We often find ourselves trying to describe how the East Bay grew over time in order to provide buyers a better idea of where homes of different vintages are most likely to be located on this side of the bay. In order to facilitate such conversations we have decided to try our hand at a bit of data visualization in the form of an interactive map showing the growth of our local built environ over time. Please feel free to try it out and let us know what you think. We will try to add more neighborhoods and more features as time permits.
Particularly interesting is the stark relief with which the map shows major events like the Oakland Hills fire of 1991 or the mid-century bay fill operations around Alameda. Even the outline of the Berkeley fire of 1923 is visible above the UC campus.
edificionado 
Hi, Christian. I just discovered this interesting tool and haven’t spent a great deal of time exploring it, but wanted to point out / remind you that County data regarding buildings’ construction date is often inaccurate. For example, the data underlying your analysis says that the house at 3025 Adeline was built in 1850, but more detailed analysis by BAHA puts the construction date at 1902-1903. I would also be incredibly surprised if the house at 1050 45th Street was actually constructed in 1860, per the data shown in your tool.
http://berkeleyheritage.com/essays/ashby_station_historic1.html
https://goo.gl/maps/ACwr1HVoue344wak8
Hi Neal,
You are right to point out that the tax records can contain all sorts of inaccuracies. The dataset was so large in this case that we didn’t try to correct any of those potential issues prior to publishing so there are likely a number of them. The hope is that the predominance of accurate information is sufficient to paint a fairly clear picture of overall trends even if not entirely correct for every individual structure.
Cheers!