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"we specialise in delivering thoughtfully crafted residential architecture"

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Image credit @ Passivhaus Institut


Creating buildings with outstanding energy efficiency, thermal comfort, indoor air quality.

Atelier Umbra is a design practice creating beautiful & functional homes. We are proudly Passive House accredited and enjoy collaborating with health and future-conscious people looking to build or renovate.

Our motto may be simple; whatever we create will outlive us and contribute sustainably and functionally for its occupants and for

generations to come.


Passive House is not only one of the world’s leading energy efficiency standards but also a construction concept made to build comfortable, environmentally friendly and affordable homes and buildings.

The design is focused on making best use of the “passive” influences in a building – like sunshine, shading and ventilation – rather than active heating and cooling systems such as air conditioning and central heating. Coupled with very high levels of insulation and airtightness, this makes it possible for a passive home to use 90 percent less energy1 than a typical dwelling.

Passive House homes and buildings offer superior indoor comfort due to consistent temperatures and good air quality. They also have the added benefit of reducing both external and internal noise due to the high levels of insulation.


  • Improves quality and lifespan of a building

  • Improves indoor air quality and comfort

  • Significantly reduces energy consumption


Passive House is a voluntary building standard that is energy efficient, comfortable, affordable and ecological. The Passive House standard was developed in Germany in the 1990s and is based on comprehensive building physics and is therefore adaptable for all climates. A Passive House is not confined to residential buildings, either – the standard has been successfully applied to office buildings, schools, kindergartens and supermarkets.

Currently, there are over 60,000 Passive House standard units worldwide and in recent years has grown immensely in popularity in The Netherlands.

There are five fundamental design principles to achieving a Passive House

  1. Airtightness

  2. Thermal insulation

  3. Passive House windows

  4. Ventilation strategy – typically with a Mechanical Heat Recovery Ventilation unit

  5. Thermal bridges minimised

Passive house buildings have extremely efficient building envelopes, ensuring the indoor temperature remains at a comfortable 20-25°C annually, and with minimal (or zero) space heating and/or cooling.


An essential part of every Passive House is an air tight building envelope. This ensures that there are only a very limited amount of gaps and cracks within your envelope, giving you full control over your internal environment and significantly improving thermal comfort – no more draughts!


Sufficient insulation is what’s needed within the building’s envelope, providing enough thermal separation between the heated or cooled conditioned inside environment and the outdoors. This improves thermal comfort and reduces the risk of condensation (no more cold internal surfaces in winter!).


It’s not just the solid areas of your building envelope that need to have good levels of insulation but your windows too. No more single glazing, but instead low-emissivity double or triple glazing with thermally broken or non-metal frames. The size of the windows should be appropriate to each orientation, to allow solar radiation to penetrate during the winter months (free heating!) but not result in too much solar radiation during the summer. Watch out for how well they’re sealed too, as leaky windows just won’t do.


The incorporation of a mechanical ventilation unit means that you don’t need to rely on opening windows to achieve good indoor air quality. The unit effectively recovers heat and coolth that would otherwise be wasted whilst also filtering the air that’s coming into the building. This leads to fewer pollutants in the air and a lower risk of condensation meaning a healthier indoors.


The insulation not only needs to be sufficient in thickness but also needs to be continuous. This means keeping penetrations through the insulation to an absolute minimum, and if not avoidable then using materials that are less conductive to heat (i.e. timber in place of metal) and/or incorporating thermal breaks (whereby a material that doesn’t conduct heat well separates the two conductive elements). Otherwise your wonderfully insulated building will have a number of thermal highways that will cause increased energy consumption and increased condensation risk whilst impacting thermal comfort.

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