotes that view the built environment from a series of different perspectives – politics, art, science, philosophy and more.

Three members of the EcoSwitch team are going to assist what is claimed to be ‘the world’s largest event dedicated to sustainable design, construction and the built environment.’

For more information on Ecobuild 2009, click here for the official website.

* Read more on ZAPfactory here.

Posted under Eco Build, Environmental News, Events

This post was written by Leif Ahnland on March 2, 2009

-->

Ecobuild 2009 Teaser

ecobuild

UNITED KINGDOMA month from now, on the 3rd of March, ‘the world’s biggest event dedicated to sustainable design, construction and the built environment’ opens in Earls Court, London. Ecobuild 2009 will take place against a backdrop of defeatism, and a construction industry in shambles will try hard to have anything upbeat to put on display. Paul King, Chief Executive of the UK Green Building Council answers that this way.

It goes without saying. But it seems, as things stand, that it needs to be repeated over and over again. The dissemination of information can in itself be an eco-activity and events like Ecobuild are helpful in that they provide arenas for the public, authorities and business to meet and learn. And pick up some promotional pens and key-rings. And eat candy. Nonetheless, chances are that visitors will leave the fair richer not only in logotype gifts but in both knowledge and optimism as well. The built environment and housing is under fire, more or less correctly if a bit simplified, for being a major culprit in our deep carbon footprint but also for having plunged the world into recession -with housing speculation and sub prime mortgages triggering the financial nightmare. Therefore, seeing the developments of a building industry that aims for a lower impact will probably be a source of hope.

Visiting Ecobuild and all its attractions, seminars and conference sessions and most related events, is free of charge. With over 800 exhibitors showcasing everything from building structures to SUDS, micro-renewables to natural materials, and insulation to living roofs, there is going to be a lot to do. For example, last years introduction of ZAP factory’s Zero carbon house* -which was built on site at the fair– will be followed up with another crowd-pleasing display. The most popular new initiative in 2008 was the Arena. This year it promises to be even more inspiring and entertaining; an eclectic mix of debates, interviews and keynotes that view the built environment from a series of different perspectives – politics, art, science, philosophy and more.

In September 2004, a small ‘green building’ conference alongside another event grew into Ecobuild. The fifth edition will attract more than 30,000 visitors who are offered more than 100 seminar and conference sessions. It has developed a strong following, amongst pioneering architects and designers as well becoming the hub of a community of suppliers of innovative sustainable construction products.

For more information on Ecobuild 2009, click here for the official website.

* Read more on ZAP factory here.

nland

Posted under Building Services & Suppliers, Environmental News, House & Home

This post was written by Leif Ahnland on February 4, 2009

-->

Urban Re:Vision Wants to Change the World – Design a Better Dallas

revision_dallas_headerblock

OPEN DESIGN COMPETITION LAUNCHED

Among other things, Urban Re: Vision organises competitions to find answers to pressing problems in the urban habitat. The intention with Re:Vision Dallas is ambitious to say the least -to make a serious case for a remake of the heartland of unsustainability and, more importantly, show how it can be done. The slogan goes ‘The future of cities starts now… one block at a time. It is a good slogan. Only there are so many blocks to do… Here is what Re: Vision is trying to do, a mission statement if you will:

Re:Vision is a revolutionary initiative to create the prototype for an innovative, sustainable urban community. At the heart of the process is a series of contests generating visionary ideas for what can and should be in the design about urban space.*

As far as competition can be revolutionary, they are dependent on how far the implementation goes. From the Re:Vision Dallas website, some tentative questions about what it could generate:

Our 6th competition in a series, Re:Vision DALLAS is an opportunity to create new site-specific designs that will transform an existing city block in Dallas into a model of sustainable practices. How will it change the landscape of the city, the region, and other urban settings around the country or the world? We invite you to be part of this ground-breaking effort and help lay the foundation for sustainable urban design.**

Architecture for Humanity’s founder Caeron Sinclair will be one of the competition judges. This in itself is a reassuring fact; Sinclair could function as a template for passionate integrity. His initiative, Open Architecture Network, is hosting another competion on the subject, the classroom of tomorrow [read about it here].

