Horizon House formerly known as Cabot House

Cabot House in Bristol was demolished, recycled on site and then used in the construction of the new Horizon House. Whilst maintaining the environmental theme the new Horizon House is now one of one of Bristol greenest office developments. Horizon House is an important development for Bristol as it revitalises a key central location of the City. It has also sets the bar for the environmental quality of future developments.

Westmark who was the developer for the site, secured the Environmental Agency as a tenant which not only validates the “Green Credentials” of the building but also provided key employment opportunities for the region.

The development which is a mixed use scheme includes 70,000sq ft of offices space spread over five floors and is occupied by the Environment Agency, and 79 apartments some of which will be affordable housing.

The schemes eco-friendly features include natural ventilation, solar panels, and ground source heat pumps (extracting heat from the ground). This helps to keep running costs to a minimum.

Having carried out an extensive Value Engineering process on the Building Services element of the project with the rest of the design and construction team MJN Colston were responsible for the mechanical and electrical installation to both buildings. Specialist features of the service installation included Solar collection to provide preheat to the domestic Hot Water system and Photovoltaic collection to provide renewable energy to the buildings LV system.

The mechanical systems included a mixed mode form of ventilation through manual and automatic openable windows and Fan Coil Units with energy efficient EC motors.

The electrical installation included intelligent lighting control system which reduces the energy consumption of the lighting system.

This project picked up the BREEAM 2010 Award for Commercial Offices and was awarded a BREEAM rating of “excellent”.

Project Team

  • Client - Westmark Developments Ltd
  • Main Contractor - Sir Robert McAlpine
  • Architect - Alec French
  • Services Engineers - Hoare Lea & Partners
  • Quantity Surveyors - King Sturge
  • Services Value - £4.5m

The electrical installation includes and intelligent lighting control system to reduce the energy consumption of the lighting system.