Our long-listed competition entry for the Cambridgeshire Great Fens wetlands visitor's centre demonstrates a high level of sustainability, community involvement, and striking use of form. Inspired by timber bird-watching towers, the main building soars upward, providing an outstanding observation area; a landmark in a very flat landscape. The associated office building is clad and roofed in local thatch, a nod to the historical use of local reed crops. Both structures are built of timber frame with straw bale infill panels, another local product. The simplicity of the construction method allows the Great Fen partners and local enthusiasts to build much of the structure themselves, giving a sense of pride and ownership. The structure is nearly carbon-zero with almost all materials sourced within 100 miles, solar PV and hot water, ground source heat pumps, a reed-bed filtration and grey water recycling system, and the excellent insulation qualities of the dense straw bale construction.