I think most readers of J. R. R. Tolkien are familiar with a town of which the Mayor was fat and of which a watchman, Bard, was moody. In the English "translation from Westron" it was Laketown, in Sindarin (or Doriathrin) it was Esgaroth.
There was a Laketown in what is now Switzerland too. Wait, verifying on wiki, there were more than one. And all around the Alps, from France to Slovenia. I was probably thinking of the very well known one in the lake of Zurich. The piles have been found, but little else has, as far as I know, which leaves a lot of room for imagination.
In fact, they are probably all smaller than Esgaroth, as to what one has found. But there are 111 sites, or rather these are a selection from 937 ones. Here is Unesco on them:
Prehistoric Pile Dwellings around the Alps
This serial property of 111 small individual sites encompasses the remains of prehistoric pile-dwelling (or stilt house) settlements in and around the Alps built from around 5000 to 500 B.C. on the edges of lakes, rivers or wetlands. Excavations, only conducted in some of the sites, have yielded evidence that provides insight into life in prehistoric times during the Neolithic and Bronze Age in Alpine Europe and the way communities interacted with their environment. Fifty-six of the sites are located in Switzerland. The settlements are a unique group of exceptionally well-preserved and culturally rich archaeological sites, which constitute one of the most important sources for the study of early agrarian societies in the region.
Description is available under license CC-BY-SA IGO 3.0
Now, when is this?
5000 BC is a carbon date which is a misdate. It is from a time when carbon 14 levels were lower, since even carbon date 3100 or 3200 (at most recent 2900) BC is actually the time of Genesis 13 and 14, around 1940 - 30 BC.
So, one can presume, the inhabitants of the laketowns arrived, at least the earliest of them, dated 5000 or 4000 BC, when Abraham was a child or before he was born, perhaps even a few centuries before he was born. However, the latest ones, around 500 BC, are from a time when atmosphere already had a the present ratio of carbon 14 to carbon 12, meaning the carbon date 500 BC probably does correspond to a real date 500 BC.
Why is this important? Well, Ninus lived about the times of Abraham, and he is the founder of the idolatrous type of paganism, the idolatry of Babylon. While the earliest inhabitants were no longer speaking Hebrew, they might still have worshipped the true God. Here is from my own translation of Peter Comestor:
Meanwhile they obtained Egyptians and Assyrians thus: In the days of Sarug, Belus the Nerothid [=?=Nemrothid, with a missed nasal stroke?] the king of Babylon, because there was another Belus, king of Greece, entered Assyria, but obtained too little therein. When he died, his son Ninus obtained all Assyria, and amplified the city in which the head of the kingdom was by the day's march of three days, and called it Ninive after his name.
This is why some histories say that the kingdom of Assyrians started with old Belus: which is true as far as the beginning is concerned. Others say it started with Ninus, which is also true, as far as the enlargement of the kingdom. Ninus defeated Cham [!] who was still alive and ruled in Thracia, and was called Zoroaster, inventor of magic arts, who also inscirbed the seven liberal arts in fourteen columns, seven of bronze and seven of tiles, against either doom (?). But Ninus burned his books. From these the same, idols were thus begun:
On the Death of Belus and the Beginning of Idols
When Belus was dead, Ninus, in consolation of the grief, made himself an image of the father, to which he showed such reverence, that he spared all criminals who took refuge to it. Accordingly people of his reign started to impend divine honours in the image; by example hereof many dedicated images to their celebrated dead ones, and as from the idol of Belus the others took their origin, so of his name they took the general name of idols. As he was called Belus by Assyrians, so also other nations according to the idiom of their tongues, named some of the Bel, some Beel, some Baal, some Baalim. Even more, they specified names, some saying Beelphegor, some saying Beelzebub. But at last let us pursue the genealogical series of Shem.
So, presumably, when we see clear idols emerging in Mesopotamia, we can consider we are dealing with the days of Sarug. Note also, Sumeria is not the oldest place in Mesopotamia, but Göbekli Tepe seems to be from before idolatry. This means, carbon date 5000 BC in the Alps may be earlier but need not be so. This is then perhaps from pre-idolatry times, and considering how far it is from Mesopotamia, probably from a pre-idolatry population.
So, how would one reconstruct the dwellings?
In Tolkien's Laketown, you have houses like those found in Norway on the coast : tall wooden houses with vertical planks where the architecture, much like Edoras in the Peter Jackson films, recalls the stave churches of Norway. In fact, the reconstruction at Lac de Chalain, rive occidentale, next to original piles, or stumps of them, also has vertical planks, perhaps because the archaeologists were Tolkien fans. However, they have proven that vertical planks are at least technically possible.
In Tolkien's Laketown each house or each wealthier house had more than one storey, like two or perhaps three including the ground level. In the Middle Ages, which he was aligning his prehistoric uchronia with, a tradesman would have his shop in the ground level and his living space upstairs.
This would be one way to avoid the cold of the water which was even colder for being shaded by the houses.
In the reconstruction, by Unesco, there was one storey. Supposing this correct, how did the inhabitants avoid freezing? One idea is, they would have been living there in summer for some coolness. Another is, they would have had plenty of textiles inside, insulating the ground floor and walls. And obviously, if you would hardly light a fire directly on the planks, you could perhaps still have some kind of hearth in a ceramic firepot - even the oldest of the cultures involved have ceramics.
Firepots already existed around the time of Babel (Göbekli Tepe) in what is now South America:
Fell’s Cave, a rock shelter in the valley of the Río Chico not far from the Strait of Magellan, was initially occupied by hunters around 10,000 B.C. who left behind an impressive layer of refuse. Sealed by hundreds of pounds of debris from the fall of the shelter overhang, the hunter’s refuse included firepots with the broken bones of native horse, sloth, and guanaco, as well as stone and bone tools.
Or perhaps, the reconstruction could have two storeys with a ladder between them once you were inside? And plenty of hay under your buttocks. That can also keep you fairly warm.
Would firepots have been constructed so that they could be safe even close to hay? Possibly, if you were very careful.
What would have been the political structure of these dwellings? If one had found a large one, as large as a town, one could imagine Tolkien's alignment with a Medieval commercial city state would have been appropriate. As small as the ones we do find are, perhaps more like small villages. Were they or weren't they connected over larger areas? We don't know.
And considering the area, we could imagine that the inhabitants were descending from Gomer. They could have been speaking what later became Celtic when it was more Indo-Europeanised by Sprachbund phenomena.
Imagine you had been wandering for some hours in a winter day, and you arrived in the evening. You walked out on a wooden ponton, a raft tied to both the lake shore and the house. You sounded a brass bell, someone looked at you using a firepot as a lantern, and then said "come in". He lowered a ladder to the raft, you climbed up, you came in through heavy curtains of textile, and it was warm and they were sitting around a firepot, man, wife, children, youngest adult son who had welcomed you standing up and telling "we have a visitor" and the father of the household telling you "sit down". And whatever served them for tea, perhaps holly, was given as a hot drink, while a plate of meat and vegetables was prepared for you.
Don't tell me everyone was miserable prior to the industrial revolution.
Hans Georg Lundahl
Chair of St. Peter in Rome