What if my neighbour raises a Party Wall dispute ?
You may need to give your neighbour up to two months separate written notice under the Party Wall Act 1996 if your proposal is close enough to the shared boundary, and this in turn will require your neighbours explicit written consent in acknowledgement. This occurs independently of the Planning Process but as long as your proposal is valid under Planning law and the Party Wall Act, your neighbour cannot unreasonably withhold their consent. If a dispute seems likely, early advice from a Party Wall Surveyor may be crucial to ensure the required Notice is served correctly and reduce the risk of a later challenge.
Should your neighbour still seek to withhold consent, a boundary dispute may be said to arise and the Act contains rules to appoint specialist independent Party Wall Surveyor(s) to formulate an agreement or award. Your neighbour cannot use the Act to prevent legitimate development for which you have Planning Consent, but such disputes can delay progress and add cost before the agreement is inevitably reached.
Some properties have more complex boundary issues such as 'flying' or 'creeping' freeholds that may require additional advice from a solicitor to agree a Deed of covenant with your neighbour.
In situations where the Party Wall Act does not apply, following successful Planning Consent, arguably it may still be prudent to write a polite neighbourly letter to advise them of the Approval and that you intend to start construction work wholly within your own land, but seeking their acknowledgement and understanding out of courtesy.
In any event, you have no right to access or trespass beyond your own boundary line of ownership, so items such as scaffolding and gutters must be contained within your own land and not encroach onto adjoining land. No work can take place on or above the neighbours land without their explicit consent, but it is usually in both parties interests for a little mutual 'give and take' as ultimately your neighbour may need your consent to having their scaffolding on your land in the future.