Thanks Mike for your reply which I only saw just now.
The points you raised and my further discussions have lead me to conclude that we will have to use an architect after all.
It seems in your case, you had used architects for design etc but then had separate contracts with the builders. When speaking to architects I was almost under the impression that they would take responsibility for the whole project. Is this common or is it more usual to engage builders and architects separately?
Our apartment is on the top floor and all the walls we want to remove are “tabique” but as you said they may still carry some load after been in place since the building was raised.
Thanks again for your help.