First ground broken. My friend here won't let me help digging, presumably so as not to dishonour his guest. But I refused to let him refuse my additional digging services.

A van full of supplies, picked up from Lahore. Collection of an order in the UK would take 10 minutes. In Pakistan, after you've had the small talk, chai & pakora, exchange of family news, lunch, inspected and picked up the stuff, and carried out various other miscellaneous errands, it takes a little longer. 6 hours in our case.

Foundations taking shape.

Meanwhile in the workshop, the 1st frame is complete. 9 more to go.

Need to glue any synthetic Muslims? Lots of things are labelled 'Muslim', from household products to education systems. In this case I suspect it's referring to lack of pigs.

Setting the legs into the concrete.

Starting to get the frames put into position. This modular approach was necessary as the complete prototype unit was so heavy it took 5 men to move. This way we'll drop the panels into place, then fit the outer components.

I needed something to keep me sane during the frequent and inevitable delays in the main construction, so I put together this Arduino-based temperature logging system. Mounting the circuitry in a tapering cylindrical tub was an interesting geometrical challenge.

Frames complete.

Panel construction: this takes two people - one to tighten the vice, the other to stand on top so that those two L-brackets pinch the sheet metal in around the copper tubes.

Pakistani recycling at its finest. On the outside the box looked like a conventional enough packet of screws.

Lots of screws later, the first panel is finished. None of the machinery had safety guards, but this bandsaw frightened me the most. Especially on the day when the blade fractured. Let's just say it was fortunate that no one was standing between it and the wall.

Cutting notches for the pipes to run through.

This chap and his apprentice came up from Lahore to braze the panels' plumbing together.

One leak out of 180 brazes ain't bad.

Cutting screw threads into the ends of pipes. The plumbing took a long time...

Coiling the heat exchangers.

Mr plumber in his element.

Heat exchangers mounted in the tank.

In the nicest possible way, they're not great at forward planning. When we came to doing some plumbing work on this tank, we discovered that no-one had ever thought to install a stop valve at the bottom. Solution: plumb very fast to install a valve before all the water escapes!

My temperature logger (and keeping-myself-sane-during-the-frequent-and-inevitable-delays project) - on a cloudy day by the looks of things - 70-80°C would be more typical on a clear day.

Much like peeling off a huge sticking plaster, and equally satisfying. This glazing was shipped by painted truck from Karachi, and only came in the frankly bizarre size of 6'11" x 19'. The relative expense of this component meant I sized the entire design around it.

The official opening ceremony. Though we squeezed in a few more days' work on it before we actually left.

Some of my main helpers.

Finished! (At least, for a given value of "finished".) Just in time for the monsoon season...

The maintenance staff.