Cost estimation without structure plan ?

[sholla]

Hi,

I kindly request forum members to throw some light on my
situation.

I am preparing to build a stilt+2 Floors duplex house in a 30x40 plot.
Stilt will be two feet below the road level and five feet above.
Architect indicated that we should go for the labor+materials contract
for the civil construction and then separate labor contract for
electrical, sanitary and interiors.

We finalised the working plan with the architect and expected
that the structural plan will be completed next so that some quotations
for the civil construction can be requested. Architect is saying that
the structural plan is not so important for the purpose of quotation because
for a 30x40 consturctions, contractors will assume a standard configuration
and quote. Their margins will be very adequate to take care of all conditions.

Initially he said the soil testing is not required because he had done a similar
project near-by. But now saying that soil testing is required and so arranged
to dig two pits for this purpose. We are now finding that in the front pit
there are rocks at 1.5 feet depth and in the backside pit the rocks are at
one feet depth. So pit digging was stopped and soil testing was not done.
It is at this point that he said we can ask for quotes without soil testing.

My view was that we should complete the plans (working + structural)
before going further. So he is now saying we sould dig out 2 feet depth
from the plot, find out the type of rock (soft/hard) and then decide.
He is asking some person he knows to do this, possibly using JCB etc.,

Now that rains are occurring I am worried about this process. what if
there is considerable gap between the soil clearing and the actual civil
construction start ? Is this the right way to go forward ?

Regards
sholla

[mohanvk]

Dear Sholla,
Would like to introduce ourselves as experienced architects and engineers, doing turnkey construction and I have been also involved as a consultant for high rise structures in Bangalore. You wold be well advised not to rush into the process without considering the following:
* You have not mentioned the location of your site, but in many cases, when rock occurs in the strata it is usually followed by water and a high water table which would may not be conducive for a lower foundation like you are planning, specially when you seem to have hit rock at just 1 feet. However, this needs to be properly investigated if this is hard rock or disentgrated rock as in the latter case the same can still be mechanically excavated. Please be wary that if there is hard rock, trying to go for a foundation with a basement level below the road could increase your costs considerably.
* Yes, having a soil test done would be the right way to handle things as the bore holes will give a fairly good idea of the soil strata.
* Normally in Bangalore we are able to go ahead with foundations for individual houses without too many problems though the progress could be slowed down.
* A budgetary estimate can very well be prepared on certain assumptions with regard to the structure, but a more accurate item rate quote should be insisted on to form the basis of a 'per sft' contract so that any variations in designs/finishes/client issue material can be easily adjusted. Just going for a lumpsum contract on a sft contract without any BOQ can result in a mess later on as it is unclear what the contract covers in many cases. Please insist on basic rates of materials, or if the same is not given, then be clear whether you are going to have an escalation clause or not.
Do get in touch with us if you require further info.

[sholla]

Hi Mohan,

Thanks for the reply. I want to clarify that the proposed construction is column-based.

Architect was saying that in a 30x40 site excavating the site fully is same as digging
separately for the 12 or so footings.

Secondly do we need to do a full site 2-feet excavation (at Rs.6 per cfd) now to understand
type and placment of the rocks in the site ?

Or should we make this part of the overall contract itself ?

regards
sholla

[mohanvk]

Having 12 columns for a 30x40 site may not be very efficient design. You can review the design and try to eliminate a few if possible.
Even so, and assuming if each footing is an average 4'x4', the footprint of the columns would be 192 sft against the site area of 1200 sft, so definitely excavating only footings is cheaper than the whole site.
YOu do not require to do the full excavation to test the soil conditions. Any testing agency can do an augur bore sampling for atleast two locations at the site to determine this.
It does make sense to make this part of the design fee itself, and the architect can add it in his bill.
Regards
Mohan

[alamzartab786]

[quote="sholla"]Hi,
Sir, You should go for turnkey solution. I have a good experience with xxxxxxx of companies for same kind of work. you may contact xxxxxxxxedited by admin