An extension in Stratford starts with two checks, and both of them can change the whole project rather than a detail of it.
The first is listing. With over 3,300 listed buildings and structures in the district, this is a real question rather than a formality, and it extends beyond the house itself: a boundary wall, an outbuilding or a structure in the garden can be listed as part of the curtilage. Where a building is listed, an extension needs listed building consent as well as planning permission, consent covers the interior too, and the design has to start from that constraint rather than have approval bolted onto it later.
The second is water. Policy CS.4 in the council’s Core Strategy deals with the water environment and flood risk, and on some sites a flood risk assessment forms part of the application. Where that applies it can affect floor levels, construction and even whether a particular footprint is acceptable. Checking the Environment Agency map at the outset costs nothing and occasionally saves a design fee.
On unlisted, undesignated property this is conventional work. A single storey rear extension of up to four metres on a detached house or three on a semi can fall within permitted development, and the larger home extension route allows up to eight metres or six by prior approval with neighbours notified.
Our extensions work is set out in more detail there, including the stages of a build and how the Building Control inspections fit around them.