Thats normal the windows are so small. The bigger windows, the more cold wind is getting inside. Windows are expensive, not only glass, but it is much faster and easier to build just a wall. Remember these houses aren't from stones or bricks, but wood. EDIT: (In fact some seems to be made partially of some stone material, but this what keeps it together is still wood.) I suppose there is also no glass in these windows, but these membranes made from something inside some animals

The houses with big glass windows are owned probably by very rich people.
Concluding, i think some glass windows in sme houses are too big and in other houses with these tiny windows too small.
It is mainly due to a fact, that there are only few textures for walls and some were made without good proportions and other are so badly resized, while it should tile more or less. Finally, the building wall lengts can't be very custon if there are only few textures. The fact there are no windows at level one is also due to texturing errors.
Although there is room for progress, thanx to this our RAM isn't that much used while the Hydlaa is loaded.