I'm afraid it's not a straightforward answer to this one, without all the facts.
There is clear separation between what the architect has provided, and what the builder
was asked to do.
Put like this:
Architect provides drawings for construction:
- These are incorrect, proven to be wrong, and the Architect is negligent. fact
Builder asked to price JUST the drawings:
- He has done all that is asked, the architects drawings are wrong, the additional costs incurred
by you would be your claim against the architect.
Builder asked to price the job BASED on the architects drawings:
- An experienced builder would be expected to price the work, based on the drawings and the
current site conditions. The architect is still at fault, and so is the builder.
I work for a large building contractor, had the architects plans been incorrect, and i was asked
to price the work as per the plans, i would be claiming for additional costs to put it right from the
client.
The client, in turn, would then claim against the architect.
All too easily the architects get away with it. I would write them a letter, citing the fact their drawings
were incorrect, stating the additional costs you have incurred, and await their response.
If the response is unsatisfactory, write again, and copy in the RIBA. They should be members
of RIBA. They will take a dim view on architects drawings being incorrect. Ensure you request
that the Architects put their 'P.I. insurance on risk'.
http://www.architecture.com/ (RIBA)
They often state that all dimensions to be checked on site, by the contractor, however, £1500.00
on a domestic roof is an unreasonable error!
However, as mentioned above, check EXACTLY what you have asked each party to do; Any party
can only do what has been asked, and can only get it wrong when they deviate from this.
Often, the architect sources builders, and 'project manages' these domestic jobs. If this is the case
then you only have one place to go, and that's the architect, and how he has procured the work.
If you want any assistance, let me know....