An easement in English land law is a legal right over someone else’s property – common examples are rights of way and drainage. A quasi-easement as I understand the term is a right in the nature of an easement but exercised over your own property.
Say you own a house which has a front garden: when you walk from the road to the door of your house you are not exercising a right of way over the path but your right as owner of the land to walk where you like on your own property. Your use of the path would constitute a quasi-easement, because you cannot have an easement over your own property.
If you sold the house and garden you would not remain entitled to use the path; you had a quasi-easement to use the path as a result of your ownership of the house and garden, but that would cease on a sale. But say you decided to sell the garden to someone else but retain the house, would you still be entitled to use the path?
When a landowner sells part of their property, they can only continue to exercise rights over the land being sold if these are specifically mentioned (or ‘reserved’) in the transfer. So you would not still be entitled to use the path unless a right of way was reserved for the benefit of the house. While the need for an access to retained land should be fairly obvious, the problem for sellers (and their Conveyancing Solicitors) is that it is often difficult to know what rights need to be reserved.
For instance a homeowner might be totally unaware that surface water from their house drains into a soakaway beneath the rear garden. So if that owner decided to sell part of the garden which included the soakaway then an easement to use it should be reserved, but if the owner does not know about it he would not tell his Conveyancing Solicitor so nothing would be put in the transfer.
To guard against this problem Conveyancing Solicitors acting for sellers should include a provision in the transfer to the effect that the land is sold subject to all quasi-easements, thus ensuring that the seller can continue to use the soakaway in the land he has sold even though it has not been mentioned in the transfer.