One of the problems with a house built to passive house standard is that the walls are rather thick. In our case 530mm due to MBC's recommendation of a block skin on our exposed site. Add to that an incredibly strict planning policy on the park which unequivocally restricts the volume of our new dwelling to 15% of the one being demolished and we're faced with reducing our room sizes as the architect drew our plans with 350mm external walls and going back to a revised planning application is way