Niall’s virtual diary archives – Saturday 28 January 2023

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Saturday 28 January 2023: 22:56. Very little visible progress in the past month on my future house build as we were in the US visiting Megan’s family for much of it. I also lost a weekend to visting a site build by one of the builders we are considering in Jersey, so the only physical work I’ve got done is I finished the conduit installation on the south west of the wall, though no cable inserted as yet.

I’ve turned my attention since then to installing mains electricity into the shipping container, as I need much better lighting in there than my battery powered lantern. At the far end, I’ve raised the old florescent tube light which was in the kitchen of the house where I grew up – when they were renovating it, I claimed it from being thrown out, I’ve sat on it for years, and now it finally will go into use. That should put out about 5,000 lumen concentrated at the far end where it’s darkest. I’m also raising along one side of the container five meteres of double width LED strip angled 45 degrees downwards, and that should put out another 9,000 lumen. That should bathe in a fair bit of light eight metres of the twelve metre long container, and I reckon the door will illumate the first four metres just fine.

I made a bit of progress on the shipping container computer, but I got stuck for parts. I replaced the IRF520N solid state relays with IRF540N relays, as the latter ought to waste much less heat when derated to a 5v control signal. I found I had lost my 3.3v to 5v level shifters, so I had to order new ones. I soldered pins onto them today, so I just need to get everything wired up – well, and tested piece by piece carefully in case I accidentally shorted something.

Next weekend I head to Issaquah near Seattle for my first face to face WG21 committee meeting since the pandemic grounded all travel. I will be there for a week presenting four of my papers. I hope to get the mains lighting installed and fully functional in the shipping container before I leave, and I don’t have any ambitions this week beyond that.

One other big advancement which I think I got done is to get a mortgage application submitted. It took many more months than I could have ever expected to submit a mortgage application. Firstly we were blocked on my accountant to produce company accounts, which they didn’t complete until December. Then oodles of documentation had to be collated, because the bank/broker seems to think more information is always better, even though they clearly get overwhelmed by the complexity of it all. Then everybody seems to take at least a week and a poke from me to respond to say they need even more documentation. Nobody has actually confirmed that any application has been submitted yet, so I don’t actually know if it’s in. But that alone has sucked down a month, and the banks likely will take another six weeks to decide anything. So it’ll likely be mid April before I know whether a build commencement in 2023 is possible, or whether we’ll have to wait until 2024.

I’ve been disappointed at the lack of quotes from builders, out of thirty requests for quote dispatched, I got just one to take it to Builder’s Finish; one to take it to Second Fix; two for the superstructure only. That’s it. Some builders were blunt enough to say their order queue is full, and a passive certified build is added hassle for them which they don’t need to bother with by sticking with NZEB builds only. Last year Ireland broke its annual record for new build commencements, so no doubt that pipeline is full. However planning permission applications fell off a cliff last year, so I’m guessing that pipeline should start emptying out by 2024.

So maybe if the build commencement does get pushed into 2024, it’s no bad thing overall in terms of cost and build times. Still rather frustrating however, one is within spitting distance now. Just not there yet.

Satellite imaging

Oh, I did do one other thing: I bought an up to date satellite image of the surroundings of my site. This might sound like not a big thing, after all hasn’t Google Maps been shipping high resolution ‘satellite’ images for years now? However, firstly, Google Maps uses really old images, its one for my site are at least twelve years old, and probably fifteen. Secondly, Google’s ‘satellite’ images actually come from an airplane because the 5 - 10 cm per pixel resolution images Google has are definitely top secret nation state spy satellite type of resolution, and an airplane is way cheaper than one of those, even if Google were allowed access to one.

In fact, buying aerial images is straightforward in Ireland. If you go to, for €31 you can get a 30 cm per pixel resolution image for my site. Unfortunately, the most recent images available are from 2014.

Up to date satellite images are until just very recently not for the retail customer to purchase. The reason is cost, you can purchase them yes, but they require you to buy the whole sweep, and it’s at least several tens of thousand of dollars. On HackerNews I noticed that a startup called SkyFi finally had the bright idea of parcelling out those images in much smaller chunks for much smaller prices, ones affordable to the likes of me.

SkyFi’s pricing for my location was US$4 per square kilometre, with a minimum order of five square kilometres, so US$20 before VAT. For that, they would provide an image which captures detail over 75 cm taken in the past year. They don’t have any higher resolution images for my location unfortunately, though they do have a multispectral image a few years old with less resolution, and much higher minimum order area.

Here is SkyFi’s 75cm resolution image from 26th March 2022 11:16am cropped to match the size, but definitely not the resolution, of Google’s Maps:

Undoubtedly the SkyFi image is a pale comparison to the Google Maps image. There are some sensor blowout issues from brightness, and the lack of detail is quite disappointing.

I reckon there is approximately between a ten and a sixteen fold difference in resolution, though note that your web browser may actually be showing you a reduced resolution edition of the Google Maps image, as it is quite high resolution. At 75 cm per pixel, my site there is a mere 53 pixels wide and 52 deep, the house might be 25 pixels wide by 10 high. This is probably such low resolution as to not be particularly useful, true, but much more important here is that I can get a recent satellite image of my site for a small fee. That is very new, and very exciting, because it really won’t take long at all for pixels per dollar to dramatically improve. Commerical imagery already comes in 15 cm per pixel which is 5x better, albeit SkyFi doesn’t offer that yet, their current best is the next grade up after 75cm which is 50cm which I doubt is worth the money for my use case, as it’s only one third better. SkyFi say they’ll be selling 10 cm per pixel images by 2024 however, and that’s not far off Google Maps’ quality.

Out of interest, I looked into how much it would cost to get a man with a drone out to take aerial shots. €550 apparently. For not much more, I could buy a mid range drone with 48 megapixel camera and capture my own aerial shots in glorious 5 cm per pixel resolution.

Apart from the thrill of seeing from the sky the fruits of your labours, I suspect aerial images aren’t actually that useful for a site as small as mine. Well, at least compared to a professional survey anyway. I have a measuring tape long enough to traverse the entire site, so if I need to figure out if something is or isn’t where it is supposed to be, I can just roll out my tape and have a quicker and cheaper answer than any other solution. In that sense, these satellite images are pure navel gazing.

Am I going to spend another €25 inc VAT to get the latest satellite image when SkyFi updates it in April? To see the roof I erected, my shipping container, my portable cabin, and my other works? The chances are high. I like navel gazing!


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