Architecture is often described as the combination of art and science. The role of art in architecture is understandably subjective and open to debate. However, what about the role of science in architecture?

Clearly buildings do obey the laws of science, as they must. And specifically, the structure and services of a building are calculated and designed using physics. Understandably, it is most often these areas of science that get expressed in architecture. We can see this, for example, in the structural expressionism of Santiago Calatrava or in the romanticised high-tech style of Richard Rogers.

Aside from structure and building services, however, does science inform architecture in any other ways? Perhaps not as often as it should! As I wrote about previously, design is central to passivhaus. And science is central to passivhaus design – at the macro level of form and orientation, and at the micro level of airtightness and thermal bridging.

Science is a reason to Love Passivhaus!

020 Love Passivhaus Science

Love Passivhaus: Science, Orientation and Form

Science and Orientation

Solar orientation has an enormous impact on the energy and comfort performance of a building. This is not to say that passivhaus architecture must rigidly face the equator to maximise solar gain. Rather, it means that the impact of the orientation, along with the glazing design, can be calculated. The science of this is built into the Passive House Planning Package (PHPP) so the impact is known during the design process.

If the orientation of the building is restricted by site constraints, the impact can be checked. Equally if the site offers opportunities for desirable spatial relationships or views, the impact of orientating the building to suit can be checked.

Science and Form

Shape and form also have an enormous impact on the energy and comfort performance of a building. Particularly, the amount of external surface area in relation to the internal floor area has a great impact. (The Heat Loss Form Factor.) More external surface area or more complex shapes will lose more heat and energy through the fabric.

This does not mean that passivhaus architecture must be plain rectangular boxes, although there is “Boxy But Beautiful” architecture. Rather, as with orientation, it means that the impact of shape and form can be checked.

Passivhaus brings science into the heart of the design process so informed design decisions can be made.

Love Passivhaus: Science, Airtightness and Thermal Bridging


Airtightness is very hard to test at the design stage. It needs to be thought through and incorporated into the design and detailing very carefully. And then ultimately workmanship on site determines if the building fabric is actually airtight. This can and must be tested. The Passivhaus Standard requires pressurisation and depressurisation tests are carried out using a blower door to ensure the building fabric is airtight.

This is rigorous process whereby science is used to quantify how airtightness of the building fabric. It also provides a precise measure of the construction quality. Airtight building fabric is not only energy efficient and comfortable, the structure is protected from damaging moisture ingress.

If you haven’t yet seen the short documentary “The Future of Housing and How Airtightness Can Help” by Ben Adam-Smith of House Planning Help, I highly recommend you watch it. It makes the subject of airtightness incredibly accessible and you will realise just how important it is. (Disclosure: I had a minor involvement in the production of the documentary.)

Thermal Bridging

Thermal bridging can and must be checked thoroughly during the design process. Once it gets to the construction stage it is almost certainly too late! The aim is for passivhaus buildings to be thermal bridge free. However, in reality there are often some unavoidable thermal bridges. Once these are identified, they must be modelled and accurately quantified for entering into the PHPP.

Thermal bridging and the impact it can have on energy and thermal performance is often underestimated. (Or ignored!) The passivhaus methodology has the right science built in so that this doesn’t happen.

Passivhaus uses science to ensure quantified building quality and performance.

Love Science: Love Passivhaus

Science is always there and buildings always obey the laws of physics, whether they are consciously designed to do so or not. The consequences of ignoring science in architecture are very real – uncomfortable buildings that guzzle far too much energy and emit far too much CO2 into the atmosphere. Ignoring science also means promises aren’t be kept, buildings don’t perform as predicted.

Passivhaus makes accessible the important aspects of science that impact on building performance. Science becomes an important and conscious part of the design and construction process. And the impact of design decisions are reliably and accurately quantifiable. Promises are kept.

Passivhaus architecture truly can be a marriage of art and science. And this is what the world needs in the anthropocene – architecture that consciously works with the laws of physics. Architecture that performs as it should. Passivhaus architecture.

This blog post is part of a series of posts on reasons to love the Passivhaus Standard – in contrast to the tongue-in-cheek post ‘10 Things I Hate About Passivhaus‘ which you may have already read. The #LovePH series was prompted by the inaugural South Pacific Passive House Conference and Trade Show taking place in Auckland, New Zealand, over Valentines weekend 2015. I was privileged, both as a Kiwi expat and as a passivhaus architect and enthusiast, to be invited to give a presentation at the conference, on behalf of Architype Ltd where I used to work.

Please join in and share on social media what you love about the Passivhaus Standard using the hashtag #LovePH.

For more posts on reasons to ‘Love Passivhaus’ and to learn more about passivhaus related topics, please subscribe by email at this link.