E&V Potchefstroom: Going Green part two

Going Green

Lekwena Lifestyle Estate – Potchefstroom

With ‘Green’ at the top of everyone’s mind in an effort to save our environment and at the same time saving costs, Engel & Völkers Potchefstroom started their green initiative by building the first green, energy efficient house in the area at Lekwena Wildlife Estate in Potchefstroom.

The building progress will be monitored and we are taking you through the process step by step. In part 1 we have covered the location and focused on green activities for optimal use of the environment and preserving the natural surroundings. If you missed this, please visit www.nationalguidetorealestate.co.za and browse to page 38 of Edition 06/2014.

The six principal factors that contribute to the sensation of thermal comfort are:

  • Air temperature
  • Radiant temperature
  • Humidity
  • Air movement
  • Metabolic rate
  • Clothing levels/insulation


Going green

How heat escapes in winter


“In doing our research for Project Green and with the designing of our energy efficient house at Lekwena Wildlife Estate in Potchefstroom we realised the significance of this next step, namely insulation,” says Carl Venter, License Partner of Engel & Völkers Potchefstroom. The ideal is to design and insulate the house in order to get a thermal passive shell. A lot of the heat that we spend hours, vast amounts of money and electricity on to create in winter, just gets lost into thin air…Well, technically it is  lost through our roofs, floors, windows, doors and walls – basically every part of our home which is not insulated.

We quickly realised that a little insulation can go a long way in creating a welcoming and warm interior during winter or a cool and comfortable interior during summer.

In summer months warmth can easily be absorbed, if your home is not insulated.

  • Through your windows 25 – 35%
  • Leakage through a ceiling can gain an extra 25 – 30% heat.
  • Through your walls 15 – 25%.
  • And 25 – 35% through the doors and windows due to air leakage.
Going Green

How heat gets trapped in Summer


In winter months the tables are turned and heat is lost in an uninsulated home.

  • 25 – 35% through windows.
  • 25 – 30% through your ceiling.
  • 15 – 25% through walls.
  • 15 – 25% lost through air leakage through the doors and windows of your home.
  • And an additional 10 – 20% of heat lost through your floor.


Devilliers du Toit Architects – our green expert and architect of the project – aims to insulate the Green House at Lekwena Wildlife Estate very efficiently in order to minimize the heat transfer and to keep the house comfortable both in summer and winter.


Potchefstroom is located in climate zone 1 – with ‘Cold Interior’ climatic conditions which mean that our main problem lies in keeping the Green House warm during the cold winter months.


Insulation that will be implemented in the Green House:

  • Floors: Polystyrene is one of the products considered to insulate the floor
  • Walls: Using good quality clay bricks and will apply additional insulating methods in the walls. Innovating building methods are also considered.
  • Ceiling: There are currently various options available to replace conventional ceiling boards including PVC, polystyrene and more advanced products. Additional insulation products will also be used in the ceiling.
  • Doors & Windows: To minimize air leakage, smartly designed aluminium frames with additional insulation features will be investigated.
  • Glass: Since 25 – 30% of heat can be lost or gained through windows, the type of glass will be chosen  carefully and double glazing will be added in rooms where needed.
  • Roof: To curb heat transfer through the roof, the roof will comprise a high quality sheet metal product with a reflective colour.


In our research journey to find the most optimal insulation products we will only use insulation products that are accredited with TIASA – the Thermal Insulation Association of South Africa.



Our Sources:

Elements of comfort paper by T.van Reenen, senior researcher at CSIR.

Eskom. www.eskom.co.za

Thermal Insulation Association of South Africa. www.tiasa.org.za