You think it’s OK to remove a hollow-sounding wall

Just because your neighbours did it, or just because you tapped it and it sounded hollow, it doesn’t mean it’s safe to remove an internal wall. What you can’t see or hear is a structural element that could be bearing the load from the floor above.

Do bear in mind that when you ask a structural engineer to check if a wall is load bearing or not, they will require you to expose a portion so that they can check for the presence or absence of beams. That means you will need to remove plaster from the top of the wall. Yes, it will look unsightly, but a lot less so than the rubble from a potential collapse.

Your builder isn’t sure what size beams you need

That doesn’t mean your builder lacks knowledge. It means they are aware that one size doesn’t fit all and that a structural engineer has to make precise calculations regarding the size and material of a structural beam.

You’re buying a property

A structural engineer will report on areas of concern that may have been raised by your mortgage provider. Their report will include recommendations for remedial work which has implications for your decision to buy and for the mortgage company’s decision to lend.

That crack seems to be getting longer

It could just be superficial in which case you should take your own monthly measurement (length and width). Sometimes cracking appears after alterations have been made to your property. But cracks can also be indicative of other structural issues that need to be looked at, in which case you would be advised to consult a structural engineer. Do be aware that photos of cracks, while useful for engineers, won’t tell us what any underlying issues are.

Damp is an issue

Bear in mind that not all structural engineers are damp specialists. They may be able to check if damp has affected the structure of your property, but they cannot verify the causes and treatment of damp unless they are trained to do so. A qualified damp surveyor should have a CSRT (Certificate in Remedial Treatment) or a CRDS (Certificate in Remedial Damp Surveying).

Your neighbours removed their chimney breasts and they didn’t need a structural engineer

Actually, they did. They’re very lucky the support they put in place has prevented other chimney breasts in their property from collapsing. There is no getting out of it: you need a structural engineer to design all necessary support elements. You also need to ensure compliance with your local Building Control Body – this is something your engineer will be able to provide.