Expert: Dan Griffin - 10/2/2009

Question
hi dan
we have an existing gruond floor kitchen and lounge extension,but we want to extend up to the bedrooms and loft. the original extension was built about 15 years ago.i dont have original plans. i have been told that i will have to show the footings and with the extension having concrete floors i will have to rip them up and insulate. this is putting me off already,can you clarify please.cheers

Answer
Steve, to add a second story on an existing footing will require knowing if the original footing was designed and executed with enough material to hold the additional load.  YOu may have a local energy code that requires the insulation.

A local structural engineer will be able to diagnose the footing.  This may require digging completely under the existing footing at one or more points to verify the insitu condition.  This information coupled with the additional load requirement and the bearing capacity of the soil will answer the loading question.  I would be surprised if the present footing would not be fine.

I would think, if the existing footing was sufficient that the footing would comply through grandfathering for the new addition.  This answer can only be answered by your AHJ - local code enforcement.

I certainly hope this makes you more knowledgeable and that you are able to continue with your extension plan.