A design and build project to deliver Imperial Tobacco’s new, BREEAM Excellent, global headquarters in Bristol city centre. The client’s aspiration was to create a sustainable, state of the art global headquarters. The new four storey office building accommodates 500 staff and includes an auditorium, gym and restaurant all incorporated around a feature ‘floating’ staircase.
The structural frame of the building includes reinforced concrete flat slabs, limited downstand beams and suspended ceilings. The design of the building meant there was no requirement for a high end concrete finish and so a reusable formwork system could be used. Unlike traditional, single-use plywood formwork, the Peri Sky deck system uses aluminium formwork panels which can be reused multiple times. The reusable formwork reduced timber waste by approximately 50% in comparison with traditionally built concrete framed buildings.
A water system which incorporates use of rainwater harvesting and greywater helps the building to use water efficiently by reducing potable water consumption.
The energy and heating needs of the building are serviced by a remote energy centre. Here, the building’s internal temperature and ventilation are controlled through the use of a biomass boiler, highly efficient traditional gas fired boilers, four pipe fan coil units and a turbo core chiller.
550m2 of solar PV panels at roof level supply a renewable source of electricity, while PIR absence detection lighting controls, daylight balancing and out of hours power down help to manage the building’s energy use.
Previous enabling works on the site had resulted in large amounts of stockpiled concrete. Through early involvement with subcontractors, we were able to reuse this material. Concrete was crushed onsite for use as aggregate and a ‘borrow pit’ was also created, allowing us to stockpile good quality material for use throughout the project. This reuse of material reduced the amount of waste being taken offsite, reduced the amount of virgin material needed and avoided almost 500 lorry movements. This helped to reduce the impact of the project locally and saved around 5.5 tonnes CO2.
Prefabrication of certain building components reduced waste. Two hundred and eleven combined electrical/mechanical modules, as well as Electrical and Mechanical risers, were prefabricated offsite. These pre-tested elements were simply lifted into position in ceiling voids, and then connected up. This method significantly reduced material wastage onsite, with almost no waste produced for this part of the installation.
A pallet repatriation scheme and a local Wood Recycling Project was utilised to ensure usable timber was kept out of the waste stream, while the use of gravel margins for landscaping avoided the need to cut paving slabs.
Members of the site team became Reading Buddies, supporting a local primary school’s scheme. Each volunteer visited the school on a weekly basis to read with their reading buddy, and after 6 months the children had made excellent progress with their reading ability. The Project Manager won an award for his team’s involvement and support of this scheme from the local charity Ablaze, which develops sustainable partnerships between businesses and schools. To build on this, the team organised a book collection from various BAM sites and the regional office and donated these books to the school.
BAM contacted a local college which offered modern apprenticeships in construction and arranged for students to make trade targeted visits to the site. These visits allowed students to track the progress of a real site and deliver assignments based on actual site activities. For many of them it was the first time they had been on a construction site. In total 82 apprentices and eight lecturers visited the site.
The site team participated in a local schools ‘spaghetti towers’ activity day. After a talk from the project manager, tour of the site and a discussion about the different roles in construction, the students were set a classroom activity. Taking on different construction roles, they were challenged to build the tallest tower out of spaghetti and marshmallows.
The health and safety of operatives is paramount, on this project the use of prefabricated components helped to reduce the health and safety risks of working at height. Each pre-fabricated electrical and mechanical service module only required eight fixings from suspended points, which helped to dramatically reduce the time required to work at height.
A green roof was incorporated into the separate energy centre. Bird and bat boxes were installed throughout the site while hedgerows on the western boundary were protected, increasing biodiversity on site.
The carpark lighting was designed with consideration of the bats habitats, with low lux levels to close proximity to the hedgerows.
