The construction of a conservatory is a very popular way of adding extra, flexible space to a home, in the form of a beautiful, relaxing, light and airy space, which can be used as an extra living or dining area for example. Generally it is not necessary to obtain planning permission before beginning work on building a conservatory, as it is a ‘permitted development’, but there are certain situations where it may be required.
Planning rules refer to the ‘original house’, as it was first built, or as it was in 1948. Recent legislation means that larger single storey rear extensions or conservatories are permitted developments until 30 May 2016. This means the size limit for an extension or conservatory has increased from four to eight metres from the original house for detached houses and from three to six metres from the original house for attached houses. For this larger size of conservatory it would be necessary to notify the local planning authority. They may ask for additional information and can notify the neighbours of the intended construction, who could then have the right to lodge an objection.
There are other situations where planning permission might be needed for a conservatory. It is worth considering the size of the proposed conservatory, as if it were to cover more than half the land around the original house, or to project beyond the front elevation of the house, or beyond the side elevation where this is adjacent to a road, then planning permission would be required. A conservatory to the side of the house should not be wider than half the total width of the house.
There are also limits on the height of a conservatory: a conservatory to the rear of the house shouldn’t exceed the maximum single storey height of 4 metres and its eaves and roof ridge must not be taller than the highest point of the house. If the conservatory were to be double height, or were to exceed the rear elevation by more than three metres, or be within seven metres of a boundary to the rear of the house, then planning permission would be needed.
If you live in an area of ‘Designated Land’, such as an area of Outstanding Natural Beauty, or a national park, a World Heritage site, or a conservation area, then a conservatory should not project from the rear wall of the original house by more than three metres for an attached house and by more than four metres for a detached house. In these areas a conservatory is only permitted to be single storey in height and cannot be located on the side of the house. Some general points to consider are that the conservatory roof style should not be radically different from that of the house and the conservatory design should not have a balcony, veranda or raised platform, or else planning permission would be needed.