These 2 buildings are the most unknown buildings to me. I am not really sure of their purpose towards specializing a city, or if they even have one. Can anyone tell me if they use them? And for what?

For general purpose, they are actually much better than the other improvement, except towns. It does not have any specialization however.

Windmills are a way to add some food to a city that has a lot of hills and little good land to produce food. Watermills can actually be very productive, both in food and production as you get into the late game. I use them much more than I do Windmills now.

I believe they will also both add income to your city, which is always a good thing.

Windmills turn a resource tile into a mixed-production tile. They are great in commerce cities from the minute you get them. For resource cities, you'll want to use them sparingly until later on.

Watermills turn a commerce tile (usually) into a mixed-production or even resource oriented tile. You generally shouldn't use them until later on, in a production town.

In both cases, the key tech in terms of widespread usage of these improvements is actually biology. Biology allows you to create a food surplus via irrigation in almost any town. This tends to allow other tiles which had been producing food to be freed to produce something else, which is when you'll often put a wind or water mill there.

As a simplification, just look at their power (food + hammers). I'm not considering everything, in particular the base terrain values, and the needs of a highly-specialized commerce city.


Mines are +2 power.
Farms, windmills, watermills, and workshops are +1 power. (pre-replacable parts, post-guilds)

So, generally speaking, you want to build mines.
You build the other things because you can't build mines.
Therefore, the other things should be geared towards food production! (Because food lets you work more mines)

Windmills are best (extra commerce), but consumes tiles that might be better used for mines.
Farms are next. They give food.
Watermills are next. They don't give food, and thus don't help you work more mines, but at least they give a hammer.
Workshops are the worst. They actually hinder your ability to work mines.

(Of course, if you have noplace to build mines, then watermills and workshops suddenly become useful)


Once you get replacable parts, things change. Watermills, windmills, and workshops all become two power tiles.

So now your goal is to work as few farms as possible. So...

Windmills are the best. They give you more food. (And commerce!)
Mines are mines. Use when the extra food of a windmill cannot be helpful.
Watermills are the same as mines. But they're still better than farms!
Workshops are the worst. They increase your dependence on farms.


When you get railroad, things swing back the other way slightly, because mines become 3 power.

Your goal now is to maximize {# mines} - {# farms}. (Assuming the remaining tiles all have windmills / watermills / workshops)

If working a mine would require an extra farm, then you want a windmill instead. (Extra commerce!)

Watermills should be built whenever possible.

Workshops are still bad, because they increase your dependence on farms.


With electricity, windmills and watermills become more tempting due to the extra commerce.


With biology, we come full circle. Mines are the only 3 power tile, and all the others are still two power. Once again, we want to build as many mines as possible, and thus emphasizing food production.

Farms are best.
Windmills are next. But, they consume tiles that can be farmed.
Watermills are next.
Workshops are worst.


State property throws a wrench into things. Workshops and watermills become 3-power tiles, so we want to avoid windmills and farms.

So, watermills become the best tile, because they give extra food, thus reducing dependence on windmills/farms.

Mines and workshops are equivalent on the surface (+3 hammers)...

But windmills are preferable to farms (especially pre-biology). Therefore, we should build workshops before we build mines.

You cannot compare windmill with farms. You can only build windmill on hills and farms on flatland. There isn't a choice to choose one over the other.

Sure you can compare them to farms, so long as there is both flatland and hills within one city. Production of food applies city-wide.

Windmills allow you to add food and commerce to hills, watermills allow you to add commerce and production to "straight" non-hill river tiles. I find them to be excellent improvements for rounding out my cities.

Farms allow you to add specialists to cities which gives you the option of specifying whether you want gold, science, hammers or culture.

It might be worth noting that watermills are also the only kind of improvement buildable on Ice tiles(only with a river next to them). This particular feature has really helped me in some high-sealevel Archipelago games, where you're sometimes forced to settle cities in less good areas.

I'm playing a highlands game right now, and windmills are my best friends.

My favorite improvement is the watermill. I'll build them along a river unless it's a plains (which I farm), or a commerce/science city, in which case I'll mix cottages and farms. Windmills allow your hilly tundra cities to grow large enough to be useful.