These are the 'two wee hooses'. They're both glasshouses that anyone might have in their back garden and are used to run comparison observations.  For example, one year we heated one with paraffin over winter and the other we heated with electric fan heaters. We then compared cost and efficiency and most importantly, how the plants fared. Some years we will grow identical crops grown in different composts or with different watering systems. We also use these houses to over winter our half-hardy rooted cuttings and tender perennials such as abutilons and fuchsias.