Question: My neighbour is having an extension built within 12ft of my property and there is now talk of driven piles as the soil type is soft clay. I have been served notice, but am concerned this change in plan may cause damage to my property.
Answer: This was not under the terms with which you reached agreement and non-agreement or dispute seems to have occurred. If they are driven piles being proposed, I would urge you to refuse to accept driven piles in that proximity to your property. You could appoint your own Party Wall Surveyor or ask the Agreed Surveyor to carry out a schedule of condition. Your neighbours Architect should re-think their proposed variation in the foundation design and perhaps consult a Structural Engineer. You may also enquire as to the extent of the Contractor’s insurance policy in particular their third-party coverage. Similarly, the level of professional indemnity insurance held by the Architect or Structural Engineer.
There are; however, driven foundation systems that minimise vibration and are suitable for placing piles near existing property. Diesel hammers are to be avoided where possible.
Sheet piles are used in many forms of construction and dependent on the location and application may require more archaic insertion techniques i.e. diesel hammers. Generally in the construction industry we regard the CFA pile (continuous flight auger) as the elitist technique.