We had an offer accepted on a property and are nearly at completion. Searches didn't show up anything but on further investigation the land directly behind is going to be sold for development next year. This in itself is not a problem but it has since come to light that the property we are buying is encroaching on this land. At some point the present owners have attached their fence panels to the metal security fence surrounding the land, also the large shed &'pergola are also secured to the fence. At some point this fence will be removed which will impact on the garden. We estimate it will cost £2-3k to replace the fence and restore the garden. We've asked for a contribution from the sellers of £1-1.5k but they've refused. Their estate agent has sent us a long email which is, in our view, unprofessional, trying to push us into exchanging before we're ready. Initially the sellers told us they were not buying immediately and therefore there was no chain. Suddenly they are saying they need to complete asap or they will lose a property. Are we being petty over the fence or is our request unreasonable?