In December I wrote an article on a Texan utilities company’s approach to greenwashing under the heading Texas USA… What Shall We Do With It? [Read it here]. Well, Urban Re:Vision, in getting the city in on it, has made a powerful statement; Dallas actually wants to see this happen. Hats off to the hands-on approach, Re:Vision.

For everyone out there with a passion for designing tomorrow and the talent to go through with it, here are some dates for your calendar:

Competition Launch: January 26, 2009
Registration Deadline: April 15, 2009
Entry Deadline: Midday April 30, 2009
Jury Session: May 2009
Winning Designs Announced: May 21, 2009

So designers, get to it. And the cheerleaders sing: ‘Go Texas, Go Texas…’

* From the Urban Re:Vision website/blog, see it here.

** See the Re: Vision DALLAS here.

Posted under Eco Build, Environmental News

This post was written by Leif Ahnland on January 30, 2009

-->

Eco Build Directory [materials] – Hemp as a Building Material

hemp

On Hemp as a Natural Building Material

By Matt Muldoon

Hemp is an incredibly versatile construction material. A non-psychoactive member of the cannabis family, it has been cultivated around the world for at least 10,000 years. It grows voraciously, and requires no herbicides and little or no pesticides. The fibres of the plant have long been used for rope, textiles and paper, but now are also used for insulation, hempcrete, board and even roofing tiles.

Hempcrete is an exciting material that can be used as an alternative to concrete and a lot more besides. The fibres of the plant are mixed with lime to create a substance which hardens like concrete. Unlike concrete however, it is a good insulator and also breathable and very lightweight (500kg/m3). This means it can be used for walling, either cast around a wooden frame or in hempcrete blocks. It can also be used for floors, roofs and foundations.

A hempcrete building offers a healthy, pleasant environment. The hempcrete itself insulates effectively (if you’re interested: u-value for 300mm hempcrete = 0.25W/m2K.); and, as a breathable material it regulates humidity levels well, avoiding dampness and condensation problems. Since it is breathable, hempcrete would normally be finished with a lime render/plaster.

As an eco-material, hempcrete’s credentials are rock-solid, sequestering around 110kg of CO2 per m3. Hemp is a crop which can be cultivated throughout much of the habitable world, and lime production requires 80% less energy than cement production.

Hemp fibres can be used as insulation, offering a natural alternative to synthetic materials with a high embodied energy. And the fibres can also be sandwiched to make an alternative to fibreboard or wallboard.

By Matt Muldoon of the Natural Building Company

On NBM – Introduction here

On Earth as a NBM here

On Straw as a NBM here

On Lime as a NBM here

On Turf as a NBM here

To check Matt Muldoon and his company out, click here.

Read our article on him and TNBC here.

Posted under Building Services & Suppliers, Eco Build, House & Home

This post was written by Leif Ahnland on January 28, 2009

-->

Eco Build Directory [materials] – Lime as a Building Material

limestone

On Lime as a Natural Building Material

By Matt Muldoon

Virtually all traditional buildings in the UK used lime as a mortar, render, plaster or wash before cement and gypsum became more widespread in the mid 19th Century. Lime was slower to build with and required more skill, while cement allowed quicker, unskilled building as the demand for mass housing increased.

Cement and gypsum set very hard and are impervious to damp, but their success relies on maintaining this rigidity. It is inevitable that small movements will occur in a building, and as this happens cement and gypsum will develop tiny hairline cracks. Moisture is drawn into these cracks and is unable to escape. Since cement and gypsum also inhibit the passage of water vapour, these materials can also cause condensation problems.

Building materials based on lime are “soft but tough”. They work in harmony with seasonal and long-term changes in the building, accommodating tiny movements without cracking and allowing moisture to evaporate away harmlessly. Lime based building materials are not impervious to water; they slowly absorb moisture and release it, acting as a kind of moisture buffer for the materials beneath. This quality also allows lime plasters to efficiently regulate humidity levels within a building, keeping them constant and stable and avoiding condensation problems. Mould growth is very unlikely, both because of humidity regulation and because lime is a strong alkali which inhibits mould growth, and also discourages vermin from entering the walls.

Lime, like cement, is burnt in a kiln, but the process requires much less energy. Making lime requires 80% less energy than the equivalent volume of cement.

