The Groundhouse is an earth-sheltered house built in Brittany by Daren Howarth and his partner in 2009. It is designed to be aligned with natural systems. The aim was to build a home based on the most sustainable design, systems and materials. They have a great website with lots of pictures of the build and some great summaries of build techniques and materials.  They are currently working on other projects which includes research for UK affordable eco-housing (community land trusts, low carbon development zones and planning covenants). On his website Daren argues that we can select “build forms that achieve modern levels of durability and comfort and which can be simple, ecological and affordable: simple means not just lower costs but also the possibility for building or renovating your own home; ecological means designs that work with the land and the elements; and affordable means below average build costs and low running costs”. Moreover, he notes that “The biggest barrier to living in a natural home is often inflated land values that make homes unaffordable”.