The lintel is 28cm deep.

Hi

You sound very worried about this but to me that looks pretty bog standard where the house has been extended and unless I am missing something, as far as the 'look' is concerned it will look absolutely fine when the work is finished. Be prepared for it to look worse though when it is newly plastered and the room becomes darker until the plaster dries. 280mm deep is covering a hefty lintel and obviously that cannot be changed so I think you now need to go back to your kitchen planner and ask them to tweak your plans to accommodate the beam.

I am writing this to reassure you more than anything, you sound so worried. It will look fab when when it's finished, honestly.

I have the same lintel in my kitchen where we joined the utility with the original kitchen and it’s fine.

I don’t have tall units around it as mine goes over the island with the hob in.

Standard tall larder units are 1970mm high so they would fit unless you’ve opted for the extra tall and in which case swap them.

If the space under the lintel is only 200cm [2000mm and total ceiling height is 2280] then i'm afraid that is low. Unfortunately the information Daisy has stated is incorrect in that she hasn't included the plinth which for a kitchen is [usually] 150mm so for a medium height tower unit the total is 2120mm. Depending on where you're getting your kitchen from there are short towers available at 1975mm including plinth, made up of a 570 and 1245 tall doors, then if your other towers are taller i'd just infill to match the other tower heights [infill scribed around lintel]. As Jo says, speak to your designer as they will need to redesign part of your kitchen. Without seeing the proposed plan/design its a bit difficult to advise further.

Lifestyle, yes my error. Didn’t take the plinth into consideration.
Depending on where you get your carcases from, some suppliers offer made to measure sizes. Then of course you will also need made to measure doors which again are offered by some suppliers. If the ‘odd size’ is in the middle of a run of tall units then you would need to consider what style of door if you have a non standard tall unit. Having doors that don’t line up are not aesthetically pleasing.