Once complete the new flagship building will provide a highly energy efficient environment that will provide space for lectures, academic staff and support personnel, and there will also be common areas that will include catering facilities and zones for informal meetings.
The university’s requirements in relation to sustainability are to achieve a minimum BREEAM Excellent rating, with aspirations of achieving BREEAM Outstanding, which will reduce the building’s energy consumption and carbon dioxide emissions.
The client’s design statement assessed the application of low or zero carbon dioxide technologies (LZCs) to the proposed development. This was carried out by following Sheffeld City Council’s established policies set out in its Core Strategy (adopted March 2009).
The key policies discussed in this statement were:
Policy CS 64: Climate Change, Resources and Sustainable Design of Developments.
Policy CS 65: Renewable Energy and Carbon Dioxide Reduction.
GreenBuild Consult was appointed as sustainability consultants to carry out the role of principle BREEAM Assessor, and principle Energy Assessor; this was to ensure the dynamic simulations carried out were in accordance with all relevant planning policies, to ensure that the building will achieve the university’s aspiration of a BREEAM Outstanding rating.
GreenBuild Consult was able to guide the design team through appropriate measures to achieve relevant BREEAM credits, along with exploring options to satisfy thermal comfort targets within the building; extensive thermal comfort analysis throughout the design year was carried out to assess whether areas within the building would have overheating risks, particularly in the atrium; daylight analysis was also explored to demonstrate the need for artificial lighting in areas that was receiving insu cient natural daylight.
With the use of Integrated Environmental Services, (IES), Virtual Environment, (VE), software, many design iterations occurred throughout the RIBA Stages to ensure good design was achieved. Dynamic simulation modelling is an extremely accurate and powerful tool for assessing the environmental performance of a building. It can be used to model and analyse a range of sustainability factors from energy compliance and CO2 emissions, to overheating and daylighting analysis.
It is a much more commonly used for analysis of non-domestic schemes, which provides a much more accurate analysis than is possible with standard Part L energy assessment tools, such as SAP or SBEM. This is partly due to a much greater emphasis on external factors such as solar gain and the effect of glazing and thermal mass, but also due to more accurate occupancy, behavioural and energy use profiles.
Through intense consultations during the early design stages, significant cost savings were achieved through this process, such as reducing the floor-to-floor heights and demonstrating that all sustainability targets were still deliverable.
The consultation also included the required CO2 reductions needed to achieve planning policies. This amounted to a CO2 reduction of over 60% from initial design concepts. Through the use of a collaborative team approach, further analysis was conducted to identify the best design of the external façade.
Once thermal transmittances had been approved, the g-values for the external façade were then explored within the thermal modelto determine what the values need to be due to site orientation.
This was undertaken by specifying separate g-values for the north, south, east and west façades. As a result, the heating and cooling demand both reduced. The design stage BREEAM assessment is on target to achieve the university’s aspiration of BREEAM Outstanding, along with a reduction of nearly 70 tonnes of CO2 per annum.