Do you mean 20mm rather than 200mm? I suppose where you *could* notice it would be around the full length doors, so that is something to consider. Doors would also have to be shortened and skirtings raised.

Are you renovating to sell it? In that case would you be able to recoup the cost of the work back on the value of the property?

If it is your place to live in, then I could understand but you do need to consider it is a hard job to get those tiles up and to level that floor. If you are laying wood the floor would need to be flat so all old adhesive needs to be removed, not an easy task. I would guess replacing with tiles would be less work as new tile adhesive would allow for minor variations in the floor. There is also the point that you don't know what you will find once you pull up the tiles - you could be find yourself getting even bigger labour costs for the job. Have you tried removing a tile to see how it goes?

Thank you, yeah I do mean 20mm,
The builder has assured me he can raise the level of the bedrooms and bathrooms to the same height
(And the front door threshold)
I have pulled up one of the tiles and these does seem to be a level floor underneath (the one we pulled up anyway ) there is hard foam and underfloor heating that won’t work when we lay the floor over the tiles

The flat is for me to live in, the skirting is being raised on top of the new floor and all the full height doors will be shaved

The heating is the crux of the matter then, not the flooring.

Presumably you have no other form of heat. Therefore, although the builder is right you can lay just lay over the top, the answer is, NO you shouldn't because you will cut off the heat source.

Unless you were going to the trouble of installing electric heaters on the wall everywhere, the floor should actually come up.

You didn't mention the heating problem in the original post.

My advice with the new info is to take up the original floor and lay new, then you can still use the heating.

Are the tiles so bad that you can't just keep them and use rugs?

I am getting wall heaters installed

Good morning,
I have to say I agree with Man About The House.
If I understand it correctly:
You are proposing to put down a new floor over the existing, which will dramatically reduce the effect of your existing heating system, then to counter act that you will introduce and pay additionally for a secondary less efficient source.
all this to save £1500 (less the cost of materials and labour of the new heating system).
Take it that the advice we are giving you is to benifit you only and is not dictated by the work involved in removing the tiles.

I wish you well with your project.

I’m not keeping the under floor heating whatever happens that is now obsolete

Have u thought about getting a very large jute rug which is bang on trend and will allow your floor heating to work and save all that hassle?