How a model is made

A LotLens Model kit is a paper model of a house that exists, made from public data. This page says what the model rests on, how it is measured and unfolded, which checks every kit passes, and what a kit is not.

A model to build, not a survey: nothing in a kit is a measured drawing of the house.

What the model rests on

• The roof: public lidar, the USGS 3D Elevation Program in the United States. Before anything is measured, the start page checks that a survey covers the pin; without one there is no order.
• The aerial photograph: the USDA National Agriculture Imagery Program, for the picture on the order page and for choosing the roof where several stand at the pin. The model is measured without it when it does not answer.
• Windows and doors: Google Street View frames, at most one per wall a street sees, read once and deleted.
• The walls: the roof’s edge, set in by the overhang measured on each wall where a picture shows it, and by a fixed depth otherwise.

How it is made

The house at your pin is found in the lidar among the trees around it, and its roof is read as planes: a ridge, hips, the pitch of each face. Where a tree hides part of a roof the model completes it from the parts the laser saw, so that every kit closes. The walls stand under the roof’s edge.

Windows and doors are read from street-level frames: an AI model marks their corners on the picture, and the engine measures them against the wall it knows from the lidar. A wall no street sees gets its openings drawn dotted, where houses usually have them. The numbers never come from the AI model; it points, the engine measures.

The model is then unfolded into sheets at the scale and paper you choose, with glue tabs, an overview page of the pieces and their joints, a page on how to build it, and a 100 mm ruler to check the print. Another size later costs nothing.

The six checks

Every kit is checked before it is offered: no piece narrower than 3 mm at its scale, every piece inside its sheet, every fold landing on its neighbour, room for every glue tab, the sheets reading back at true size, and the model closed. A kit that misses a check is still yours, and says in one sentence what that check means for the builder, in the kit and on the order page.

What a kit is not

It is a model to build, not a survey or a drawing of the house: the roof is as the lidar saw it on the day of the survey, the walls follow the roof, and an opening a street never saw is a guess drawn dotted. How close a kit comes to measured drawings of the same house is being measured now; no figure is claimed here until it is.

Your data

An order keeps the pin, the address, the model and the kits. Street View frames are read once and deleted, never shown or stored. The privacy notice says the rest.

Sizes, scales and the price: pricing. The Lot Report’s own method page: how the rules are read and checked.