The economics of design do not allow for the time it takes to write a specification and assemble a project manual.
You have to be extraordinarily well-organized to spend less than one hour on each spec section. There are usually about 50-70 architectural spec sections. Say 60 hours to produce the spec. If the specification represents 5% of the architect's fee (which I think is about right), then the math tells us that at somewhere above a $3,000,000 project, it might be feasible. This quickly rises to $4,000.000 or more if you aren't as efficient as my example. Or if your spec writer is better compensated. See my math below. You can quarrel with my numbers, but the point is that bound specs aren't affordable on a lot of projects, even public ones.
The solution for smaller projects is to insert succinct General Requirements into the drawings; and then do one of two things to cover the technical specs
Either solution would basically cover just the materials that are required. The Part 1-General and Part 3-Execution stuff goes in a specification in the General Requirements. This is referred to by every technical spec using a statement like "All Division 1 General Requirements are part of this specification."
Ideally either solution is made part of the drawings to avoid the time and cost to produce the Project Manual. Specs on the drawings also saves the time spent in looking for the project manual to refer to it (which the contractors won't bother with). Everything is in one set of prints. Or nowadays, in one set of PDFs for you to reference from your desktop, laptop, tablet or phone.
I think bound specifications are an artifact of the 20th Century and will be a quaint idea by 2025.
Here is how I implemented this idea.
I think Specification Notes should have a role in every project. By Specification Notes [SpecNotes] I mean a section by section listing of the key requirements of every type of work, arranged by CSI Division and Section Number. The SpecNotes are placed on the drawings. We usually place the General Requirements on a G-series sheet right behind the Cover Sheet. The Architectural Technical Specs are placed on sheet A001, A002 (if needed) per the National CAD Standards. Take a look at the embedded document to download our 30+ page master SpecNotes to start your own.
For small projects where detailed keynotes are adequate, only General Requirements might be in SpecNotes form.
For medium sized projects or small projects that will be competitively bid, you could use Specification Notes in lieu of a Project Manual type of specification. The General Requirements and all the Technical Specifications are part of the SpecNotes. Such brief specs work just fine if you have well-thought-out General Requirements to cover all the usual boiler plate in the General and Execution parts of the typical specification.
For big, important projects, where you can't avoid a Project Manual, you should still place the Specification Notes on the drawings because it is the most effective place for this type of information. The Project Manual is where you place all the Part 1: General and Part 3: Execution boiler plate in traditional style. But since you can rely on your Specification Notes for the Part 2: Products section of the specs, there will be a lot less editing required. In fact about 80% to 90% of the technical specs can be standard documents requiring no editing if you make liberal use of the phrase "(if any)".
If BIM ever gets around to addressing the "Information" part of the concept, you won't be using Project Manuals any more. So think of this as getting a head start.