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  • HPH190 : How we are specifying our self build project – with Ben Adam-Smith

    HPH190 : How we are specifying our self build project – with Ben Adam-Smith

    Ben Adam-Smith explains how he and his wife have been specifying their new home (which will be built to Passivhaus standard).

    Ben looks at the decisions that they have made themselves and those which have been dished out to the team.

     

    Decide how involved you want to be

    This is a decision that you have to make right at the start when you select your build route. My wife and I opted for the contractor route, which should be the easiest but also the most expensive.

    For us, the essence has been on having a good experience because we have a young family and our time is precious enough as it is.

    That said, there are still plenty of decisions to be made!

     

    Be guided by the best team you can afford

    While we have made lots of decisions on this project there are also many which we have delegated.

    There is no way we would have the confidence to do this unless we believed in our team.

    This started with hiring the right architecture firm but has also included other specialists (such as an interior designer, M&E engineer, and garden designer).

    We always aim to understand why decisions have been made but there have been a few times where it’s got too technical!

     

    Tender documents need detail to be meaningful

    If your build route will see you go out to tender to a small number of builders, then you will need to make as many decisions upfront as you possibly can.

    It is possible to say things like ‘allow £3000 for a bathroom’ but there’s more risk doing this than if you choose your bathroom products and materials, get them priced up and then don’t change your mind.

     

    A house can be broken down into its constituent parts

    Specifying a house is a huge task for a first-timer, so it can be broken down into manageable chunks.

    For example, the headings might include structural system, electrics, mechanical and plumbing systems, the internal and external doors, the windows, floor finishes, etc.

    You can then go into another level of detail. So for electrics, that might consider the numbers and positions of light fittings, light switches, socket outlets, telephone points, ethernet and data points, smart systems, TV, alarm and so on.

     

    Clear your diary during the technical design phase!

    Self builds do not progress in a linear fashion. There are fits and starts. Specification is definitely one of these.

    Once our architects were focusing on this stage, they moved quickly.

    Kay was really good a responding to emails in a timely manner and trying to bat the ball back into their court.

     

     

     

    Watch Mike Coe’s video

    Former ITV News cameraman Mike Coe is embarking on his second self build in Portree, Scotland.

    This time around he’s going to be providing regular video reports on his project progress.

    However, his first report looks at why he and his partner Lizzie decided to leave their ground-breaking autonomous house to move further north.

    The answer is comprehensive to say the least . . . and has turned into a 50-minute documentary! It sums up problems with UK house-building and why the issue of climate change is not being tackled adequately.

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  • HPH186 : Choosing windows for a Passivhaus home – function versus aesthetics

    HPH186 : Choosing windows for a Passivhaus home – function versus aesthetics

    Ben and Kay Adam-Smith have a difference in opinion over which windows to specify for their new build Passivhaus home. While Ben is keen to minimise mullions, transoms and window frames, Kay believes this takes away from the aesthetics of the building.

    A visualisation of Ben and Kay’s house

    Today’s episode is really a short story about aesthetics. Life would be boring if we all liked the same thing. However, what happens when you’re working with your other half on a self build and you strongly disagree about something? How do you move on? Well we haven’t answered that one yet, but we can share the disagreement and let you know what happens over the course of time!

    I (Ben) also feel like I might have said what my wife is saying a few years ago. I believe I’ve grown in my understanding since then and so now my opinion has changed.

     

    Mullions, transoms and window frames

    Firstly what are mullions and transoms? Well, they are the structural elements that divide up sections of a window. Mullions are vertical while transoms are horizontal.

    There’s no denying that the use of mullions and transoms can make some beautiful windows (as in the stained glass window above, where it’s taken to an extreme).

    In the past it was just not possible to manufacture large single pieces of glass and so to achieve a big window, a number of small ones needed to be ‘stitched’ together.

     

    Large glazing is now possible

    Probably a window’s most important function is to provide that visibility from one side to the other.

    Windows without mullions and transoms therefore do a better job of connecting the inside to the outside (and obviously bring in more light).

    As we spend 90% of our time indoors, you could argue that the view out is more important than the aesthetic appearance of the window from the outside.

     

    Large single pane windows are still not the norm

    In a country where our period properties make up a large proportion of the housing we live in today, it is hardly surprising that we gravitate towards their features.

    That’s perhaps why Kay would like two of three ‘lights’ (subdivisions) in each window.

    She also thinks that a lot of houses that use large panes of glass just don’t look right; they look like they need to be sub-divided.

     

    Reducing the amount of glazing in a window affects its performance

    The frame is generally the weak point of the window.

    Chris Parsons of Parsons + Whittley says: “We want more glass and less frame in the way, because the more glass we have the better the performance of the window. When you start dividing them up with mullions and transoms, you now can’t insulate that part of the frame by wrapping anything around it.”

    How much glass is actually in a window?

     

    PHPP models the amount of glass and the amount of frame

    Even if a window has a good central pane U-value (a measure of how effective it is as an insulator), it is only referring to the glass. Therefore the Passive House Planning Package (PHPP) requires information on both the amount of glass and the amount of frame in every window. This is the only way to produce an accurate model of the thermal performance.

     

    The ease of opening and closing windows depends of their size

    While performance is important when creating a Passivhaus, it must also be balanced with practicality.

    When windows get too big, they take a bit more manoeuvring so this could become a valid reason for introducing different lights in certain windows.

     

    Aesthetics will always be a key driver in window choice

    There is no doubt that windows with mullions and transoms produce a pretty pattern on the window.

    It is also possible to get Passivhaus sash windows, for example. However, for new build, does it make sense to specify sash windows (given all the arguments above)?

    This is a choice you’ll have to make . . . and a choice we have to make on our build!

     

    Keep an open mind

    This can be a great attitude to anything in life and it’s just the same with architecture.

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