Joyous buildings

Recently, I had the opportunity to meet Richard Hawkes, whose very attractive house Crossways appeared on an episode of Grand Designs last year. His project has just gained Passivhaus certification, which is great. Congratulations!

When I met Richard and on his blog, he expressed his belief that the PHPP is a block to creating "joyous" buildings and, now that he has certification, that the PHPP is redundant. Indeed, the PHPP seems to be generally a Bad Thing; as well as interfering in the creative process, it is antithetical to collaborative working.

I am amazed that the PHPP, which is after all just an Excel spreadsheet, albeit a very sophisticated one, has such power over architects, builders and others working in the built environment that it can prevent them from producing beautiful designs or working collaboratively. My experience as the client and Passivhaus designer during the design phase of our project does not bear this out. We have found the PHPP to be a very useful tool in helping us to optimise our design, for instance by not over spending on unnecessary insulation or by focussing our attention on detailing critical areas correctly. However, the PHPP does not design the building for you. It is still up to the architect to use their creativity and experience to deliver a building that uplifts, that is "joyous". It is still essential to work collaboratively on the project, indeed collaborative working between client, architect and the builder (who should be identified and involved early in the project) is probably the most important success criterion in a Passivhaus project. The PHPP is merely one of the tools in the design tool-kit.

We have been more constrained by other factors, primarily by the fact we are refurbishing an existing property, rather than building from scratch. Also, our house is on an estate with a strong architectural character and it is this, other site constraints, financial constraints and the requirements of the planners that are driving our design, not the PHPP!

I think that Richard is right when he talks about experience. The Passivhaus design process uses a lot of rules of thumb, derived from many years' collective experience, to get the initial design broadly correct; this is something that an experienced, certified Passivhaus Designer can bring to a project. Having produced an initial draft of the plans informed by those rules of thumb, the PHPP is there to help to highlight potential problems in the design. It is still up to the architect, Passivhaus Designer, client and builder if they want to aim to use the PHPP to achieve Passivhaus certification. They may decide that a particular aspect of the design is more important than reaching the full certified Passivhaus standard. Using the PHPP properly means this decision is a concious one, rather than an unintended error. In that scenario, the PHPP can sometimes help identify other areas where the shortfall can be made up elsewhere in the design. In a world where Passivhaus design is the norm and understanding of Passivhaus design and methodology has been widespread for decades and is embodied in the DNA of all the professions working in the build environment, the PHPP would probably become considerably less useful. However, particularly here in the UK, where we are very far from this, the PHPP will remain a useful tool for a long time.

I would add that in a refurb, where nearly every project needs a bespoke design, the need for the PHPP is even greater. In a new build, provided that client, architect and builder have that "Passivhaus DNA", whether or not they would recognise it as that, and particularly in the less challenging (meteorological) climate of southern England, Richard Hawkes has shown that it is possible to reach certification. However, I wonder whether he could not have trimmed some elements of his design* and saved himself a bit of money by using the PHPP tool earlier on.

* I am referring to those relevant to the building's energy performance, not those that make it "joyous"

[edit 27 Jul] This recent article on the Centre for Alternative Technology's new WISE building continues the debate.

A radical renovation

Welcome to my blog! I hope it will be informative and entertaining. If you are planning any changes to your home, whether or not motivated by environmental concerns, there should be something of interest here for you.

We are about to embark on a very challenging journey to convert our leaky, draughty, unrenovated 1970s home into a certified Passivhaus: a house that needs no active heating or cooling systems to maintain a comfortable indoor temperature and a healthy indoor air quality, all year round.

The project and this blog are intended to be about more than just eco-renovation. In fact, I want to avoid using the "E" word and the "C" word (carbon) as much as possible, as they have both become clichéd. Even if you are one of those who apparently doesn't "believe" in climate change or peak oil - both of which are significant motivators for me to take on this project - most of you would still want to live in a comfortable, cheap to run home, so read on. That said, implicit in this project is an understanding that we are moving into an era where energy is much more expensive and increasingly less freely available than most of us have been used to.

In the blog, there will inevitably be a certain amount of jargon. I'll try to make sure I explain any technical terms when I first use them.

What do we want to achieve?
Put simply, we want to create a comfortable home that is very cheap to live in and to maintain; a house that will meet our needs for the whole of our lives. It will also be a house with a low environmental impact.

Why a renovation and not a new build?
Here in the UK, building plots, particularly where we live, are scarce and expensive. It is a practical choice for us, given our other constraints. Renovations are important because most of the buildings we will be using in 2050 already exist today; renovating our existing housing stock is inevitable. Each renovation is an opportunity to reduce the building's future running costs by reducing its energy use.

What is a renovation?
The word renovation covers a wide spectrum of repair and modernisation work. It could just mean fitting new cupboards and appliances in your kitchen, re-painting inside and out and re-fitting the bathroom with a new suite from the DIY centre. All superficial changes intended to make the property more attractive. Here we are looking at a much deeper renewal, replacing and augmenting elements of the building that many renovations leave untouched. In our house, the roof, windows, external walls, doors and all services need replacement or repair.

Where have we got to so far?
I guess the project started a couple of years ago, when we started looking for a house or a plot. We chose with a keen eye on what type of property we thought would lend itself to Passivhaus renovation. We decided to live in the house as is, partly to get to know it before making any changes. There is quite a lot about the house that we like and it often takes a while to tease out what changes really are needed.

A Passivhaus is different from most building projects, as a lot of thought must go into some detailed design considerations at the beginning of the design stage. Because of this, it is very hard to convert a non-Passivhaus design into a Passivhaus one later on in the design process. We have been working with our architect on these: the two areas that are most challenging are the floor and exterior walls.

The construction of our house is typical of many built in the early 1970s. It has two leaves of dense concrete blockwork and a concrete slab of concrete (reinforced?) covered by about 70mm of screed. The ceiling heights are not particularly generous, so we cannot increase the finished floor height significantly. The 50mm wall cavity is filled with mineral wool. We will be cladding the walls with external insulation and a rendered finish to match what we currently have. This is because the house is on an estate of similar properties and we want our house to retain its "group identity", as will the local planning officers!