The only drawback with lime is that the building process becomes more reliant on the weather and patience of those involved: drying times for lime are very long in the winter, and it can’t be used at all if a frost is expected.

Many old buildings in the UK are suffering because of the effects of cement. Cob, clay lump, stone, timber frame and wattle and daub buildings that would have originally been rendered and plastered with lime have had cement applied to them in the 20th Century. The cement traps moisture inside the wall, reducing the strength of earth based materials (sometimes to the point of failure) and causing timber to rot and stone to crack. Buildings like these should have the cement removed and it should be replaced to lime – if not then buildings that have lasted for centuries will not last much longer.

Lime is also the key ingredient in hempcrete and limecrete.

Limecrete is, broadly speaking, an alternative to concrete. Like concrete, it uses a mixture of sand and stones, but hydraulic lime instead of cement is added. Again, carbon emissions will be much lower, but limecrete also brings the other advantages of lime to the concrete application. Limecrete is more flexible than concrete, so will continue to function where concrete cracks and it also breathable. This makes limecrete ideal for floors in old houses. Concrete floors applied in the last century force moisture sideways and into the walls, whereas limecrete floors work in harmony with the old building, absorbing and releasing to moisture to maintain fairly constant levels.

Limecrete can also be used instead of concrete in foundations. It’s become common practice in sustainable building to make foundations based on a compacted rubble trench capped with a limecrete strip. This “self-draining” foundation discourages damp and also dramatically reduces the amount of lime or cement required as much of the foundation volume is just rubble. This is gaining popularity as a modern technique, but also has a strong historical precedent: the Houses of Parliament are built on self-draining limecrete foundations.

Lime is used in natural building not just because its carbon footprint is significantly lower than that of cement. Buildings made of earth, straw and wood all need to be able to breathe to be durable. And the fact that lime provides a humidity-regulated, healthy environment is just a bonus.

.

By Matt Muldoon of the Natural Building Company

On NBM – Introduction here

On Earth as a NBM here

On Straw as a NBM here

On Hemp as a NBM here

On Turf as a NBM here

To check Matt Muldoon and his company out, click here.

Read our article on him and TNBC here.

Posted under Building Services & Suppliers, Eco Build, House & Home

This post was written by Leif Ahnland on January 19, 2009
-->

Eco Build Directory [materials] – Straw as a Building Material

On Straw as a Natural Building Material Straw

By Matt Muldoon

Straw bale building uses a sustainable resource to quickly build breathable, super-insulated structures which require little or no non-solar energy to heat if designed right.

Straw has very firm credentials as a sustainable material. Firstly, straw sequesters more carbon in itself than the carbon expended in cultivation and baling. This makes it carbon-negative from the outset. If straw is not transported too far, then it remains carbon-negative throughout its lifecycle.

Not only that; buildings whose walls are built from straw bales insulate extremely efficiently; way beyond what is required under the building regulations (if you’re interested, a typical 450mm thick bale has a u-value of 0.13W/m2K). This implies further carbon savings over the lifetime of the building, as less energy will be expended in heating.

However, there’s very little point in having super-insulated walls if you don’t have a super-insulated roof, as it’s through the roof that most heat loss occurs. Straw bales are an ideal way to insulate a roof if you have room for them. If not, you must make sure that you insulate the roof with another natural product such as sheep’s wool or hemp.

Like cob, straw is a healthy, breathable material and functions in tandem with breathable plasters and renders. A straw bale home with breathable plaster and render will self-regulate its humidity levels to provide a healthy living environment.

Straw is also (surprisingly) durable. Many of the buildings from the Nebraska settlers’ first attempts are now more than 100 years old and still standing firm. So, as yet, the upper limit for straw bale durability has not been established.

Again, straw is undergoing a massive surge in popularity. This is because of its firm sustainable credentials, its huge insulating capacity, and because of the fact that straw bale buildings tend to be soft-edged, attractive looking structures. It’s also relatively accessible to the untrained self-builder.

Straw functions well as a load-bearing material in most domestic contexts. It can easily be used as a load-bearing element in a two storey house. However, if you want to go much beyond this then it’s possible that straw will no longer function as a load-bearer. In this case, you need a structural frame built of a material such as wood, and the bales then function as infill.

