Hi it seems I'm in a similar situation with my conservatory base, I've got a local conservatory company to take old conservatory down and replace with a larger one.I explained I wanted the old base taken up as I didn't know how it was put down and whether it had any insulation after reading some of the replies I am a little concerned to say the least. The base construction has been subcontracted out to a local builder first of all the footing have not gone down 600mm and not 450mm wide the footing come up to in parts level with the patio an then the first course of bricks were laid which now after reading conservatorysurveyor reply this is wrong. 2nd airbricks there were 3, two of which were under the old base which had a small like drainpipe from house under base and onto the airbricks at the front of the old conservatory wall well this builder has cut the old pipe to about a 2ft length and chiseled out one of the air bricks from the house and cut in half and put the two halves one on each side of the new wall also the small pipe runs slightly downwards towards the house so if water gets in it will run into the void under the living room, when confronted with this he said it doesn't matter it only being half air brick on each side as the pipe is only small I couldn't believe what he said. I saw the conservatory company yesterday and coming round tomorrow morning to see for himself there is going to be more problems I can see because I don't think he intends to put insulation down before he concretes the floor as after reading this forum he doesn't seem to have enough space for insulation and the screening and why has he got the DPC on two levels the outside at brick 3 and the inside brick wall at 2. Any help would be much appreciated thanks Joe