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statistical-modeling-for-construction-estimating.md

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+---
+id:
+aliases: []
+title: Statistical Modeling for Construction Estimating
+tags:
+  - authorship/original
+  - destiny/permanent
+  - status/incomplete
+  - topic/construction
+  - topic/estimating
+  - topic/math/statistics
+  - type/cross-topic
+---
+# Statistical Modeling for Construction Estimating
+
+Cross-topic of [[statistical-modeling]] and [[construction-estimating]].
+
+## Bayesian Takeoff
+
+#### User Story
+
+Frank is estimating a 20-story high rise
+and notices that their are roughly, but not exactly,
+the same number of receptacles in the corridors of levels 2 to 19.
+Frank starts a new takeoff for duplex receptacles,
+typical of levels 2 to 19.
+He counts and inputs quantities for 3 levels,
+each adjusts the prior to calculate the expected quantity for all 18 levels.
+
+## Stochastic Branch Takeoff
+
+generate a BOM from point loads distributed in a space.
+
+```yaml
+- x: 302.84
+  y: 2364.47
+  kW: 5.3
+  voltage: 277
+  phases: 1
+...
+```
+
+determine relative impact of factors
+* allowable voltage drop
+
+## Methods
+
+> [!cite] Reddit u/mightofmerchants
+> ![[spatial-sampling.gif|300x300]]
+
+* Poisson disc sampling
+* Delunay triangulation
+* Voronoi diagrams
+
+%% TODO: link paper on procedural generation of single family homes %%
+
+## Average Distance Given Area
+
+Holding area constant,
+average taxicab distance between points
+varies greatly with the aspect ratio of the space.
+Weighted by a probability distribution
+an average length and confidence could be given for any known area.
+
+[[sigmoid-functions]]
+
+Maximum area per floor is sometimes capped by
+[[ibc-construction-types]] or [[ibc-occupancy-classifications]],
+either directly (see [[ibc_ch05]], [[ibc_ch09]]),
+or by maximum travel distance (see [[ibc_ch10]]).
+Stairwells are expensive. There are usually only 2 or 3.