It's heating up here now, and thankfully the awnings seem to be doing their job. Outside temperatures are getting up into the high 30s some days while inside we have had a max of 25ºC - warm, but nowhere near as hot as outside and quite tolerable. This photo shows the planter with the awnings down outside. The plants don't seem to mind the shade too much.
The changes we made to the grey water system (sending the kitchen and washing machine water straight out into the septic instead of into the planter) have worked brilliantly. The whole thing smells better - in fact, doesn't smell at all - the water is cleaner looking in the toilet, and there is no overflow whatsoever and no revolting grease trap to clean. We are immensely pleased with it. So, if you do decide to make a grey water planter, remember to divert the kitchen water straight out to the septic to avoid all that grossness.
We have also (finally!) put doors on all of our cupboards. It was the last proper building sort of job that had to be done, so I guess that means we have really and truly finished the house (in as far as it can ever be finished). Wow.
Outside our windows my flowers have all come up beautifully and are happily nodding away in the breeze with the bees busy about them. Happy summer (or winter if you are in the southern hemisphere) everybody!