Our (second) house is a typical 1960s detached brick house. Cavity wall, concrete floor, tiled roof (with skeilings. These pages describe the process of refurbishing it over a decade or so to (just about) passivehous (Enerphit) standard, and adding an extension to connect house and garage.
Most of this work has been done DIY, with some tradespeople for particular jobs (plastering, tiling, rendering, capentry) and a local builder did the extension shell. We did all the design work, drawings, calculations and planning applications ourselves. As a result I know a lot more about building retrofit now than when I started, so if I was starting now, some decisions would be different.
One of those decisions is that we started off doing IWI (internal wall insulation) because it was cheaper, and easier to DIY, and produced a reasonably decent thermal result, but we switched to EWI (External Wall insulation) for the North half of the house because it was very difficult to do a good job on the wall containing staircase, kitchen, bathroom and small toilet and our standards rose during the project from the original 'Carbonlite silver (~60% improvement) to Passivehouse Enerphit (90% improvement). This means that this one house has examples of both IWI and EWI so we can compare and contrast.
I hope these pages will give sufficient info on the design process to be useful to others undertaking similar tasks. The info is organised by subject rather than time as that provides a more useful overview. This is all a work in progress and may never be complete...
Note that I am an engineer, not a web-designer, so these pages generally look horrible. There is a lot of good info in here though, so it's worth persevering :-)