1) for the record, developers do not build houses (typically). Home builders build houses. Developers build streets and install sewer lines.
2) Keep in mind that property that goes up for development is typically on the open market. People who protest development usually have the option of placing the property under contract and buying it themselves. You cannot blame a private land owner for excersizing his right to sell his land. If you don't want to see development, put your money where your mouth is and buy it yourself. The best way to preserve land is to buy it and do nothing with it.
3) Urban sprawl. I am 100% against urban sprawl. Reality is though that developers and builders provide a service that is demanded by the people/market. Trust me, developers and builders would not do what they do if they could not sell their product. Supply and demand dictate that developers develop and builders build. Please keep in mind that you would not, unless you are the rare case that built your own home and installed your own street, you would not be sitting in a house with electricity and be warm and dry if it were not for a developer and a builder. What if your home was firebombed by people that thought the tearing down of the land you now live on was the best thing to do since the forest was torn down to build your home? The hypocracy of the eco-terrorism people and their supporters is ridiculous. Think it through people...who the heck built your house and who the heck built your street?
4) If you truly are against urban sprawl, and I suspect everyone is and I think we all should be to some degree, I encourage you to get off your rear end and get involved in your local land planning. Most places have zoning departments that oversee land use. I encourage you to look into better land use concepts.
I am 100% for high, high density. Creating large lot zoning, by it's absolute design, magnifies and increases urban sprawl. Doing the opposite, creating areas of high density and combining it with green space does a much better job of accomplishing what you are talking about. Unfortunately, people somehow think that density is the culprit and that larger lots is the way to discourage building and nothing could be further from the truth. I am a strong believer in creating zones of high density, say 12-14 units per acre, in the approrpiate areas. The catch 22 is that we live in a free country and the reality is that land owners will all, or at least most, will cash in on the financial investment they have made. Developers pay the big bucks that these land owners want. Unless states or conservation organizations come up with a way to get the landowners the money they want it will go to the highest bidder. Creating development easements whereby the development rights are assigned to a trust is about the only way you are going to stop the development. Most land owners that place their large tracts into a conservation designation for taxation purposes do it as a cheap way to hold a long term investment for it's invetible sale to the highest price the open market will allow.
As well, creating and mandating large lot zoning actually makes the gift and dream of homeownership beyond the realm of affordability of most people. You would then create a situation where most people could no longer afford to purchase affordable housing, which leads to many unpleasant results as there is no better way to create a healthy and safe community than to have a high percentage of homeownership. How are you going to assure that you have affordable housing if you enact legislation that requires 5 acre minimums? That $150,000 house just became a $400,000 or more. What do you do with people that own land that is less than 5 acres in size? What if someone just bought a 3 acre tract? What if you own a 1/2 acre tract? I say go the opposite direction and the results will be more what you actually seek (i.e. greenspace)...high density all the way!! Even if you do the typical subdivision and not a new ubanism development (http://www.cnu.org/about/index.cfm), at least create conservation subdivision ordinances whereby you can build the same # of units allowed by a typical zoning designation but then clump them together on smaller lots and leave the bulk of the property untouched. Everyone wins...the developer has less dirt to move and pipe to lay so it is cheaper, and the area retains open/wild lands from then on as it is in a platted subdivision and deeded to the HOA and covenants restict it's sale.
I am a big believer in new urbanistic development and I encourage everyone here to look into it...make the density high, the lots small, the homes tasteful, and create even more land in the public realm for all to enjoy. Density is not the enemy the public often perceives it to be, if density is developed properly.
We as a culture need to find, for many different reasons on many different levels, a different way to live than the cul-de-sac subdivision environment we have created and bought into. It is an unnatural way to live. A new urbanism approach to development actually gets us going back to a more natural way to live, a healthier way to live.
Ok, off my soap box now. Sorry to be so long winded- I spend a lot of time in my work dealing with these types of issues and welcome anyones comments on any of the above.