Building consumption not affected by district surplus: bug?

[Urelias]

Example
If you build a building that consumes 50 heat in a district that has 100 heat more than it needs, fuel will still get deducted to generate 50 extra heat.This is despite the district showing the -50 from the building and the +X totalling to a net of 0 heat needed for the district.

Question
Is it intended that you always have to pay this price directly and not through eg. heating hubs?
If so, the heat demand should not be included in the total of said district since it cannot be affected by anything.

Impact on city economy
In my case this possible bug results in a great loss in efficiency:
My New London at week 240 should only consume 180-ish coal due to adjacencies and heating hubs when integrating building cost in districts.
The total fuel cost however lies at 550 due to the buildings not benefiting from good city planning.

Is this something known?

[Nestortillo]

Same doubt here!!

[MetalHev]

I'm pretty sure buildings are bugged, some other adjacency bonuses also don't work (workforce, efficiency) while other works fine (materials).

[Landlocked]

As far as I can tell, buildings don't have their heat reduced; only districts. The heat bonus calculation screen is bugged and will show building heat reduction if you have enough bonuses, but that won't be reflected in the fuel consumption. To test, start with a district that has a building with about 60 in heat bonuses. Reduce the district with to 1/5 capacity and toggle the building off and on while watching fuel consumption.