Conservatories often increase a home's square footage and value. It's faster and cheaper than building an expansion. You do not need permission from a neighbour as a Conservatory is a "permitted development rights," meaning they can be built without permission.
Although not needing planning permission for a simple conservatory, approval is needed if a conservatory would compromise any of these things.
However you should also know that being allowed to build a conservatory does not mean you may instantly start. Notify the council before proceeding. Since your neighbours have the legal right to comment on your extension, it is best to be open and clear with them. This ensures that your conservatory will not negatively effect the neighbourhood.
It cannot exceed 4 metres in height, or 3 metres if it is within 2 metres of a border (if within 2m of a boundary).
The conservatory may house half the garden.
Roof ridges cannot exceed eaves.
The house's side width cannot exceed half.
If the construction of your conservatory will include building against your neighbours fence or excavating within three metres of the adjacent property, you are required to give your neighbours notice at least two months in advance. Simply having a conversation with them is not enough.
If your property is in a specific category, these criteria are amended further. Article 2(3) restricts Special Scientific Interest land. This category includes properties in conservation areas, national parks, World Heritage Sites, or remarkable natural beauty.
Making higher-level additions is likewise prohibited. Side expansions and building cladding are prohibited.
If your property is new, you may be eligible to claim a VAT exemption on the conservatory's purchase if construction hasn't finished. You must also follow building construction laws