knocking through a previously bricked up door and reinstating old dividing wall

[BasinHaircut]

In our new house we want to re-separate the 2 reception rooms. Several owners ago the room was knocked into one and one of the doorways was bricked up.

Can we knock the doorway back through ourselves? and will there be any structural issue with this? Im assuming that original support for the doorway will still be in place (would there have been any reason to remove it?) and if we start chipping the plaster off we will be able to locate where the door was and just knock through the 'new' bricks? I can already tell roughly where the doorway was by knocking on the wall.

Secondly, when we re-instate the wall, I want it to be solid and soundproof. Can we re-instate a brick/breeze block wall rather than a stud-work and plasterboard one? Ive only ever had first floor walls done before and we used plasterboard. Even with insulation in them I found that you could hear everything from the next room and I don't want that. Also, will it be much more complicated/expensive?

I have had to do both, my old doorway was breeze blocked up so once plaster was removed it was easy to track the doorway and reinstate. The wall we used breeze blocks and was plastered both done by a general builder.

thanks for responding Time. Yeah will probably get a builder to do it to be honest, I like the idea of doing the knocking down myself but id probably cause more damage than it would be worth!

We also need an unsupporting chimney breast knocked out which I have no intention of tackling as I remember when my friends did it and the soot was awful!

We live in a Victorian house and had a food bricked up last year as we were knocking through to make it open plan at the back. Interestingly the lintel was wood and i think the builder removed it (see photo), so you may need a new lintel if your house is Victorian. Interestingly the whole of the back of the house was also held up by a wooden lintel

*door not food!

Thanks marmite, not Victorian, we are 1930's but definately worth checking obviously!