Passive Solar Design & Passivhaus – What’s the Difference?


Passive Solar Design & Passivhaus – What’s the Difference?


Passive Solar Design, Sustainable Design, Passivhaus, Energy Efficient design – these are often terms loosely thrown around as ‘buzz’ words in the construction industry without knowledge of their proper meanings. Here we take a closer look at these concepts and provide some needed clarity for those wanting to build an eco-friendly home that reduces the negative impact on their health and the environment.


– is a holistic approach to the overall process of creating a home. It focuses on solving problems but takes an approach which sees systems as an interconnected whole that is part of a larger world. How materials used in construction are sourced and processed, their re/up-cyclability, and the embodied energy of manufacture – right through to the building design process and the use and performance of the home as a shelter for the inhabitants, are all considered.  The lifespan of the materials in the form of an actual home, as well as demolition and recycling opportunities, and the recovery of materials is also important.

Other factors could include:

  • The location of the home – will it allow for less travelling by car?
  • Water sensitive landscape design – as a mode of protection which also promotes native fauna, bees, and provides productive gardens you can eat.
  • Water resourcing – collecting and harvesting water is considered here. We can discuss rainwater collection and recycling options including the harvesting of grey water and black water with clients.



-is a major part of energy efficient design. The concept is that passive solar design can make up 90% of the overall energy efficiency of your home via building orientation, materials selection, ventilation and air-flow, and the location of living, service and wet areas etc. The term “passive solar” can be somewhat misleading as a passive solar home requires inhabitants to actively operate the home. It’s the use of design solutions that will optimise solar access and maximise energy efficiency that can help homes remain comfortable for longer all year round.

Perth – from Geraldton in the North to Pemberton in the South we experience a Mediterranean climate. The implementation of correctly located thermal mass in our homes becomes important to offset heat gain and heat loss throughout the year. To maximise performance, both horizontal as well as vertical mass are needed.


-defines a home where CO2 emissions are minimised through the incorporation of passive solar principles as well as/or the use of active systems:

  • Solar power – captures the sun’s energy to generate electricity and/or hot water through the use of solar photovoltaic panels on roofs
  • Appliances – enhance the sustainability of your home by using energy efficient appliances (fridge, washing machine, dryer, dishwasher) as well as taps, showerheads, dual flush toilets, gas boosted solar hot water or heat pump systems and battery storage, which can save hundreds of dollars on annual energy and water bills.



-is a technique developed in Germany with a set of rigorous standards set in place to make conventional artificial heating/cooling obsolete, making homes extremely energy efficient. According to the Passive House Institute US, these standards will change depending on the climate in where these homes are built. The German Passivhaus Institute (PHI) believes the standards as set will work in any climate.

The design principles typically used to meet the standard are:

  • Super insulate the building envelope
  • Eliminate thermal bridging
  • Make it airtight
  • Install an energy or heat-recovery ventilator
  • Use high-performance windows and doors
  • Optimise passive solar where appropriate
  • Model energy gains and losses using the Passive House Planning Package (PHPP), a software tool

On average passive houses are reported to be more expensive upfront than conventional buildings.

In summary

Sustainable design involves creating buildings that meet the world’s need to reduce human impact on ecological systems. Custom Green’s integrated approach, utilising technologies, belief systems, and knowledge from the natural and built world, as well as learnings from various industries, provides our clients the knowledge to address sustainability issues without compromising building functionality, aesthetics or budget.

Here at Custom Green, we deliver fit for purpose eco houses in Perth that exceed national standards, ensure the highest quality workmanship and surpass client expectations from concept design through to construction, and key handover.

We will even follow up after you’ve moved in to ensure you’re getting the best performance possible through the operation of your home!

Feel free to contact us anytime on (08) 9479 6828 if you have any questions and we will be happy to help.