It's all software under the hood, they'll figure it out.

Architect draws out the plans on the software, which automatically deconstructs it into a project plan and various individual components which the robots already know how to build.

Then you set them loose and they just build it. "Them" being an army of machines each with their own specialisation.

It will change architecture as much as it will change for architecture. The software will have a menu of different features to insert into the drawing - features which the machines know how to build. Features outside of this will be flagged on the drawing as requiring manual intervention to complete.

Because these manual interventions will slow down the build and will require checking before the machines can come back in, this will influence the decision-making process. Over time, as the software evolves, architects will have more freedom to make embellishments that the machines can figure out on their own. But for a period of time, there'll be a churn of somewhat samey buildings all (over)using the same templates. In some cases you'll have buildings which are architecturally odd or spatially inefficient, but faster and cheaper to build.

Your question about carpenters is kind of moot. How do we train welders if robots are doing all the grunt work?

The answer is that there will virtually always be a requirement for specialist, artisan or one-off pieces. No small contractor is going roll up in their van with a Boston robot to install a TV cabinet or put together your IKEA furniture.

But they might have one that they use to build walls or help them put in a kitchen.