Hi! Now it's time for the living room, but not a single wall is straight! Which one should I start with to get a "straight" room? When I cross-measure the floor, it differs by 14 cm. Additionally, all the walls bulge from top to bottom. The walls would need to be plumb straight before I start horizontally, but that's not possible. Am I thinking wrong? Where do I start? Are there any new construction tools that can help, like a laser?[/font]
If it's important, then it might be necessary to build new interior walls, but rooms and walls not being straight is probably more standard than the exception. 14 cm in how large a room?
Well, we're going to build new interior walls. I mean, set up on the old ones. That's where I don't know how to start to get it right... The room is about 25 square meters. 14 cm difference on the cross measurement, meaning the diagonal's difference from the other.
Do not attach the studs against the old but rather standalone walls so you decide what is straight. Just keep in mind that it's not sensible to insulate or build too much on the inside.
I had similar issues when I bought my house. The walls are made of brick, and over the years the plaster had become very uneven.
I solved it by first marking where the "hollows" were by taking a board along the wall to see where there were gaps. Then I filled the gaps with plaster.
Once everything dried, I glued new drywall in place using plaster as adhesive, just pressing it on without screws, and in a day it had dried properly.
This doesn't solve your diagonal issue, but the question is whether a 14 cm difference is noticeable in 25 sqm. I've even lived in an apartment where a partition wall was intentionally placed at an angle, so all rooms in the apartment were skewed. In the living room, there was surely a 50 cm difference in width between the two short sides, but the long sides were the same length (if anyone understands what I mean?)
I solved it by first marking where the "hollows" were by taking a board along the wall to see where there were gaps. Then I filled the gaps with plaster.
Once everything dried, I glued new drywall in place using plaster as adhesive, just pressing it on without screws, and in a day it had dried properly.
This doesn't solve your diagonal issue, but the question is whether a 14 cm difference is noticeable in 25 sqm. I've even lived in an apartment where a partition wall was intentionally placed at an angle, so all rooms in the apartment were skewed. In the living room, there was surely a 50 cm difference in width between the two short sides, but the long sides were the same length (if anyone understands what I mean?)
A comment to Snuttjulle. Why wouldn't it be sensible to insulate on the inside? I would say it's an excellent way to add insulation. Additionally, it allows for new electrical installations and outlets. The only reason to be cautious with internal insulation is if there's a vapor barrier in the wall? Then maybe you should contact an expert. But a simple rule is that the vapor barrier can be located 1/3 into the wall's construction without the risk of condensation on the "wrong" side of the plastic. Now, we don't know if it's a new or old house, but since the walls are bulging, maybe it's timber, and then in all likelihood, there's no vapor barrier in the wall. However, one should ensure that ventilation isn't compromised with a tighter wall. In a living room, there should be incoming air, and of course, that must be arranged somehow.
I wrote "not too much" and that means adding so much insulation that any vapor barrier ends up in the wrong place. 
The recommendation is always to insulate on the cold side from what I have read.
The recommendation is always to insulate on the cold side from what I have read.Hello again!
We've been measuring and measuring, cross-measuring, and running around with the laser for several days, so now we're satisfied... I think. At least we've managed to get a perfect square for the floor! ;D The problem, however, is that one window won't be straight and unfortunately, the exterior is already fixed. And in addition, the lady of the house wanted the ceiling preserved (the only nice thing in the whole house!) but now it's going to look very crooked as it consists of grooved panels in different square sizes. I guess I'll have to try to appease her with something
It's a log house and the insulation question isn't a problem. It'll just be a five on the inside. Possibly with sporadic voids...
We've been measuring and measuring, cross-measuring, and running around with the laser for several days, so now we're satisfied... I think. At least we've managed to get a perfect square for the floor! ;D The problem, however, is that one window won't be straight and unfortunately, the exterior is already fixed. And in addition, the lady of the house wanted the ceiling preserved (the only nice thing in the whole house!) but now it's going to look very crooked as it consists of grooved panels in different square sizes. I guess I'll have to try to appease her with something
It's a log house and the insulation question isn't a problem. It'll just be a five on the inside. Possibly with sporadic voids...