Most of the early design thinking was carried out using Microsoft PowerPoint and a copy of these outline plans can be downloaded in PDF format here.
But I also wanted to visualise the basic structure in order to have confidence that the proportions were suitable. So, as for the tea house, I made use of Google Sketchup to create a 3D model. For those who have Sketchup installed, this is also available for download as a zipped file here.