But then again, the concrete is 4" thick but a good 6-7 inches deep in places, especially around the edges. It's quite possible that this could take a good soaking in a heavy downpour and retain moisture. So for the remaining beams to be bolted down to the floor, I made sure they sat on heavy duty plastic sheeting with sufficient left over to wrap up over the outer skin.
We've a 1m x 1.4m window to go in somewhere, and we decided that the north-facing wall would probably be the best place for it. Not simply because it'd be facing the house and looking over the rest of the garden (which is a bit of a bomb-site at the minute, but will be fabulous when it's been landscaped) but because the garden is south-facing, it's also something of a sun-trap.
We know from experience how hot a room can get with a south-facing window, so we've decided that the main window will be on the north wall and the two 2m windows (shown in the photo below) can go on the east-facing wall (the same side as the glass doors).
Hopefully this means I'll get the early morning sun which should be bright without being too hot. In the summer months, there should be no direct sunlight from the mid-day or late-afternoon sun (which is when it's at its hottest, here on the south coast of the UK).
The horizontal section is 75mm x 75mm, supported by the 47mm x 75mm timber (two-by-three for you old school types). This should be more than adequate to support the weight of the window. It's certainly strong enough to take my weight as I sat and dangled my legs over it - so the weight of a window is nothing in comparison!
With the horizontals in place along the floor and across the top, going from one upright post to the next, it was soon time to start building the back wall uprights.
A couple of diagonal braces really helped firm up the structure, making it good and solid with no wobble at all. Given that zero carpentry skills have gone into the building of the bungalow, it's surprisingly sturdy. I was expecting it to behave like an Ikea wardrobe - just about holding its shape but really only becoming fully rigid when the sheet/boards are fixed across the frame, tying everything together. But just the framework on its own is rock solid.
(the uprights along the back wall still need some noggins and diagonal braces and we'll be using these for fixing shelves and worktop to, so they need a little more planning yet)
Just before it got too dark to do any more, we doubled the number of rafters in the roof section so they're now less than 300mm centres - a bugger for cladding and fitting insulation, but if I'm going up there to collect apples, I want to know the roof can handle it!