Having built a mock-up of the floating house just to help visualize the dimensions and the aesthetics on the land, it was time to launch it onto the water. 
As you can see from the picture above, we floated it on 12x 200L plastic drums. This provides 2400kg of buoyancy against an estimated 150kg of weight in the structure, so there was no risk of it sinking. (Unless it broke off of the floats.)
As a related plus, I finally had an excuse to go swimming in the pond.
This being the first time I’ve gone out into the pond, I explored the shallow “ledge” we built around the edge of the pond. This ledge makes it very easy to walk around. It is worth noting that the pond hasn’t fully filled in with rainwater yet. It should be another 50cm deeper once it is filled in.
For reference, here is a photo from back in June of last year when the shallow area was still visible:

The water area in the middle is another 1.5m-2m deeper, for a total depth of about 3m once the pond is full, probably about 2.5m now.

So I took a little swim over to the mock-up house and worked with one of the workers to rotate it so that the length of the house is aligned east-west (this would be the normal orientation to reduce sun exposure in order to minimize the heat effects of the sun):

Once it was reoriented, we took a look around the land to imagine what the building looks like floating in the pond.

My biggest fear was that it would be too big to easily move around the pond, or even just look like it is too big for the pond. But based on how this mock-up looked today, I think we are ready to move forward with building a house of this size (plus a meter or two of balcony).

Now we just have to finalize the design and start building.