Having just completed a new building in "rural" (Vashon) King County,
let me pass on some hard-earned lessons.  Sorry, this is long, but it
has a bunch of stuff which I hope Google will make visible to people
planning to build in DDES (i.e., Department of Permitting)
areas of King County.

=========================

If you're right at a road with hydrants, you don't need to do additional fire
safety things.  It's hard to be close enough to the road/hydrant.  Now your
choice is to develop fire access (generally, 20 foot wide access driveway
with a turnaround) or install sprinklers.  We chose the latter.  Our
inspector then advised that we should "just" switch to the former, since
our driveway could easily be configured to satisfy the access requirements.

What he didn't tell us (and, if we had ultimately proceeded to litigation, we
would have tried to demonstrate that his actions were informed and malicious)
is that all of that impervious surface will drive you over the threshold into
a drainage review (if your house size hadn't already, which it hadn't in our
case).  And all that impermeable surface will drain somewhere, so you also
get to address that.

In our case, it drained to a second parcel of our place--still our land, but
a distinct parcel.  The DDES engineer reviewing it told us that even an
easement would not address this, but if we "just" merged the parcels,
everything would be fine.  What he didn't tell us (and this was a second
element we would have included in litigation) was that this invalidates your
building permit.  So when you come back from having followed DDES advice, you
will be told that you get to start back at square one and pay for a brand new
permitting process.

When DDES processed our permit, they came back and told us our parcel was
still invalid.  It turns out that DDES keeps a secret file, which you can not
examine, which is parallel to iMap and the assessor parcel database.  They
will not check it during your permit consultation, nor during intake.  But
they *will* check it after they have all the other fees, and it can cost you
some thousands to get it updated.  (Yes, this was another aspect of the
litigation we would have initiated.)

Beyond this, DDES came back again and told us that they had determined that
our whole permitting was wrong, and we needed to come back in to restart our
project.  We would need a civil engineer to do an entire drainage design at a
minimum; he had a list of issues which he would not disclose.  (We ultimately
never laid hands on this list, it was going to be one of the targets of
discovery during litigation.)

It was only at this point that I realized that working "with" DDES was a
losing proposition.  I lawyered up, hired an expert witness in the site plan
and drainage area, and started budgeting for a court case.  This was the
point where DDES behavior changed and, although it took another year, our
project finally was completed.  We didn't need to litigate, although I
did have to spend several more thousands in lawyer fees.

Conclusions from my experience:

Don't build, work with what you have.  DDES makes new construction incredibly
torturous.  Working with what you have will always be easier and more cost
effective.

If you must build, do not depend on DDES directions.  Assume that their
directions may have catastrophic hidden consequences which will double the
cost and time of the project.  Hire an outside consultant.  Treat DDES as
hostile, keep careful records when you interact with them, and e-mail a
summary back to them after each meeting.  Our project became so messed up that
I actually paid to have my lawyer present in each interaction.

Let me note that a pefectly fine contractor will not have the skill set
to deal with DDES.  You need to hire somebody dedicated to this area.
(You can contact me offline if you can't find somebody on your own.)

Budget to litigate.  DDES will tell you right to your face that they can give
you any direction at all, and no matter how bad the advice is, it's on you to
spot the pitfalls--they have no responsibility.  The only way I found to
modify their behavior was to be clearly ready, able, and willing to sue.

Don't build here at all.  If you have flexibility in your home location,
pick a different county.  If I was doing it over again, that is certainly
what we would have done (I'm told that this is the opinion of a large
majority of new construction owners in King County).