Although straw bales insulate against heat loss, they do not store heat in that same way that earth does. A thick layer of internal lime or earth plaster will help, but if your design requires you to store heat then you should incorporate another element with a high thermal mass such as cob or limecrete.

Straw bale building was invented in the 19th Century by settlers in the plains of Nebraska. They needed an alternative building material where timber was scarce, and ended up with a sustainable builder’s dream.

.

By Matt Muldoon of the Natural Building Company

On NBM – Introduction here

On Earth as a NBM here

On Lime as a NBM here

On Hemp as a NBM here

On Turf as a NBM here

To check Matt Muldoon and his company out, click here.

Read our article on him and TNBC here.

Posted under Building Services & Suppliers, Eco Build, House & Home

This post was written by Leif Ahnland on January 19, 2009
-->

Eco Build Directory [materials] – Earth as a Building Material

On Earth as a Natural Building Material

By Matt Muldoon

Earth building means different things around the world. Sections of the Great Wall of China are made out of earth rammed into shuttering, prehistoric remains of earth brick cities are found throughout the Middle East, and earth brick remains the predominant building material in South and Central America. Earth can also be pressed onto wooden frameworks, as it has been for thousands of years in Africa and Europe, or just laid down in huge lumps and sculpted into wall shapes.

The key is clay. Clay is the binder that keeps the other components of earth (stone, sand, silt) together in a shapeable mass. Clay is an abundant material, but in parts of the British Isles where it’s lacking, lime and chalk have also been used as binding agents.

Earth has developed “sustainable” credentials in the last couple of decades. It’s true that the embodied energy of earth as a building material is very low, especially if it is extracted from the building site. It’s not a fantastic insulator, however, so compensation must be made with a super-insulated roof, or with extra insulation in the walls. What earth provides in abundance, however, is thermal mass. When earth is used as a walling or flooring material, a massive heat store is created. This makes earth a very useful element in passive solar designs.

Earth has also developed a reputation for “healthiness”. It will not give off any harmful materials, and as a breathable material it will regulate moisture levels in a building extremely effectively in combination with its natural plasters and renders.

Earth is durable. The oldest cob structures in the UK are 700 years old, and there is no reason they shouldn’t last many centuries more. The critical factor is moisture. Earth buildings need to sit on a plinth to keep them out of direct contact with the ground, and the roof should have a good overhang to protect the walls from long periods of driving rain.

In the UK, the four traditional methods of earth building are cob, clay lump, rammed earth and wattle and daub.

Cob is simply 20-30% clay, 70-80% aggregates (sand and stones) and about half a bale of straw per tonne of mix. The clay binds the aggregates together to create a load-bearing material, while the straw acts as natural rebar, giving tensile and sheer strength, and also aids the drying and insulating capacity of the wall.
The materials are mixed by hand, by animal, or with the backhoe of a digger, and the resulting dough-like mass is used to sculpt not only walls, but arches, chimneys and indeed any other feature that is needed. Cob is load bearing, with an average compressive strength of 0.77N/mm2, so wall thicknesses are usually between 450mm and 600mm, depending on the structure. Cob is currently enjoying a massive revival in the UK as a building material, partly because of its sustainable credentials, partly because it is a simple option for the self-builder and partly because it can be formed into shapes which are impossible with other materials.

Rammed earth, clay lump and wattle and daub are all similar in their composition to cob, though there are variations in the amount of clay used and the addition of other natural binders such as lime. Clay lump is simply cob made into bricks. The wet mix is put into moulds and allowed to dry, not fired. The resulting blocks can be laid like bricks, with clay slurry used for mortar. Because the density of the bricks tends to be higher than with cob, load bearing capacity is increased and walls can be thinner, but insulate less well. In rammed earth, the mix is wetted somewhat less than you would wet a cob mix, and then rammed into shuttering by hand or with pneumatic rams. Again, because the density is greater, you have greater load-bearing capacity but less insulation. Daub refers to a cob-like mix which is pressed onto a wooden framework, the wattle. In this type of building, a timber frame provides structural support, and the daub merely acts as an infill. For this reason, it can be very thin and quick to build, but again will not perform well from an insulation point of view.

Earth has been used for construction for at least 10,000 years, and 30% of the world’s population live in earth homes. Earth’s advantages as a building material are simple: it is everywhere, it is basically free and it is incredibly durable.

