ᐅ Widening Door Openings in Older Buildings to Meet DIN Standards

In our old building currently undergoing renovation, some doors have unusual dimensions, for example, a rough width of 84cm (33 inches).
Since this is close to the DIN standard, I would like to adjust the width accordingly to avoid having custom-sized new doors made. I plan to cut the masonry at the desired spot using an angle grinder and then chip away the 4cm (1.5 inches). Is this approach feasible? Any tips? What special considerations are there for doors located in load-bearing walls?
Best regards,
N

Nanopixel schrieb:

I would cut into the masonry at the desired spot with an angle grinder and chisel out the 4cm (1.6 inches) accordingly. Is that feasible? Any tips for this? Are there special considerations for doors in load-bearing walls?

Consult a professional.
You can’t just chisel away something that supports the lintel. Maybe it’s wide enough, but we can’t answer that from here.

For this, you need to consult a professional. No one here knows your house, your walls, or your door lintels! Narrowing is certainly not an issue, but widening definitely is. This cannot be decided just by guesswork.

In general, 2 cm (1 inch) on each side should not be an issue. Especially with load-bearing walls (there is often only one), you should expose the lintel. After widening, it should have a minimum bearing length of 12 cm (5 inches) on both sides. For non-load-bearing walls, this is usually less critical. However, consulting a structural engineer is generally a good idea. And/or you could upload some photos.

Should this necessarily be distributed as 2cm (0.8 inches) on both sides for balance? Possibly, applying 4cm (1.6 inches) on one side might better suit the room layout (and would also be less work).