The planning system is based on the principle that all 'development' requires planning permission. However, the Town and Country Planning (General Permitted Development) Order 1995 gives deemed planning permission for specified types of development (provided prescribed conditions are followed) to minimise the numbers of planning applications Councils would otherwise face. One type is extensions to property.
From 30 May 2013, for a three year window, it will be possible for homeowners to erect even larger single storey rear extensions to their properties than currently deemed permitted. At present such extensions must not extend beyond the original rear wall of the property by no more than 4 metres for a detached property and 3 metres for any other. The new right provides that where the extension is less than 4 metres in height, it is not within a National Park (or the Broads), an Area of Outstanding Natural Beauty, a Conservation Area or Site of Special Scientific Interest then the restriction is doubled to 8 metres for a detached dwelling and 6 metres for any other.
However, to make use of the new larger sizes, you will need to go through a prior (free) approval process by inform the Council using their prescribed form who will then give your neighbours 3 weeks to object. If they do not object (or if the Council fail to respond before 42 days have expired) you can proceed. If a neighbour objects the Council will need to decide whether your proposal will harm the amenity (general planning issues are not relevant) of any adjoining properties and grant or refuse approval accordingly.
But the worry is that some householders may overlook the notification process, or they may overlook the need for the parallel permission which must always be considered, that of Building Control. May 30th brings no change to Building Control. Regrettably it is suspected that there are many current extensions, and now the up and coming enlarged extensions, where people have overlooked the fact that building within 3 metres of a public (as opposed to private which remains owned by the house owner) sewer requires consent of the water company as part of the building control process.
Indeed, from 1 October 2011, the responsibility for private shared sewers and private drains transferred to water and sewerage companies. This means a lot more public sewers now exist and yet many house owners may fail to realise this. This change in legislation may affect your future building regulation application. This is because for building regulations applications involving extensions, some Councils will check the sewer maps as the application is processed and if they find a sewer nearby they will inform you at the earliest possible opportunity. It is a legal requirement that you obtain written consent from the relevant water company to build over it or within 3 metres of it.
As mentioned, what about where people had already erected an extension over a shared private sewer within their own boundary before 1 October 2011, and this private sewer is now public? Is backdated consent needed? There is no legislation on the point but academics consider that the water company will exempt a house from doing so, and where an extension was already built over or within 3 metres before October 2011, any damage caused by the water company needing access through the extension that blocks the drain will be at the company’s own expense provided the home owner obtained any required building control consent for the extension itself. A major worry for homeowners now.
If no building control was obtained, then the practical solution would be to speak to your conveyancing solicitor and discuss legal indemnity insurance for 'lack of a build-over sewer agreement'.