I am sure that most of you are aware that a permission for a house extension may be obtained either through a Householder Planning Application or a Permitted Development Application. What you might not know is that there is still a number of restrictions and constraints that may reduce the likelihood of such applications being approved. The most common of them are listed below:
Planning Considerations and Restrictions:
Trees on application site.
If you are applying for a house extension and it requires a householder planning permission, whether it is because the height or depth exceed those allowed under Permitted Development rules or for any other reason, you have to account for trees on a development site that might affect the proposal. Normally all trees are protected in Conservation areas, alternatively particular trees can be protected by council if they have a significant impact on their local surroundings.
In such case a tree report prepared by arboriculturist would be required by the council.
Such report will need to provide information on size of the tree root protection area and what is its relation to the proposal.
It is worth noting that tree Root protection area can be slightly altered (trimmed) and/or shown as either circle or a rectangle that can be rotated to avoid the impact by the proposal.
Overall, one has to remember to allow additional budget for a tree consultant.
Right to Light Easement
Under The Right to Light Act 1959, if a property owner has benefited from the sunlight from a window for 20 years, he would have the right to prevent the outlook and sunlight being blocked by any future development on the adjoining site. Such a provision makes a potential development on adjoining site extremely difficult.
The owner of the property with Right To light easement may object to a planning application requesting the application to demonstrate it will not affect his right to light.
If he does not object and the planning permission affecting his Right to Light has been approved, it could become a legal issue which if not dealt with satisfactorily for the claimant may end with either reduced size of extension or no extension at all. It is tremendously important to let your architect know at the beginning that a particular window on neighbouring site may benefit from such easement.
Outlook
Your extension cannot affect the outlook from a habitable room of an adjoining building at the first floor level. Basically, it cannot be in the way of a 45 degree line taken from the nearest neighbouring window .
If it does, your architect needs to amend the proposal so that it has no impact on the adjoining property, otherwise the proposal for sure will not be supported by the council. It is a common mistake to overlook this constraint and very often it ends with the application being refused, if no provision has been made to avoid it.
Although the 45 degree line in many councils is just notional the impact of the proposal is meticulously assessed by the council.
Overlooking and Privacy
It is a common issue with raised level patios and balconies.
This is one of the reasons why it is normally not allowed to use a flat roof of a single storey rear extension to be used as a balcony or terrace. It is preferred by most councils that a Juliette Balcony is proposed instead.
Very often we were asked by the local authority to reduce the height or extent of patio or remove a rear balcony so that it does not create an overlooking problem.
Sometimes a good solution is to provide privacy screening in a form of dense plants or screens.
Restrictive Covenants e.g., Right of Way
You may remember when you bought your property, you were provided with Title Deeds.
This document shows what land is in your ownership but occasionally it also shows which part of your land allows for an easement to your neighbour. This happens if there is a drive between two buildings and half of the alleyway belongs to each neighbour.
If there are garages or rear garden gates, then each neighbour would have a right to use the full width of the shared alleyway to access part of his own property conveniently.
Unfortunately, if the alleyway is shared between the two neighbours, nothing can be built even entirely on your side of the alleyway as this would make the use of the entire alleyway for the neighbour impossible. Unless you and the neighbour are freeholders and you are both happy to change the existing arrangement which can later be confirmed with a solicitor.
Party Wall Matters
Party Wall etc. Act 1996 is a legislation ensuring the rights of two neighbours are secured when works are proposed in proximity of shared party walls.
There are many development activities that would affect party wall at the construction stage, but the subject is so vast that we will cover it in another article.
In terms of planning, most extensions are proposed on the boundary in the way that no part of the extension would encroach the boundary line.
In some cases the neighbours agree that the new extension wall can be built astride the boundary, so half of the wall would be sited on the neighbouring land and the other half on the application site. This means that the ownership section in the application form has to be changed and has to indicate that the application site does not belong entirely to the applicant.
Conclusions
All the above planning constraints are not exhaustive, and I tried to list the most common of them. Should your case be different, and you need a professional advise Atelier 41 Architects are always happy to help with any questions you might have.