Buildings are responsible for half of UK's energy use and carbon emissions, the reduction of which is key to mitigate the impacts of climate change. Most of the energy used in UK buildings is for heating and lighting, the need for which is determined, to a large extent, by building form and envelope, and the thermal properties of construction. Glazed surfaces in building envelopes enable daylighting but affect overall energy consumption due to heat loss during winter and unwanted solar heat gain during summer. Careful design of the envelope considering both thermal properties of construction and glazing characteristics is thus the first step in reducing energy demand from buildings. This research investigated the sensitivity of building envelope construction comprising multi-layered wall construction (36 types) and varying sizes of glazing (10-90%) on energy demand in a typical commercial building through dynamic thermal simulation. Brick and lightweight aggregate concrete block wall with 100 mm blown wool fiber insulation in-between layers and a plastered internal finish produced the optimum result with glazing levels of 30%, 20% and 10% on the south, north and corridor zones respectively. Optimum window sizes change with construction type and building orientation indicating the need for the integrated performance-based design of building envelopes, as opposed to the conventional rule of thumb approach. The role of optimization and computer assisted design exploration is discussed, as well as the feasibility of optimum solutions from environmental, social and economic perspectives.
In REF a Sensitivity Analysis was performed on a building envelope in order to quantify the effect of the construction type and window size on the thermal performance of an office building.
Low carbon buildings: Sensitivity of thermal properties of opaque envelope construction and glazing
Energy Procedia
Engineering