Faithorn Farrell Timms LLP

Installation of External Wall Insulation at Staff Cottages

the project

Faithorn Farrell Timms was appointed by Thames Valley Housing Association (TVHA) in July 2017 to provide Contract Administration and Principal Designer services for the installation of External Wall Insulation (EWI) and associated works to 12 cottages in Godalming, Surrey.

TVHA's objective was to improve the thermal efficiency of the 12 cottages for their residents. The insulation product used was the Wetherby Epsiwall System with rockwool insulation.

our role

We undertook the role of Contract Administrator, providing traditional services under a JCT Minor Works Contract with Contractor's Design 2016. We also provided Principal Designer and Planning services.

Due to the nature of the works, we liaised with Building Control throughout to achieve Building Regulations compliance.

the challenges

  • Two of TVHA's residents dissented to the works at planning stage, submitting objections on the planning portal.
  • There was a disagreement between the contractors and Building Control in regard to the design of the soil vent pipes.
  • One of the residents had a 12-year-old Wisteria to the rear elevation of their property which they were reluctant to lose
  • We expressed concerns with the type of insulation proposed, which was EPS-based.
  • The site location was isolated and next door to a large new build scheme.
  • Planning delays meant that the works were undertaken between November to April over the winter months. The winter was a particularly cold one with cold spells and snow.

the solution

We contacted the Planners stating that we would omit the two dissenting properties so that the other ten residents that opted into the works could proceed. Planning consent was granted and works began. Once the dissenting residents saw the finished product, they asked if they could opt in at a late stage. We therefore negotiated a competitive cost with the contractors to reintroduce the two properties at the end of the programme.

We liaised with Building Control and the Principal Contractor in regard to the disagreement on the soil vent pipes. The durgos were removed and the soil vent pipes extended accordingly, the works were then signed off by Building Control.

Special design consideration was given for the Wisteria and it was decided that appropriate fixing points would be introduced into the system to allow the Wisteria to be re-attached, whilst keeping it off the face of the building to prevent damage to the EWI system.

We collated data from the manufacturer on the two types of insulation permitted for use as part of the Wetherby Epsiwall system. This was either the EPS-based system with lamella fire breaks or a rockwall insulation. We recommended to the client that rockwall insulation be used as this is fire resistant, reducing the fire risk if the render was damaged leaving the insulation exposed. Whilst there was a slight cost increase associated with this, competitive costs were negotiated with the contractor.

Due to the close proximity of a live building site, consideration was given to potential impact on our works in regard to access for deliveries and close monitoring was undertaken. It was noted that the new build contractors were using our client's private car park which had recently been resurfaced. We liaised with the new build contractors to deter them from using the car park. The car park had already had two spaces taken up by a welfare unit and we did not want the remaining resident’s car parking spaces to be used by the contractors working on the neighbouring site.

We managed the client, contractor and resident expectations in regard to delays associated with the weather and continually liaised with the contractor to ensure that works were completed on time. An extension of six weeks was required beyond the intended completion date; however, this was the result of the two previously omitted properties being added back in.

added value

Whilst scaffolding was erected for the purpose of installing the EWI, we undertook inspections of the roof coverings, preparing a performance specification for our client. Also, to the single storey side returns, the roof coverings were overhauled with any missing or slipped tiles replaced and reinstated.