You can also convert Forges, Farms, Mines, or Training Camps to a Barracks, Hunter’s Lodge, and Alchemy Lab — and eventually to Hero Academy, when it’s released. Typically using a Forge is preferable.
There are also Advanced versions of Iron Storage, Food Storage, Farms, Mines, and the House that unlock with SH21 and SH22. These are converted from the existing equivalent building.
As @zephyr1 listed out everyone gets the same amount of each building. The game doesn’t let us have more or less of one type unless it has been converted. So, build those buildings and level them. There’s no strategy to it.
Correct! Since the OP appeared to be down to his last buildings I was thinking of that. Thanks for the clarification as I can see that being confusing for others possibly reading this