Let's start with a definition:

A property portfolio is two or more investment properties.

If you have just one, it's unlikely to be making you a living, and it's unlikely to be taking up much of your time. If you have two, or three, or four, then you already have a small portfolio, and that is likely to be more of a commitment.

Building a property portfolio - either from scratch, or from where you're at now, whether that be a single buy-to-let property or a handful of investments is the ambition we are concerned with here.

To what extent you build a portfolio is really limited only by your own time, energy and resources. Five properties might be your goal, or you might be looking for a £5 million portfolio, the basic techniques are the same.