Onto second fix of Passivhaus vet surgery. Electrician has supplied today commercial LED bulkhead and strip lights. Obviously lighting is important in a vet surgery but with what the electrician has provided this will now be the major energy use in the building. Quite a few of them double as emergency lights and have batteries. They all seem to be single unit manufacture- so require the whole unit to be replaced if they break, not great from an E waste perspective. I don't understand why they seem so much more complex than domestic bulbs, why they have a lower lumens to watts ratio than simple bulbs from Asda and why they cost 10x the price.
Can anyone shed any light!

I've noticed a growing trend towards supplying luminaires with "non replaceable" LED lamps, effectively sealed, so chuck the whole lot when it fails.
I guess it was inevitable as LEDs, with their longer life, hit manufacturer's profits so they had to find a way of "adding value" to their products.
Off topic but;
Convenience, and versatility aside, I'm unsure generally of how much positive impact domestic LED lamps have had on energy saving in industrialised societies, which is how they were originally sold.
Their proliferation into hitherto non-illuminated areas of living, e.g. kitchen plinth lighting, shelf lighting, outdoor garden lighting generally, indoor and outdoor "art" lighting etc., with all the extra manufacturing energy use it generates, probably more than outweighs the direct energy saving. Plus the knock on effect in individual thinking e.g. " Oh leave it on, it uses so little power anyway " is surely detrimental.
One side effect that this, all night illumination, has had on wildlife for instance has only just begun to be recognised.

Led strips.

Not directly addressing your situation, I have spent that last 12 years watching the Led strip/lighting market. Installed a couple of Led strip based lighting networks.
The LED's that are about now lumens/m are twice as good as 3 years ago. 10 years ago i switched halogen GU 9 for led GU 9, the cost savings were visible on the electricity bills. I recollect that the new GU 9's paid for themselves in 6 months i think. That was about 4 quid per GU 9, 9/10 years ago. I never found many really good guides on led lighting, lumens https://en.wikipedia.org/wiki/Lumen_(unit), the data is out of date. I bought all leds i use from https://www.lumitronix.com/en_gb/. There product detail sheets are good. I sourced aluminium strips more locally. The rest of it basic electrics you'd learn at school, plus the checking out what MeanWell (probably the most respected supplier of led transformer/driver) can supply. Then balancing.

the disadvantage of led strips/commercial units,
- As noted, the recycling and disposal, they are harder to dispose of.
- Switching strips: Led strips are getting better, so where I used 50cm strip 4 years ago, a 20 cm strip is now same (given price the same, power requirement, and no cooling set up required). So if after 5 years the strip fails and you replace, you'll not be in the market for the most price competitive led strips. I can get 50cm strip with the same lumens output as 5 years ago however:
- The power draw would have dropped, meaning I would have to replace the AC/DC transformer (driver)
- yes you can get the sometimes the original strips for a long time, for direct replacement. But they cost more

Of lesser import, What is the power supply that is being used, 12, 24 or 36V is it direct current or direct voltage. Those are the 3 main standards, I believe 36V(Zhaga) is being favoured more and more. I have used 24V until this year. I wanted to illuminate the garage workshop really well, and discovered that what I can get using 36V was cheaper.

My solution: I made my own lighting fixtures, I made the driver easy to access. I ran 1-5 lights off one driver. I have the feeling the designer architect in your build missed designing in where the fixtures should go. There is frequently no need for luminaires, eg on stairs, halls. In key places I installed luminaires where high powered lighting was required. This is not work of a sparky, just something they need to agree to work with. I live in the Netherlands now, they have developed new standards to address installing DC networks around buildings to address what is happening.
I have had to leave some random and strange access points to drivers. So be it.

If you are seeing that that the sparky has installed on Mains stuff with lower lumens/m that available in say IKEA or Toolstation, then the sparky is not on the ball/ probably playing safe. Also, i get the feeling the they were told we want lights here, here, here and here. Leaving them with little room to maneuver. I am betting too that there are regulations in a vet practice re lighting, so they'd have to stick to them.
For what its worth, in the garage i have attempted IP60/IP61 in the garage. Mainly to assess how complicated sealing joins to fixture on lighting runs would be. I do a lot of wood work, dust gets everywhere.

Ps, I would expect designed in system to be less cost than old style(you have carpenter and sparky costs). luminaires, I suspect are same pricing with Much better energy consumption, and more light.

My biggest gripe with LEDs is trying to replace one of a batch. They have usually been superseded by a 'better' light by the manufacturer, but because of colour variations the old one is impossible to match.

I find at least one of a batch will often fail quite quickly so I make a point of always buying spares if it is not just a one off.