New builds and warranties
A new-build plot sits beside an electricity substation the surveyor noted. What electromagnetic test was not part of the home survey?
No electromagnetic test was part of the home survey. The surveyor noted that the new-build plot sits beside an electricity substation, which is a location note. It is not a measurement of fields, not a health study, and not a reading taken at the plot boundary. The inspection has recorded the neighbour on the plan. It has not tested anything electromagnetic, has not modelled exposure, and has not decided that the substation is acceptable or unacceptable. NHBC describes Buildmark as a 10-year warranty and insurance product. Noting a substation does not open a claim under it.
Last reviewed 24 October 2026. Written for buyers in England and Wales unless this answer says otherwise. No named surveyor has signed this page. It is general guidance, not a report on your house, and not legal advice.
What is the fuller explanation?
Substations worry buyers because they are obvious on a new estate and because the science is easy to blur into the snagging list. A home survey can say the compound is next door and can note noise, access or a damaged boundary if those were seen. It does not carry the instruments for an electromagnetic survey, and this visit did not pretend to. Snagging is about the house as built.
Ask the solicitor what the searches and the estate plan say about the substation, and keep that separate from the home survey. If you want measurements, that is a specialist test this inspection did not include. NHBC's Buildmark is a warranty and insurance product the survey does not open. Do not tell a lender an electromagnetic survey was done because the substation was written down. The note is the note. The test was not part of the job.
What should you ask your surveyor?
- What did you actually note about the substation, other than its position?
- Did the inspection include any electromagnetic measurement?
- Are you linking the substation to a defect on the plot, or only recording it?
What are the typical next steps?
- Treat the substation note as location, not an electromagnetic test.
- Ask the solicitor what the searches say about the compound.
- Do not describe Buildmark as opened by this note.
Costs vary with the building and with who you instruct. Where this page does not cite a published figure, ask the surveyor, a relevant specialist, or your solicitor for a written quote. Do not treat a forum average as the price.
Also asked about this
If the surveyor could hear a hum, was the field measured?
No. A hum, if one was heard, is a noise. It is not an electromagnetic measurement. The home survey did not include that test. Hearing plant is not a reading at the boundary. Position and noise are not a measurement of anything electromagnetic.
Does a new-build warranty cover the substation because the plot is new?
No. NHBC describes Buildmark as a 10-year warranty and insurance product for the home. The survey does not open a claim, and it did not test the substation. A new plot beside electrical plant is not the same as a warranty finding.