Fact Backed Rant

I think it might be time for a bit of explanation of why we want to wrap a perfectly good bungalow in straw.  Because - like so many buildings - it isn't actually perfectly good.  It is structurally sound and mostly weather proof, both of which are very good things, but it is also cold, very poorly insulated, would require huge amounts of energy to heat, and is massively prone to condensation-related damp problems.  By wrapping it and extending it with strawbales (along with associated works to insulate floor and roof, and careful attention to details of design and construction) we aim to produce a home that is super-insulated, so requiring very little energy to maintain comfort levels, and remaining pleasantly cool in summer.  When necessary in the coldest parts of winter top-up heat would come from a highly efficient and beautiful masonry stove  in a central position (more on these at some point in the future) from where heat can easily circulate throughout the home.
But why straw and not some more common kind of insulation material or construction technique?  I've covered this is general terms before, so this time here are some numbers to back it up.  The key figures here relate to the insulating capabilities of materials and to their embodied energy.  Embodied energy represents the amount of energy used to make a product, including extraction of raw materials, processing, transport, installation etc.  There are different means of calculating this ranging from "cradle to gate" - preferred by some manufactures at it gives the lowest figure as calculations stop at the point the product leaves the factory, to "cradle to grave" preferred by most environmentalists as it provides the most accurate estimate of the energy consumed in a material's entire lifespan.  Generally, the higher the embodied energy of a product the higher the associated carbon emission from it's production and use, though this could potentially vary depending on the processes and source of energy used.  Even when renewable energy is used it is still important to move towards low energy use throughout production though, in order to ensure sustainability of energy supply.
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