The Bad, Better and Best of H1 Compliance: Schedule, Calculation, or Modelling method

This blog assumes you have a basic knowledge of how the code works; if you want a refresher, please read through our other blogs here. Also note that this blog covers H1/AS1 (Acceptable Solution). There are other methods of demonstrating H1 Compliance without using an acceptable solution, but these are rare.

What are the three different methods of H1 compliance?

The three different methods of H1 compliance are as below:

  1. The Schedule Method (table)
  2. The Calculation Method (simple online calculator)
  3. The Modelling Method (software)

 If you try to “see” your building’s energy use as a photograph, the Schedule Method is like a useless picture with 4 enormous pixels. The Calculation Method is slightly better but still you couldn’t tell what the picture was… the Modelling Method is the only one which gives you a clear picture. 

Schedule Method – The Bad

Schedule method H1/AS1 Compliance is not only the most expensive to build, but it guarantees that your envelope is overengineered, and at significant risk of overheating. You essentially have no idea how the building will perform, all you know is that it’s expensive.
Historically, most builders, architects and specifiers defaulted to the schedule method, because it has been the easiest. That is no longer the case!

  • Guaranteed to be over-engineered.
  • Most expensive use of building materials.
  • Highest embodied carbon.
  • Highest operational carbon.
  • R6.6 in ceiling risks overheating

Calculation Method – The Better

Calculation method is MUCH easier than you thought – thanks to the wonderful online tool here,  You just need a few basic numbers, pop them into the calculator, and Voila! You can then save as a PDF and submit to council with your plans.  We at Starke can give you some simple training on this (if required)!

By using the Calculation Method, we have found that for many residential builds in Auckland, you don’t need to change your ceiling, you don’t need to change your walls, you don’t need to change your floors. All you need to do is use STARKE Ambiance  windows with a good low-e glazing, and that will likely give a pass.

For the R-value of the windows, we recommend putting in R0.74, for STARKE Ambiance  and a Low-E of U1.1. 

  • Value-engineer the envelope
  • With STARKE Ambiance & Low-e, often does not require any other changes
  • Spend money only where you need to
  • Minimise embodied carbon
  • HOWEVER – you still don’t know how the envelope will perform, and it won’t prevent overheating. 

Modelling Method – The Best

Modelling method is the only H1 compliance method which really tells you how your building will perform, warns of negative building outcomes, and which factors in the very real risk of overheating. Modelling method has historically been somewhat difficult and expensive, but we are on a mission to change that; which is why we now offer cost-effective envelope modelling to all of our clients.  It’s low-cost, and fast. 

Starke can prepare a report showing building energy usage for heating and cooling throughout the year, warn of over- or under-temperature times, and include H1 compliance pathways for Schedule, Calculation & Modelling; and of course recommend the most effective joinery & glazing spec to optimise the performance, for example solar heat gain blocking glazing to north & west elevations, and areas of the building envelope in which you can save.

  • Be warned of & prevent negative building outcomes (overheating)
  • Value-engineer the envelope factoring heat loss AND heat gain
  • With STARKE Ambiance & low-e, unlikely to need many changes to the way we currently build
  • Save significantly on building material money & carbon consumption by building the most efficient envelope. 
  • Low-cost & fast to model

OK great…! What’s Next?

Please send your plans to, and let us know the below (if known)… and we’ll do the rest!

  • Thermal performance requirement of the building – ie. code minimum, Homestar, low-energy building, Passive House etc.
  • Preferred Compliance Method
  • Project dates & timelines
  • Estimated joinery budget
  • Anything else out of the ordinary on the project we should know about!

Window R-Value Interactive Table

The below chart contains window & glazing combinations & their respective R values  – you can sort and filter to choose the best combination of frame and glazing for your project. The data shown is as per the New Zealand Building Code H1/AS1, Table E1.1.1.

FrameGlazing TypeR-Value
AluminiumUg 2.63 Clear/Clear (Air) (Double)0.26
AluminiumUg 1.9 LowE1/Clear (Argon) (Double)0.3
AluminiumUg 1.6 LowE2/Clear (Argon) (Double)0.33
AluminiumUg 1.3 LowE3/Clear (Argon) (Double)0.35
AluminiumUg 1.1 LowE4/Clear (Argon) (Double)0.37
AluminiumUg 0.9 LowE4/Clear (Krypton) (Double)0.4
Thermally Broken AluminiumUg 2.63 Clear/Clear (Air) (Double)0.32
Thermally Broken AluminiumUg 1.9 LowE1/Clear (Argon)(Double)0.39
Thermally Broken AluminiumUg 1.6 LowE2/Clear (Argon)(Double)0.42
Thermally Broken AluminiumUg 1.3 LowE3/Clear (Argon)(Double)0.46
Thermally Broken AluminiumUg 1.1 LowE4/Clear (Argon)(Double)0.5
Thermally Broken AluminiumUg 0.9 LowE4/Clear (Krypton)(Double)0.5
Thermally Broken AluminiumUg 1.89 Clear/Clear/Clear (Air) (Triple)0.38
Thermally Broken AluminiumUg 1.2 LowE2/Clear/Clear (Argon) (Triple)0.48
Thermally Broken AluminiumUg 1.0 LowE3/Clear/Clear (Argon) (Triple)0.52
Thermally Broken AluminiumUg 0.7 LowE3/LowE3/Clear (Argon) (Triple)0.59
Thermally Broken AluminiumUg 0.6 LowE4/LowE4/Clear (Argon) (Triple)0.62
uPVCUg 2.63 Clear/Clear (Air) (Double)0.4
uPVCUg 1.9 LowE1/Clear (Argon)(Double)0.5
uPVCUg 1.6 LowE2/Clear (Argon)(Double)0.56
uPVCUg 1.3 LowE3/Clear (Argon)(Double)0.63
uPVCUg 1.1 LowE4/Clear (Argon)(Double)0.69
uPVCUg 0.9 LowE4/Clear (Krypton)(Double)0.76
uPVCUg 1.89 Clear/Clear/Clear (Air) (Triple)0.5
uPVCUg 1.2 LowE2/Clear/Clear (Argon) (Triple)0.66
uPVCUg 1.0 LowE3/Clear/Clear (Argon) (Triple)0.73
uPVCUg 0.7 LowE3/LowE3/Clear (Argon) (Triple)0.86
uPVCUg 0.6 LowE4/LowE4/Clear (Argon) (Triple)0.91
TimberUg 2.63 Clear/Clear (Air) (Double)0.44
TimberUg 1.9 LowE1/Clear (Argon)(Double)0.56
TimberUg 1.6 LowE2/Clear (Argon)(Double)0.63
TimberUg 1.3 LowE3/Clear (Argon)(Double)0.71
TimberUg 1.1 LowE4/Clear (Argon)(Double)0.77
TimberUg 0.9 LowE4/Clear (Krypton)(Double)0.85
TimberUg 1.89 Clear/Clear/Clear (Air) (Triple)0.56
TimberUg 1.2 LowE2/Clear/Clear (Argon) (Triple)0.74
TimberUg 1.0 LowE3/Clear/Clear (Argon) (Triple)0.81
TimberUg 0.7 LowE3/LowE3/Clear (Argon) (Triple)0.95
TimberUg 0.6 LowE4/LowE4/Clear (Argon) (Triple)1.01