.

By Matt Muldoon of the Natural Building Company

On NBM – Introduction here

On Straw as a NBM here

On Lime as a NBM here

On Hemp as a NBM here

On Turf as a NBM here

To check Matt Muldoon and his company out, click here.

Read our article on him and TNBC here.

Posted under Building Services & Suppliers, Eco Build, House & Home

This post was written by Leif Ahnland on January 19, 2009
-->

Eco Build Directory [materials] – Natural Building Materials Introduction

On Selecting Natural Building Materials

By Matt Muldoon

By natural building materials, I mean building materials which require no or relatively small amounts of processing, and which will return to the earth without causing undue pollution. Common natural building materials are earth, straw, wood, stone, lime and hemp.

Common to all natural building materials is their low embodied energy. Embodied energy refers to the energy consumed over the lifetime of a building material, in its manufacture, processing, transportation, application and demolition. Bricks, for example, consume a huge amount of energy in that the raw materials are mined, processed, fired in a kiln, transported large distances, applied with the help of powered machinery and demolished and disposed of with more powered machinery. A contrast would be straw bales, which require relatively small amounts of energy in cultivation and processing, and the carbon cost of this energy is more than offset by the carbon sequestered by the plant itself. Straw bales also require less energy in their transportation, and at the end of their life they can be easily dismantled and left to rot.

Natural building materials also tend to be breathable – and must be used with breathable renders, plasters and paints. Breathable materials absorb and release water vapour, meaning that they regulate humidity levels well. When the air is humid, they absorb moisture; when the air is dry, they release moisture. This breath ability circumvents many of the problems caused by water vapour in modern buildings, such as excessive dampness, condensation and mould growth.

A final point to make (whilst trying not to promote natural buildings as some kind of green washed eco-lifestyle-concept) is that many people derive enormous satisfaction from being in a building whose components have an obvious link to the surrounding world. People are pleased to know that the earth walls encircling them were dug from the ground beneath their feet, that the straw keeping them so snug was grown a few fields away, or that the trees holding up the roof inside have descendents growing outside.

So, if you decide you want a building made of natural materials, what are the possible choices? It depends what you want the building to do, and what materials are available near enough to the site for their transport to be sustainable.

In designing a building, several key factors are compressive strength, insulation, thermal mass and time and cost in building. Compressive strength refers to a material’s capacity to bear a load. Earth has a high compressive strength and straw bales have a lower compressive strength. Compressive strength is a limiting factor in the weight of your building, and weight is a limiting factor in the height of your building and what you have in it. So, how high do you want the building to be? Is the roof made of something light (like corrugated metal) or something heavy (like turf)? Will the building contain normal household objects, or heavy factory machinery?

Insulation refers to a material’s capacity to trap heat inside a building. Hempcrete and straw bales are relatively good insulators; earth and limecrete are relatively bad insulators. Is it important that the building is warm? Might the building get too warm? Will the building have a heating system or will it try and do without one?

Thermal mass refers to a material’s ability to store heat and release it. Earth has a large thermal mass, straw has almost none. So, if you have a constant low level of heating then thermal mass is less important. If high level heating is provided for a few hours a day, then thermal mass is needed to stabilise temperatures between heated and unheated hours. Thermal mass is a particularly important element in passive solar design. Passive solar design is the idea of building a structure that derives ambient heating from the sun, so that it needs little or no extra heating. In a passive solar design, you need a large area for solar energy to enter the building and insulation to prevent heat escaping the building, but you also need thermal mass to stabilise temperatures between the times when there is sun and the times when there isn’t.

I don’t want to argue that natural materials are a good thing per se; but I do want to explain their advantages, and also the contexts in which these advantages apply – there’s no point in super-insulating a building if you’re only going to keep tools in it and wood is not sustainable if it’s shipped half way round the world.

.

By Matt Muldoon of the Natural Building Company

On Earth as a NBM here

On Straw as a NBM here

On Lime as a NBM here

On Hemp as a NBM here

On Turf as a NBM here

To check Matt Muldoon and his company out, click here.

Read our article on him and TNBC here.

Posted under Building Services & Suppliers, Eco Build, House & Home

This post was written by Leif Ahnland on January 19, 2009
-->

« Previous Entries