This may not be the most exciting post ever, but we’re aiming to cover everything it takes to complete this house (and document its performance and what it’s like to live in afterwards), so sometimes that means the more mundane aspects. Today, it’s parging – in this case, finally, covering up the polystyrene foundation insulation. Even parging isn’t just a simple matter of throwing some plaster at a wall, however. First there is a two-layer undercoat with an insect screen in between. This undercoat is a polymer plaster which also contains fibreglass. It’s strong and protective but remains flexible even after it’s dried, which means it will cope with any heat-related expansion and contraction, or movement without cracking or flaking off. Next week, we will add another coat of finishing plaster which will be in a blue-grey colour like the siding, but will have some texture to it.