As a practice we are fortunate to not only have built the first passivhaus in England, but also lived in it as well, most architects just build them. It gives us a unique incite into the practicalities of life in these houses, but more importantly the joy of living in one of the highest standards of sustainable construction possible. It is not a clinical sterile eco experiment. It is the most comfortable, fresh and warm house we have ever lived in. And despite what people say - Yes you can open the windows when you want to….. but you don’t need too.

Underhill house was designed to meet the German Passivhaus standard. Developed in 1996, five years after the first experimental Passivhaus project, the Passivhaus standard relies upon a very simple set of premises; very high levels of insulation, elimination of cold bridges, super-insulated triple glazed windows orientated to the south to maximise passive solar gain, and an incredibly well sealed building fabric. It also has a mechanical ventilation system to provide excellent air quality and highly efficient heat recovery.

As a result of these relatively simple concepts, the building retains heat from passive solar gain, activities such as cooking, watching television and showering, and uses it to eliminate the need for a central heating system. If we get cold, we’ll have a party, or get another dog…

It is estimated that using the Passivhaus method to construct a typical house results in an 90% reduction of carbon emissions compared to that of an average home. By adding renewables, ours will be carbon neutral.

There are over 15,000 completed Passivhaus projects on the continent. Ours is the first to have been certified in England (certified by the Scottish Passive House Centre in January 2010, on behalf of the Passivhaus Institute).

It’s important to note that Passivhaus does not dictate the design or external appearance of the house. It is simply a method of calculating the amount of insulation, glazing, thermal mass etc. to make the best use of passive solar gain, and ensure that the resulting internal climate will always be comfortable.

Underhill House

Underhill House

Underhill House actually achieved Passivhaus Plus even before the standard was invented because of all of the renewable technologies we designed into the building.

moseley passivhaus

Moseley EnerPHit House

We realise that building new passivhaus’s isn’t going to solve the problems with the existing housing stock and that we need to upgrade existing buildings as well. As part of this we took on the Moseley project near Birmingham. This was a run down 1930’s house in a conservation area and needed completely refurbishing. We took the opportunity to design to the EnerPHit standard (Clients chose not to pay for certifying), which is to retro fit an existing house to as close to passivhaus as possible. The client wasn’t 100% certain the standard would work and installed underfloor heating as well. The last time we spoke to them they still hadn’t used the underfloor heating.

Cheltenham Passivhaus

Cheltenham Passivhaus

Our next two passivhaus’s were medium sized developments. The first was the Cheltenham Passivhaus which was located in a conservation area, creating interesting compromises, but non that effect the passivhaus aspects.

Bulgaria Passivhaus

Bulgaria Passivhaus

Our second passivhaus was the Bulgaria Passivhaus affordable, low energy family house competition, for which we gain 2nd place and received an honourable mention. You can read more about it on the project page


Hitchambury Passivhaus - NPPF Para 55

Moving on from our competition half success and always trying to be the first Hicthambury Farm was the first new NPPF par 55 house to have been permitted in Green Belt that wasn’t a replacement dwelling. The project has also been awarded funding by the Technology Strategy Board for the work being done by Ulster University on the pioneering underground Seasonal Thermal Energy Store which will form part of the scheme.

Not being a practice to rest on our laurels we have been busy researching and designing to the new Passivhaus Premium standard, first announced in April 2014. This standard takes everything from the original standard and moves it forward to achieve the EU’s mandate for all new buildings to be NZEBs (Nearly Zero Energy Buildings) by 2021. So we thought we had better get on and design a house to this standard. We first spotted the Perry Pear Orchard site six months before the new standard came out. The more we looked at the site the more we realised it would be perfect for a Passivhaus Premium project. You can read more about the project on the project page.

Perry Pear Orchard

Perry Pear Orchard - Passivhaus Premium - NPPF Para 55

One of the spin off benefits of specializing in Passivhaus is that not everyone wants to/or can build to Passivhaus on their site. With our specialist knowledge we are able to recommend the systems or technologies that are relevant to the property and advise on the consequences of introducing a new element to a property and more importantly what positive or negative effects it will have on the rest of the property. A good example of this is the Frog Lane project. You can read more about that on the project page