Can 'thinking time' be sold as part of a project?

As I sit here finishing up the tail end of a long, intense and fast-paced project, it occurs to me that we really didn't have enough thinking time on it. I mean time to *really* think about design alternatives, think through implications of our design decisions, bounce ideas off third parties etc. The sort of time that bears inspirational fruit. The sort of time that creates 'eureka!' moments. Sigh.

In the end we ended up spending more time documenting our decisions for the client's benefit than really thinking through them. This is such a shame, and a risk to the client and our overall solution. Why can't we sell thinking time? Why can't clients accept that it is a fundamental and necessary component of design? Project plan, Schmoject plan. If a client could sit in on one of our 'war rooms' at work, see the number of post-its, sketches, printouts, and random scribbles etc. on the walls, floor and desks they might realise the value of this sort of thinking time and cough up the cash for it. Maybe.