High-performance construction details manual Everything you ever wanted

16 November 2020 by Jason Quinn

Update – the full version of the HPCD Handbook (not manual in the end) is available on the PHINZ website at: https://passivehouse.nz/hpcd-handbook/
The below is the original text with only the link changed to match to the new version of the HPCD Handbook as the draft is no longer available.

I have another book in the works and you have a chance to comment on (or at least check out) the draft.

Unlike my first book, this is a technical manual of high performance construction details. It’s also a solid team effort of BRANZ/PHINZ/Resilienz and our firm, funded in part by the building research levy and with input from MBIE and Beacon Pathway. The project has been gestational for a while—many of you reading this know something about it—but it’s got bigger and more ambitious as time goes on.There are 101 details like this, spanning elements (1-D details eg walls) and junctions (2-D details with heat transfer calculation and 3-D details, with psi and chi values).

This is not a book that will teach you how to do thermal bridge calculations. It is a library of details that have already been drawn and built so that you have the numbers at your fingertips and can do less analysis and more design work for your clients.

Details include

  • walls
  • roofs
  • junctions
  • slabs
  • roof edges
  • window installs (sills, jambs, heads) in a variety of materials.

I repeat, these are not fictional details (with the exception of a couple of the junctions done for comparison purposes). They come from actual buildings that exist in New Zealand. I certify all New Zealand Passive House buildings and some in Australia: that is a lot of drawings over my desk. I went through nearly 100 buildings, looking at different details and chose the best ones. Then folks from MBIE and BRANZ picked which 101 would make it into the book.

Originally, this was to be a manual of Passive House details, for Passive House designers. It now also includes details of current practice: you know, the so-called Acceptable Solutions from the Building Code. This increases the audience for the book. While it wasn’t the point, it does also make very clear how poorly these work compared to high-performance components. This is particularly the case with windows and slab edges.The other upgrade is including cost and carbon accounting for each detail. This is not my area of expertise and that data will be contributed by the folk at Resilienz. Expect the book to be available early in autumn. It will be worth the wait.

The development of those numbers has huge implications for how we build, given MBIE’s climate change team have carefully but clearly signalled step changes to the Building Code. That will require a steady decrease in the amount of operational and embodied carbon in our building sector. That has to mean more timber and less concrete and less steel, at least as currently used in New Zealand.

There are two types of readers: those whose eyes glazed over at the first illustration and those of you who are still reading, who are asking in tones of urgency, where can I look at this thing of wonder and beauty?

You can download and review the draft details from the PHINZ website.  <note this directs to the released version now> Please do this. If you’re qualified to understand the drawings, we want your input. How can we make this resource better? In particular, what cautions can you offer? Do you have practical experience you can share? Have you had problems or successes in specifying one of these details, or building it? If this detail were from a set of drawings for your best mate’s house—or your mum—what advice would you give? And if you have a detail that you think is better than what is currently included, I want to hear about that too. All comments will be logged and reviewed if sent to <snip deleted as this project is complete>

You don’t have to be a PHINZ member to access the draft document but to any readers who are not already members, I strongly appeal to you to join up. PHINZ sought the funding and have managed the project and without the board’s initiative and hard work, this project would still be on my ‘great ideas for the future’ list.

PHINZ is a not-for-profit that runs on the energy of dedicated volunteers who want to see New Zealanders live and work in healthier, more efficient buildings. Support the kaupapa by joining. (New tiered memberships have just been introduced, including an option for students/graduates/retired/unwaged.)

Lastly, if you are a supplier of high-performance building components and want to have details that show how your specific products performs, we now have a very efficient process for developing those. Get in touch to discuss further.