Services
Acoustics & vibration
The discipline where the standard is unambiguous and the argument is always about the baseline. We measure it properly, for long enough, and we say what the weather was doing.
What this involves
- Five days minimum, weather logged
- Baseline survey
- BS 4142, 8233, 5228, 6472, 7385
- Standards
- Class 1, calibrated annually
- Instruments
- Four, two corporate
- IOA members
A BS 4142 assessment is a comparison between a rating level and a background sound level, and almost every dispute we are asked to review is a dispute about the background measurement rather than the calculation. A background survey taken over one dry Tuesday night in August is not a background survey. We measure for a minimum of five consecutive days including a weekend, we log the weather, and we exclude periods where wind speed at 10 metres exceeded 5 m/s, which is what the standard asks for and what is routinely skipped.
For residential schemes near roads or rail we assess internal levels to BS 8233 and, where windows have to be closed to achieve them, we say so on the drawing and we specify the ventilation that follows. A scheme that only meets 30 dB LAeq with the windows shut and no acoustic ventilation is a scheme that will overheat, and that is now an Approved Document O problem as well as an acoustics one.
Vibration work is mostly rail and construction. We measure to BS 6472 for human response and BS 7385 for structural risk, and on the historic buildings we work near we will usually recommend a trigger-level monitor with an alarm rather than a one-off prediction, because a prediction does not stop a piling rig.
Sectors
Where we do this work
Housing & mixed use
From nine units to 1,400. Most of our work, most of our planning conditions discharged, and where biodiversity net gain bites hardest.
Industry & manufacturing
Environmental permits, BS 4142 boundary assessments, odour, and the compliance letters that follow an unannounced regulator visit.
Transport & rail
Vegetation clearance ecology, noise and vibration near track, and lineside contaminated land where the ballast has been there since 1898.
Also from Thornfield
Other services
Ecology & biodiversity
Preliminary appraisals, protected species surveys and statutory biodiversity net gain, with the metric run before the layout is fixed rather than after.
Read moreAir quality & odour
Construction dust assessments, road traffic and combustion dispersion modelling, and odour assessment for waste and wastewater.
Read moreLand & groundwater
Phase 1 desk studies, intrusive investigation, remediation strategies and verification, plus hydrogeological risk assessment for the Environment Agency.
Read moreGet in touch
Tell us about the site before you buy it
A twenty-minute call at option stage is the cheapest environmental advice you will ever take, and occasionally it is the advice not to proceed.