Most small single-story extensions do not require full planning permission and can be built within permitted development rights. This applies, however, only if all relevant planning and design criteria are met, and there are no restrictions that limit or revoke your right to permitted development.
In general, large extensions and double-story additions will require full planning permission, which can be obtained through a householder’s planning application. In order to extend flats and maisonettes, planning permission is always required because they do not have permitted development rights.
Although some extensions are permitted developments, they also need prior approval. An application for prior approval must be approved by the local planning authority first before any work can proceed.
It is advisable to obtain a lawful development certificate for extensions that will likely fall within permitted development since it is the only way to ensure that your extension is legal. This will likely be required if you ever wish to sell the property in the future in order to avoid retrospective planning issues, enforcements, or penalties.
After planning permission is granted, it is likely that building regulations approval will also be needed, depending on the extent of the work.
You may still need planning permission even if your project complies with all permitted development criteria if there are hidden constraints that limit or remove your permitted development rights.
Every development carries the risk of hidden planning constraints that can turn the simplest of projects into very complex applications.
Every type of development must meet certain design criteria in addition to meeting all of the necessary planning policies, which vary between local planning authorities. If, for example, a 3-meter extension fails to meet any of the design or planning criteria, then full planning permission would be required.
Additionally, there are many hidden constraints such as article 4 directions, section 106, conservation areas, and even just living under a flight path can remove your permitted development rights, so everything will need full planning approval. Two houses in the same town could do the exact same development, but one could be built under permitted development while the other requires full planning permission.
Furthermore, specialist reports may also be required with all the usual supporting evidence and drawings. Heritage statements, flood risk assessments, transport surveys, and wildlife reports are just a few examples.
In addition to securing planning approval, you will need listed building consent and building regulations approval before any work can begin. The illegal modification of a listed building without obtaining the necessary approvals is a criminal offense.
Read also: https://mimimika.com/home-improvement/