Date Completed: 07/12/2016


We were instructed by our client AP Architecture, to undertake a resistograph assessment for a private house extension on a site in Tamworth. Decay detection was confirmed on trees protected by a tree preservation order (TPO).  A detailed mitigation plan and replacement planting scheme was prepared to discharge the conditions associated with the TPO consent.


  • From the outset, establish the client’s full ambition for the site and specifically the trees
  • Undertake a detailed visual tree assessment aided with a nylon mallet
  • Undertake an invasive decay detection assessment if considered necessary, following the initial assessment to identify the extent of decay
  • Liaise with the Local Planning Authority Tree Officer to agree in principle the proposed arboricultural solution
  • Submit a TPO application to the Council with full and detailed justification for any tree works.


Following an initial meeting with the site owner and local residents, it became apparent that the poplar trees located on the boundary had become a nuisance in terms of dropping significant branches. Further to this for the local residents whose houses are located only 8-10m from the trees, there was significant apprehension in relation to what may happen if the trees were to fail.

Due to the trees being between 15-25m in height, this was understandable. The initial contact with the residents was a key part to the success of this projects.


A visual tree assessment was undertaken to assess the physiological and structural condition of the trees. Via way of using a nylon mallet we were also able to establish that there was significant internal decay associated with each of the trees.

To confirm the extent of decay, a decay detection assessment was undertaken using a Resistograph PD400 which probes the trees to 400mm. The resistograph has two sensors on the drill bit measuring the power required to maintain the drill turning ata constant speed, and the pressure being applied to the top of the drill. The resistograph assessments were undertaken predominantly at 0.5m – 1m above ground level. The decay detection confirmed the initial visual tree assessment and was used to support the application to remove all trees which were protected by a TPO.


Wharton Tree & Ecology Consultants has now been commissioned to prepare a detailed mitigation and replacement planting scheme to discharge the conditions associated with the TPO consent.  In addition we have also undertaken a BS5837:2012 survey and constraints assessments and prepared a detailed arboricultural impact assessment to support a planning application submitted to significantly extend the listed building on site.

It was agreed with the Tree Officer prior to the TPO application that he was happy with the approach to deal with the tree felling separately to the planning application, as this would be required even in the event of planning permission for development not being granted.

Full planning consent has been granted.