Architectural detail: Deck flush with lawn

For a long time, I couldn't get these images out of my head.

[Lanciano Design via freshome]

[GASS Architecture via freshome]

Yes, yes, they're beautiful homes, lovely weather, inviting pool, etc.  But the part that really captured my imagination was the deck.  I loved how it ext-e-n-ds the indoor to the outdoor, building to nature.  How did they build the deck flush with the lawn?  A conversation with a co-worker (who builds decks in his spare time) answered my question.

The area under the deck is excavated slightly, just enough to keep the earth from touching the wood.  There will be some more prep work (sand, gravel, possible french drain) to ensure good drainage, similar to strategies used under greenhouses.  After that, it's built like any other deck, but omitting the posts between the concrete footing and the joists.*  Then you'll need some kind of trim that will retain the soil under the lawn to keep it from eroding.  It could be stone (like the sketch below) and there could be a nice reveal between the deck and lawn.  Or it could be plastic and set slightly lower so it is covered by the decking.

Also, I think it would require some careful mowing, just in case.

In theory, you could get something similar with concrete (like the area around the pool in the second picture), but the tactile feel of wood underfoot is so much friendlier than concrete that I think it might be worth the extra effort.

*Most decks have posts to raise them up because the ground floor of the house is usually a few steps higher than the landscape.  So I guess the real trick to getting the open, flow-y feeling in the inspiration pictures is lowering the house to grade.