• Slide

    London Borough of Islington

    Value: £261,649
    Location: Neptune House, King Henry Street, London, N16 8LS
    Form of Contract: Term Partnering ACA TPC 2005
    Duration: January 2013 – April 2013


Project Brief

Neptune House is a brick built block of 36 no. residential flats built in the 1960s. The project brief involved the over cladding with an External Wall Insulation system to the exterior of the building to include all associated works to mechanical and electrical services, and the installation of new Juliette balconies. The Neptune House project is a ‘bolt on’ scheme and part of the Capital and Cyclical Improvement Programme we are carrying out for LB Islington.

Aims & Objectives

To improve visual appearance and environmental performance of the property.

Scope of Works

A complete overclad of the existing building envelope in an Alsecco External Wall Insulation (EWI) system which included the following works:-

  • Scaffold the entire building to accommodate all multi trade works
  • Installation of new double glazed windows
  • Installation of new Juliette Balconies
  • Installation of powder coated aluminium window sills 
  • Extend projected tiled roof gable to incorporate the new External Wall Insulation 
  • Re-positing of soil pipes and branches and rain water pipes 
  • Re-site communal Ariel CAB x 2
  • Extension of boiler flues, condensing pipes and toilet overflow pipes

Key Challenges

The key challenge was to retrofit an insulation system to an occupied building ensuring that all fixtures, fittings and sections of the building were considered and able to be altered accordingly.

To adhere to the Programme of Works set by the Client, we had to complete the works during the winter months when the products being used were completely temperature dependant.

We carried out internal surveys to all boiler installations to determine suitability for extending pipe work through the new External Wall Insulation (EWI). As a result of these surveys, 8 no. boilers had to be changed.

During the works, we had to maintain all communications; satellite systems, telephone lines and all household amenities by fitting these to temporary positions, maintaining and refixing to the building on completion of the works, ensuring that the
relevant anchor points were included as part of the original design. We also had to carry out mechanical alterations to toilets and waste pipes within occupied properties.

We installed EWI with the minimal external fixtures and fittings of services. The majority of these are now concealed beneath the insulation panels.

We installed new windows to suit EWI design including new especially manufactured extra wide aluminium window sills.

Delivery Targets

The works were commenced in January 2013 with the target of completion by 29th March 2013 to ensure availability of ECO funding secured previously by London Borough of Islington through British Gas. Whilst every effort was made to achieve this target, the extended winter period with extremely cold temperatures through February and March caused a 4 week delay to completion, hence a completion date of 30th April 2013 was achieved. Following property specific surveys, it became apparent that the replacement of a number of boilers would be necessary. This work was carried out during the period of inclement weather which ensured that external works could continue whenever possible.


The challenge of retrofit of this nature on occupied property's, was to ensure that there was minimum impact to the Residents during the works. This was achieved through very close liaison by our site management and operational staff.

Key Outputs

This block of residential properties has undergone a complete cosmetic change to the outside of the building giving a marked improvement for the Residents’ comfort and drastically reduced energy bills.