Porter Davis Site Costs

Hi All,

I've been lurking around this excellent forum for a while now, and I've learnt lots of great things, and I read some stories that have scared the crap out of me!

Thanks to everyone - expecially the building and construction professionals who take the time to help out the inexperienced.

In a couple of weeks we will be heading into a tender meeting with Porter Davis, and I'd like to be as prepared as possible - hence the reason for the post.

We are buying some land in the Geelong (Vic) area.

We have paid out $600 deposit and the soil test was arranged by PD with "Structural Works". After I'd seen that the core holes have been drilled on out block, I phoned PD to ask about the results of the test. I was told that the site was classed as "P". I asked for a copy of the report, and they agreed to fax me a copy.

The report indeed says P class, but says this is to "account for the abnormal moisture conditions caused by trees on this site and adjacent sites, as per AS 2870-1996."

The report goes on the say:

"A minimum slab freeboard of 150mm is recommended"

"A waffle footing system suitable ot an "M" site reactivity (310mm overall depth 225mm boxes, 85mm slab) may be appropriate for an articulated brick veneer dwelling. Refer AS-2870 1996 Fig 3.4. On fill side, where the depth of rolled compacted fill exceeds 300mm, the waffle footing system shall be supported on piers founded into firm natural B Horizon CLAY as noted in borelogs"

There's a fall on the block over the site of the house of approx 1 metre (I measured it), and as a result we allowed $15k for the site costs, before the soil report came back.

I'm interested in opinions of people who have had a similar soil report come back, or professionals who know about these things...

1. Would removal of the trees make an difference to the classification of the soil?

2. In the recommendation above, it sounds like "supported on piers" is the use of screw piles, similar to some of the other people on the forum who are using Porter Davis. Is that the case? My feeling is that whenever a soil report suggest screw piles, the site costs head higher than you can jump over.

3. Has anyone building with Porter Davis been able to organise their own earthworks? I have a feeling that removal of trees and cut-and-fill with a small retaining wall is going to be charged by PD at an outrageous amount - like everything they do.

There's a picture of the site on our blog... it's a work in progress.

http://www.perryr.com/homeblog/index.html

Thanks for reading!
Perry