PWS Essex knowledge guide
Excavation Near Neighbouring Buildings
A practical guide for homeowners, developers and adjoining owners in Essex, explaining when the Act may apply and how to prepare.
Quick answer
Excavation can be notifiable when it is within three or six metres of a neighbouring structure and meets the depth or 45-degree tests in Section 6.
Understanding the three-metre test
Measure horizontally from the proposed excavation to the adjoining owner’s building or structure. The Act may apply where excavation is within three metres and will go below the bottom of the neighbour’s foundations.
When the six-metre test matters
The six-metre provision uses a line drawn at 45 degrees from the bottom of the neighbour’s foundations. It can capture deeper excavations, piled solutions and some basement or retaining-wall works.
Information needed for a valid Notice
The Notice should be supported by plans and sections showing the site, excavation position and depth. For six-metre cases, drawings and construction details are particularly important.
Local considerations in Essex
Across Essex, suburban extensions, loft conversions and infill development frequently place new foundations and structural work close to neighbouring homes. Clear drawings and early service are particularly valuable where plots are compact or ground conditions influence foundation design.
We advise throughout Chelmsford, Basildon, Brentwood, Grays, Thurrock, Epping and surrounding Essex communities. The correct answer depends on the drawings, structural details, neighbouring foundations and ownership—not simply the project description.
How the Party Wall process usually progresses
Start with a review of the architectural and structural information. Where the Act applies, the correct Notice or Notices are prepared and served on the legal adjoining owners. A neighbour may consent, appoint their own surveyor or agree to an Agreed Surveyor. If a dispute arises, the appointed surveyor or surveyors prepare an Award recording the works and reasonable safeguards.
Notices should be dealt with before notifiable work begins. Early advice allows statutory periods, neighbour communication and any Schedule of Condition to be built into the construction programme.
Frequently asked questions
Does every excavation within three metres need Notice?
No. The depth comparison with the adjoining foundations also matters.
How are foundation depths confirmed?
Existing information, inspection, trial holes or professional assumptions may be needed depending on the project.
Can work start after consent?
The relevant notice period and any agreed conditions must still be respected.
Related Party Wall guides
Need advice in Essex?
Send PWS Essex your plans or describe the work and we will explain the likely Party Wall requirements.