Insulating existing buildings – the rational choice

by Tania Wannenburg
Insulating existing buildings

Though it is not law, existing buildings can benefit significantly from retrofits with an energy-efficient objective.

While it is not yet mandatory to make existing buildings operate more efficiently, within the energy-efficiency net there are compelling benefits for such retrofits.

New buildings and some renovations must already comply with the National Building Regulations (NBR) Part XA, as promulgated at the end of 2011, which regulates the designed energy efficiency of most building occupancy types. However, as existing building stock falls outside the stipulations of the NBR, it will be many years before all buildings are rebuilt with energy-efficient operation as an objective.

In the absence of regulation, interventions would typically be based on rational incentives, with benefits exceeding costs.

What can existing building owners do?
Though there might be opportunities available for both commercial and residential building owners to introduce energy-efficient interventions, the benefits must be significant enough to motivate such actions.

Many national retail or high-profile institutions will inevitably improve their buildings to uphold brand image and corporate objectives, whereas other building owners and users will have a cost versus benefit focus.

Our advice: Thermal comfort
Considering building insulation, IsoBoard recommends that insulation is introduced to the point where it makes a tangible difference to the comfort of building users, or to the costs of heating or cooling the space.

Where people are the main focus of the building, maintaining a comfortable environment is the primary driver of energy efficiency, reducing the need for energy-hungry heating and cooling interventions. Most people feel comfortable in the temperature range between 20°C and 27°C.

Adding insulation to an existing building
To achieve the comfortable temperature range, a thickness of 40mm IsoBoard installed within the roof or as a ceiling will reduce heat flow inward and outward, with minimum heating or cooling. Adding additional thicknesses of insulation may make the internal temperature more consistent, but without actually raising or reducing the temperature.

Where required, IsoBoard can be fixed to exterior or interior walls, and plastered or lined to protect the installation. IsoBoard can also be fitted externally around foundation perimeters to achieve a similar effect to insulate the floor slab. Using a thickness of 30mm, IsoBoard will generally increase the slab temperature between 4°C and 7°C, thereby reducing the use and running costs of any under-floor heating system.

Any flat-topped building with a concrete roof slab will benefit from having IsoBoard installed above the waterproofing layer in an inverted roof application. With its excellent water-resistant properties, IsoBoard is also an ideal solution for green roofing applications.

Should you have a pre-2011 building which you believe could be more comfortable and energy efficient, contact IsoBoard to discuss retrofit opportunities.

Isofoam SA (Pty) Ltd
Tel: 021 983 1140
Website: www.isoboard.com

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