Subdivision Regulations

A client of mine is having issues with older platted subdivisions and more current infrastructure requirements. I'm looking for someone who can give me some ideas of how to handle these older subdivisions that have no existing requirement for infrastructure but lots are being sold anyway. To complicate this, there are those lots that can affordably gain access to streets and water (corner lots usually) which leads to sparse development.

Since we are in Texas, I'd like to hear from other Texas cities to see how they've handled this situation; however, I will be grateful for any feedback from anywhere.

Thanks,
Audra