The challenge of shape and form: understanding the benefits of efficient design (NF72)
The energy and carbon requirements of Building Regulations do not explicitly give credit for housing designs with lower heat loss areas or more efficient shapes. Yet through a better understanding of these issues, designers and developers can significantly reduce the energy consumption of new homes, potentially at little or no extra cost. This report explains the issues, and discusses ways that designs can be improved.
The pursuit of lower energy consumption through more efficient shape and form need not have to lead to bland or monotonous housing designs. The report discusses how the most inefficient design features can often be avoided or replaced by alternatives which are still architecturally interesting. Many designs can provide better comfort conditions for the residents as well.
Summary of content
Form factor and why it matters
An introduction to ‘Form Factor’ and how it varies across typical home types such as apartments, bungalows and houses (terraced, semi-detached and detached). Compares the space heating demands of different types of homes.
Building Regulations compliance
Explains how the current energy/carbon methodology in Part L1A of the Building Regulations (where DER must match the TER of a notional dwelling), does properly reflect the fabric and efficient services of a design but does not give credit for improved form factor.
In this section the report considers variations in architectural features/shape, such as bays, dormers, rooflights, recesses, staggers and integral garages, and the effect these can have on energy efficiency of the home. Compares the benefits of improved shape and form with those achieved with the orientation of the home.
The report also draws designers attention to a number of side-effects of a closer consideration of shape and form, including, effect of solar gain, daylighting, ventilation strategy.