It is important to carefully read the instructions included with the AIA A105 agreement form. For instance, the instructions explain that to shorten the document dispute resolution by arbitration was omitted and should be added if it is desired.

A105 is similar to many other AIA agreements but it is not at all standard in the construction industry. The differences are too many to mention here but for instance:
-What is commonly called a "warranty" is different in an AIA contract. Under Article 14 the contractor's obligation to correct defective work continues for 1 year after completion.
-In a contractor written house building contract there is rarely any mention of the owner's right to carry out the work nor is termination of the contract.
- A105 provides for an architect to oversee the project. Will you have one or will you strike all references to an architect in the agreement form?

The detail you mentioned would usually be in the design drawings rather than in the technical specifications simply because it would be a better indication of where the material is located and would be more likely to be noticed by the contractor. It is sometimes a good idea to include full sized sections of all trim and molding with notes about where they should be used.

If you are not familiar with construction contracts you should ask an architect or a lawyer to assist you.

This is more of a general answer rather than a specific one, but I think Renovator8 did a good job with specifics. We are more than half-way through our build and really wish that we had done more foot work on our own ahead of time and spelled out what we specifically wanted. For example, I told the GC at least 10 times that I wanted carriage doors on the garage. Last week he asked me if I had picked out my door, when I told him which ones I wanted, they weren't in my budget. If I had researched their prices ahead of time, I would have known that the amount allowed in my budget for garage doors was not enough for carriage doors.

This has happened for quite a few things in my budget. The GC knew what my husband was willing to pay for the final product so my allowences don't fit the specific higher end things that I liked and showed him. Not enough research done on our end ahead of time. Our house will be beautiful when it is done, but I am disappointed that my decisions have been so controlled by budget issues rather than by what I like.

It is the responsibility of the contractor to price what the owner asks for even in an allowance. You are the victim of an unfortunate tactic to make owners think they will be able to build the house they want. The only defense is to refuse to accept allowances and specify something that can be changed later. It's not so hard to do.