It is not unknown for restrictive covenants to ban, for example, the keeping of dogs at a property, though the more restrictive covenants you put on a plot, the more they affects the price you will receive. As a rule of thumb, developers expect to pay one third of the value of the finished development for the plot. So, if a £150,000 house can be squeezed into your back garden, you should think in terms of receiving £50,000.
Your buyer profile can depend on what type of property you are selling, whether the land has been developed already, its location and market conditions, among other criteria. Is your likely buyer an individual looking for a lot for a new home? Or is your buyer going to be a builder or developer looking for land for their next project? Or is your buyer some combination of those, or someone different altogether? There may be different buyers for finished lots, rural acreage or a parcel of suburban land in a thriving new home market.