In its heyday Oxted Place had six greenhouses all heated in the winter by coal fired boilers. These photos show the remains of the smallest and most remote greenhouse from the house.
The boiler rooms for the greenhouses were all sunk below ground to enable circulation by convection of the water in the heating pipes. Carting the coal up to this greenhouse, which is far removed from any paved path, must have been a trying task.
A similar arrangement was also used to heat the main house until the 1990s with originally a coal boiler, later oil fired in the cellar. While a convection system does not require a circulation pump it does need relatively large diameter pipes of three inches or more to enable the water to flow. Installing these large pipes into the house back in Victorian times caused a fair bit of disturbance to the fabric and the pipework was very noticeable. In the greenhouses, which were built around the heating system, this was less of a problem.
Some years ago on a visit to the Lost Gardens of Heligan in Cornwall we learnt of the history of their many glasshouses which were found in a very similar condition to this one. They have since been lovingly restored to productive use. A project for us in the future perhaps?