Here's a model I made of the Design Museum in London.

As you can see, I ran out of white bricks half way through, and didn't have the money to buy any more. I did offer to finish it (and donate it to the museum) but I go no takers. It's one of the rare situations I considered a kickstarter.

On the plus side, I did get a 'favourite' from the museum on Twitter. (Which is a very minor point, TBH!)