Some people talk about the institutional church as opposed to the organic (relationship driven) church. I don’t think the distinction is fair. The language usually frames churches with over 30 people and a complex structure as institutional and inferior.
Most local churches with buildings and staff are not completely driven by structure and programs. There are organic elements in very large highly structured churches. Conversely most house churches have some structure and some layers of complexity. In short “institutional” churches have organic elements, and “organic” churches have institutional elements.
I don’t think the question is whether your church is an institution or not. The question is what type of institution are you. There are a number of different types of church structures like congregational and episcopal. I’ve started using those labels more because they are accurate, and don’t imply anything negative.
It doesn’t take long when you lead a house church to realize that getting rid of some structure can help. This is particularly true when dealing with certain kinds of people. It also doesn’t take long to realize that what you’ve changed is only a fraction of the whole situation. The bulk of church life and church leadership is still dealing with the same old issues that have existed for thousands of years.