Town Planning: Terraced houses (2)

Following the comments on the earlier post, allow me to summarise thusly:

Assuming
- plots are 9 yds wide and 36 yards deep
- the house has internal area 120 sq yds
- the garage is 3 yds wide and 8 yds deep
- you can choose between a semi-detached on the left or a terraced house on the right, which is the better layout?

I am pretty sure that the cost of building the semi-detached and separate garage is higher (in terms of foundations, bricks and roofing materials), but let's ignore that. What it boils down to is: a semi-detached with three rooms downstairs and up (of which one on each floor is usually too small) or a terraced house with two rooms downstairs and four rooms up (all OK in size)?

To my mind, the terraced layout is better: to keep everybody happy, I have pencilled in an integral garage downstairs with doors at the front and back so that people can carry mucky stuff from the garden to the front (most people will promptly convert this to an extra downstairs room, of course). And what you lose in the wasted strip of driveway at the side, you gain in a much bigger back garden (198 sq yds instead of 153); you could in fact make the terraced plot five yards shorter (lose the bit above the dotted line) and the garden is still 'better' as it is 'squarer'.
And terraced housing is almost infinitely scaleable. Here's a screenshot from Google Maps of some three-bed terraced houses in Leyton (without integral garages), including the roads in front and behind, that works out at 30 homes per acre (or "350 habitable rooms per hectare", to use the modern jargon):