drdesignz, on 02 October 2012 - 06:35 PM, said:

Uh oh:

movoto.com said:

We came up with this figure by first figuring out the size of a standard eight-peg LEGO in inches. We found an excellent resource on LEGO brick dimensions and with some converting from millimeters to inches we had the size of a LEGO: about .26 x .62 x 1.22 inches.

Ouch.

A 2x4 brick measures 9.6mm x 16mm x 32mm. That translates to 0.378" x 0.630" x 1.260". They need a lesson in metric conversion, apparently!

movoto.com said:

After we figured this out we researched the standard size of a brick in the States: 2 1/4 x 4 x 8 inches. The end result: 359 LEGOs per brick.

That's about 12.7 studs x 25.4 studs x 5.9 bricks. If they went for "roughly-same-size-but-complete" brick, I'd go with about 12 studs wide by 26 studs long by 6 bricks tall. Using 2x4 bricks, I'd lay them out in rows such that they were 3 2x4's laid end-to-end to make up the width, then 13 side-by-side to make up the length, and stacked 6 tall. So, 3x13x6, or 234 per brick, not 359, which is off by quite a quite a lot, considering that this is going to be the base of their calculations! Otherwise, if you went for an average (as in, it'll average out over distance), it's about 240.04 per brick-- still off by a more than 100 bricks!

Then there's the fact that they seem to be basing their estimate for bricks based solely on the exterior walls of the house-- not including the floors/ceilings, roof, foundation, or interior structure.

[edit]Also, they're basing their information on some guy's response on Quora. He doesn't take mortar into account, and assumes a 1500 square foot house would be "for simplicity" 15'x100', which is 230' of perimeter, rather than something more realistic, like 30'x50', which would be 160' perimeter (the ratio matters quite a lot!). Also, the Quora post doesn't account for pitched roofs, windows, doors, or other things-- it's just some guy trying to estimate using math, without taking into account any features of reality. ... Not that it really matters for the purposes of making a LEGO house, since you may not WANT a pitched roof, and you DON'T want to include mortar (which just adds extra spacing).

FWIW, my guess for the Quora post is roughly 9,100 bricks, assuming 30'x50', 1 storey, hip roof, 0.5" mortar spacing, 12 windows, 2 exterior doors, based on a more-or-less standard floorplan layout. That's just under half of the answer given (18,400), which (if correct) means that the calculator is off by a factor of 2, just in the number of bricks needed, plus an extra 50% over-estimation based on the incorrect brick size. (I admittedly didn't take into account the overlap in corners, but that shouldn't add too much) So, about 250% overestimation for that calculator, if I'm reading it right.

The far better source for a LEGO house would be to assume that it would follow the "James May Standard", using the large-scale assembled bricks that they used. The math involved is simple enough-- why would they bother trying to trace it back to some extremely sketchy Quora post?[/edit]

Color me unimpressed with their calculator :(

drdesignz, on 02 October 2012 - 06:35 PM, said:

The bottom line is, it's impossible to come up with an exact quantity of Lego bricks for such a concept. Although, you could somewhat accurately calculate the number of bricks required for a large hollow sphere, if all bricks were the same size. A solid sphere would also be possible, I suppose. Either way the numbers are astronomical.

Yeah, the practicality is so out-the-window that the exact figures don't make much sense-- but they can provide you with some idea of just how astronomically large such a construction would be!

DaveE

**Edited by davee123, 02 October 2012 - 10:09 PM.**