1. Pick Settlements in your keep, ignore all other future upgrades. Stay at 1/6!
   
2. Place Cottages and wells near the edges of your map.
   
3. Do so until you get the 3. card of Settlements, which is houses.
   
4. Start clustering the 4 Houses districts around your keep in a spiral going outwards. Each one gives you an additional House.
   
5. As you do so, take Cards 1 by 1, let the Cards stack up as high as possible, so you grab them later. The higher your city rank is (Village, City, Metropolis) the more cards you get per deck.
   
6. Go spam Houses, thats it.

This works, because you lock yourself to only using the Settlements deck, which is guaranteed to appear every time you draw a new one, since its the only one you specced into.

To the devs reading this, you can fix this by forcing people to upgrade the Keep, as soon as it becomes available. That way, you cant just draw settlements only and this strategy falls apart.
Alternatively or in addition, make it so clustering 4 houses grants a cottage instead and that clustering 4 cottages gives a house. This way playing smart can get you an early House card, while spamming Houses wont be as sustainable.