Only mentions one very practical aspect of the layout in passing: The original heating system is three coal fires, plus a coal-fired stove in the kitchen/dining room at the back. In a two-up two-down arrangement these can be fed into a single chimney stack (also shared with the neighbouring house which has the mirror floor plan). If there was another set of rooms on the other side then those rooms would be permanently cold, or else you'd need a second chimney.

Each pair of houses is really built around the massive chimney. You can see it as shaded boxes on the left in the diagram in the center of the page, although these boxes underestimate the real size of the chimney-breasts:

https://cdn.theatlantic.com/assets/media/img/posts/2019/12/B...

Our house has this arrangement except a former owner removed the chimney stack at the back to get more space in the back rooms. When we moved in the chimney stack, weighing perhaps 10 tons, was resting on a piece of wood on the wooden ceiling joists - it's one of the things we have since fixed at great expense.

When you're in London and you see a building with chimneys you can tell two things: (1) It was built before 1960. (2) Count the chimney pots and it will tell you how many internal rooms there are, since each room will have its own fireplace, flue and chimney pot. eg: https://stockarch.com/images/buildings/urban/rooftops-chimne...