multiple parcels / multiple buildings?

[zyphlar]

On this line:

https://github.com/Nate-Wessel/hamilton-import/blob/master/conflation.sql#L157

I'm having trouble thinking of a case where multiple parcels could belong to a single building wherein the area of intersection between building and parcel is over 90%. You're basically talking about overlapping parcels which I'm unsure if are likely to exist especially in my data set. Far more often you see condo buildings divided up by parcel: a duplex in half, a triplex in thirds, etc. I suppose if an area had a ton of townhouses where the first floor and second floor were different parcels this query might work..?

Any thoughts on this issue? I also modified the next query for addresses on buildings across multiple parcels (which seems like the same exact problem, right?) to rather than finding areas of intersection under 90% (which was unfortunately assigning slivers of secondary buildings to the wrong side of the street and creating duplicate addresses in my dataset) now instead finding areas of intersection over 50%.

[Nate-Wessel]

I think the original issue here was that this dataset represented condo ownership and the like by fully duplicating the whole parcel geometry, just with different data for ownership, etc. So we had some parcel geometries + addresses replicated up to 10-20 times.

The 90% rule was for imperfect alignment between buildings and parcels if I remember right... I think sometimes a building was built across multiple parcels probably owned by the same person but not legally combined. My thinking was that if there was any doubt about which parcel's address to use ( i.e. 90% vs 50% ) to just not assign that building an address from the parcel. Better to know what you don't know.

[zyphlar]

Gotcha thanks for the clarification! I'll have to see how condo ownership is represented here.

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On Mon, May 10, 2021, 5:12 AM Nate Wessel ***@***.***> wrote: I think the original issue here was that this dataset represented condo ownership and the like by fully duplicating the whole parcel geometry, just with different data for ownership, etc. So we had some parcel geometries + addresses replicated up to 10-20 times. The 90% rule was for imperfect alignment between buildings and parcels if I remember right... I think sometimes a building was built across multiple parcels probably owned by the same person but not legally combined. My thinking was that if there was any doubt about which parcel's address to use ( i.e. 90% vs 50% ) to just not assign that building an address from the parcel. Better to know what you don't know. — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub <#1 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAAL2MS6MTNF6IGEVGHF2VDTM7ETBANCNFSM44FRUB2Q> .