John,
Great topic!
I actually proposed something very similar to this a few years ago. It was the result of a project I did in a church planting class at Calvin Seminary. I was inspired by Stedford Sims who was, at that time, planting a church within the (I believe it was) Sherman Street CRC, to minister to the African American community. To be effective at reaching people outside the "upper-middle-class white" culture, the new church plant needed to have African American leadership and be able to function in a way consistent with the culture of the folks they wanted to bring together.
My thought was that the "un-churched" and "de-churched" are also a different "culture" from the "traditional CRC church folk" culture; and that the only way to effectively reach out and enfold them would be to plant a new church. But, why not plant it within an existing CRC church, for the reasons you mentioned?
Unfortunately, my proposal never made it out of committee. I still think it's a great idea.

I would love some feedback on this idea!
First, three observations:
(1) There is a huge initiative right now to church plant in the CRC (and in many mainline denominations).
(2) There are also many churches in the CRC who have been declining and have reached a critical point (the church has been declining through two pastors and/or has been declining for more than five years and/or is facing the decision to close within the next two years). Perhaps these churches missed reaching the rising generation and now have a desire to do so.
(3) One of the biggest challenges in church planting is without a doubt the cost of facility and equipment.
A Modest Proposal
What would it look like to come alongside many declining churches and attempt to nest a new community within their congregation? This was done at Haderwyk Ministries in Holland, MI. Watershed became a church plant within Harderwyk. They ended up becoming three congregations within one campus. Check it out here:
http://www.harderwyk.com/
This could solve the facility/equipment issue if the "nesting church" agrees to allow the planting church free use of the space and the sound equipment.
The key, it seems to me, is that the "nesting church" does not have creative control or any kind of governance over the church plant (this has always been the problem when an older generation starts an informal, 11am service...the people in the 11am service have no power). The church plant has its own elder/deacon board and these people are separate from the "nesting" congregation.
Some questions:
(1) Do most church plants need to start in a different kind of found space (school gym, store front, warehouse, etc.) or can they exist in an older church?
(2) What if people from the "nesting" church want to be on the launch team of the new church plant and/or transfer their membership to it?
Your thoughts?
-John Burden, Providence Church, Holland Michigan
For example, many larger churches have a staff with an associate pastor. Perhaps a classis could identify
dOne of the biggest challenges in church planting, without a doubt, is the cost of facility and equipment
How do we address the issue of churches who have reached a critical point in their life as a congregation (a church has been declining through two pastors and/or for more than five years and/or is facing the decision to close within the next two years)?
There are many churches like this in the CRC. There are, however, many churches who are thriving in the CRC (let's suspend any definition of "thriving" for the moment). Often times they are in the same town and certainly in the same classis. Churches who are clearly declining, who were not (for a variety of reasonsSo here is a modest proposal:
(1) First, identify
In any given classis, there are churches that are both thriving and surviving. Ther