Whats the easier way to frame out the walls with 2x4's? Build them in place or build sections on the ground and lift up into place? My floor and ceiling joists are pretty level. Thanks.

Hi guys. I am new here but hoping you can help me. My house was built in 1971. I am the second owner. There was an addition put in on the other side of a wall that you will see pictured in my basement. Behind my furnace, there is a large hole in the cement wall that has been covered with insulation. Behind this hole is the old foundation and a crawl space under my current house's addition. The hole does not expose the basement to the elements, but it allows cold air to pass through and potentially rodents. The basement does indeed have some humidity and I have to run a dehumidifier in all seasons. I had thought about dry-lok'ing the walls in my basement but there is not enough proven research that this will indeed reduce humidity. The previous owner instructed me that this hole was created when installing duct-work and piping for the furnace and he just "covered it with insulation". Would anyone advise if I need to re-cement this large hole in the wall to keep the house heating efficiently? Does a hole like this belong in a foundation? Doesn't seem correct to me but I am fairly new to home ownership. I think posting pictures must be rocket science here so I added a picture below at the URL, but the picture turned out sideways. I apologize. [URL="http://s16.postimg.org/gvklanls5/basementwall2.jpg"]http://s16.postimg.org/gvklanls5/basementwall2.jpg [/URL] [ATTACH]61188[/ATTACH] [COLOR=#000080]moderator note: pictures are limited to 600x600 and 50kb file size[/COLOR]