Office buildings
The PowerGen headquarters is a good example of a high thermal mass owner- occupied office, typical of those built in the UK since the early 1990s. These buildings are characterised by long narrow floor plates, with a central atrium to optimise the use of daylight and natural ventilation. Thermal mass is exploited through the use of exposed concrete floor slabs in conjunction with underfloor and natural ventilation. The PowerGen building has proved to be successful, with good occupant comfort and overall satisfaction.
Courtesy of the British Cement Association
Fingal County Hall was completed in May 2000 and is a showpiece of modern architecture in the otherwise undistinguished village of Swords Co. Dublin. Responding to the 'green' brief, the architects used a range of passive energy saving devices, including thermal mass which is provided by a coffered concrete ceiling. The office areas are naturally ventilated, and it is estimated that the passive approach to cooling provides around 25 W/m2. Careful attention has been paid to the lighting design, which maximises daylight penetration through the clever use of light shelves and white soffits that slope upwards towards the windows.
Courtesy of The Irish Concrete Federation
Toyota's UK headquarters in Epsom, Surrey, were completed in 2001 and provides 14,200m2 of high-quality office space that met the client's brief for flexibility and low energy. Cooling is achieved with a combination of mechanical ventilation and exposed coffered soffits. An interesting feature of this building is the use of hybrid concrete construction (insitu and precast elements). This comprises hidden in-situ reinforced concrete in conjunction with exposed precast coffered floor units and structural columns that are mostly precast (with an internal steel column).
Courtesy of The Concrete Centre and the British Cement Association
Vodafone's UK headquarter buildings in Newbury uses a combination of thermal mass, chilled beams and mixed-mode ventilation to meet the relatively high internal heat gains. The finished buildings comprise 51,600m2 (43,000m2 of office space) and are intended to accommodate around 3,000 employees. There are seven independent buildings, each with two rectangular sections joined along their full length by central atriums. The decision to opt for a low-energy solution was influenced by the client's own desire to build an environmentally friendly building, and by local planning considerations. The potential to use thermal mass for cooling was identified by the architect before the structural or building-services engineers were appointed. The geometry of the building and its layout were determined by the architect based on the site topology and access provisions, but also with some awareness of the features necessary to maximise the cooling potential from the thermal mass.
Courtesy of The Concrete Centre and the British Cement Association
The National Trust headquarters in Swindon opened in July 2005, and is proving successful in achieving a design brief which centred on the need for excellent environmental performance and a high level of sustainability. Extensive use has been made of natural ventilation, thermal mass and renewable energy in the form an 80kW photovoltaic array, making the development almost carbon neutral. Whilst this is clearly a prestigious HQ building, surprisingly it was built by a commercial developer within the budget for a typical speculative office of a similar size.
Courtesy of The Concrete Centre and the British Cement Association
Completed in 2000, Canon's UK headquarters are situated on a 25-acre site of mature, sheltered landscape at Woodhatch near Reigate. The 11,500m2 of office space has been designed in sympathy with its surroundings, taking advantage of natural ventilation which is ideally suited to the quiet, unpolluted environment. The ventilation strategy works in unison with coffered concrete soffits to provide passive cooling. A combination of cross and stack ventilation works with the thermal mass to maximise the cooling potential. The buildings have been orientated to optimise solar gains and a deep roof overhang in conjunction with cloisters keep direct sunlight out while minimising the need for artificial light.
Courtesy of The Concrete Centre and the British Cement Association
This case study describes how a multi-story concrete office-building can be re-designed for low energy demand and high degree of thermal comfort.
- Full case in Norwegian: Report 1 - Report 2
- Executive Summary in English
The desire to create a reference building, not only a true technology showcase for the sector but also the cornerstone of our teaching approach, was a driving force behind the project. Part of the Strategic Development Plan for 2002, the idea of building a reference infrastructure component, aiming in every respect at High Environmental Performance, thus became the embodiment of a breakaway strategy.
Project report on the office building ‘SD Worx’. Good thermal summer comfort is achieved by passive cooling of exposed concrete ceilings. Night ventilation air entering the north façade cools the concrete slabs and leaves through a vertical ventilation zone located at the south side. In addition, two concrete tubes serve as an earth-to-air heat exchanger, which cools down the ventilation air on hot summer days.
Good description of a passive cooling concept by use of exposed concrete parts and night ventilation. Measurements of indoor and outdoor temperature during summer 2002 are reported and compared to the results of thermal simulations. The positive effect of concrete on the peak temperature and the phase difference between indoor and outdoor temperature is described.
Concrete core activation by using "wing" floors to reduce energy consumption.
First building in the Netherlands using thermally activated concrete hollow-core slab floors.