We're building with PD and they provide R2.5 insulation to ceilings. I've been advised to increase this.
How do you do this? What is the best way? Just ask the builder what options are available?
What's a good rating to increase to? And how do they do it?
Would it be best to go thru the builder and get them to do it during construction, or do it after and get someone else to do it?