
Many details are still unclear, naturally, but in recent weeks most of the big questions regarding the Lennon-era layout of Kenwood have been answered, thanks to the 1964 Ken Partridge plans, and one or two "new" uncropped photos. The biggest remaining mystery concerns the north-west end of the house, as seen above; it constitutes (or constituted) a fair chunk of real estate, but what exactly did it contain?
The answer might just surprise you. But probably not.
First, let's remind "us-selves" of the changes this section underwent during the '95 renovations. The whole area from the sunroom on was demolished and re-built.
Compare the following:

Notice also the comparative sizes of the old, Tarrant built, and new, '95-era garages above. Next, take a look at this, very familiar, picture:

"So what?" I hear you mutter, "This was taken in the garage, right?"
Well, yes and no. The old garage looks too small to accommodate a Roller and a Mini, and it occurred to me that some other details didn't quite fit, either; eg where is the canopy that can be seen in the John photo? So I had a look again at the colour aerial shot...and sure enough, there
is a canopy attached to the north west extension...

The clincher would seem to be this '95 plan (pre-renovation), which does what the Partridge
plan doesn't - namely, shows the sunroom (albeit the '95 version) and the north-west extension (ditto), canopy in place, and labelled "GARAGE":

So what might well have lain behind that window overlooking the swimming pool was one or other of John's automobiles. This would make sense, for several reasons; John, at that point, had a weakness for cars - at any one time he owned at least 3, including the Rolls. Cynthia also had at least one. It's possible the big extension housed John's "wheels", and the much smaller old garage was home to Cyn's. It might also explain why this part of the house doesn't show up on the Partridge plans - because, applying Occam's razor, it simply didn't exist at that point. John could have had the extension built precisely because he needed more storage space for his cars, the unenvironmentally sound little moptop that he was. (UPDATE - The account of the June '67 visit to Kenwood in the Beatles Book monthly has this to say at one point: "John led the way to the massive double garage at the right hand side of the house". That
has to refer to the north-west extension; the old Tarrant garage is clearly very small.)
It would also explain why the Tarrant garage was demolished and rebuilt in '95 - because what had been the main (extension) garage was being converted to a games room, thus making the construction of a bigger "external" garage necessary.
As to
when the original sunroom and extension were constructed, it's hard to say - but presumably during the huge round of renovation that accompanied John's initial purchase of the property; late 1964/early 1965. More on this bit, inevitably, to follow...