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Acceptable Solution H1/AS1
Our H1/AS1 modelling approach is unique, where the modelling requirements of H1/AS1 are set and reporting is automated. This approach saves significant time and effort, enabling design optimisation to be the focal point. A typical residential building is simulated in less than an hour, including simulations and results.
H1/AS1 outlines two methods for demonstrating compliance: the schedule method and the calculation method, while H1/VM1 employs the modelling method.
Designers using the schedule method must ensure that each building element, such as floors, walls, and roofs, meets or exceeds specific minimum construction R-values. Now, all doors, including opaque ones, must adhere to the window and door minimum R-values, a change from previous regulations where opaque doors had no R-value requirements. The schedule method has certain limitations:
- The glazing area must not exceed 30% of the total wall area.
- Combined glazing on east, south, and west-facing walls must not exceed 30% of these walls' total area.
- The skylight area must not exceed 1.5 m² or 1.5% of the total roof area, whichever is greater.
- Opaque door area must not exceed 6 m² or 6% of the total wall area, whichever is greater.
The calculation method offers more flexibility, comparing a building with a reference building and allowing variations in individual building elements' insulation levels. However, it also has limitations:
- It can only be used where glazing is 40% or less of the total wall area.
- Construction R-values for roofs, walls, and floors must be at least 50% of the corresponding element in the reference building.
- It cannot be used to reduce the performance of slab floors, walls, or ceilings with embedded heating systems.
- E3/AS1 specifies minimum R-values, and the calculation method cannot provide lower values.
Like the calculation method, the modelling method allows flexibility, with the energy use of the proposed design not exceeding the reference building using computer modelling as described in Appendix D in H1/VM1. It has limitations as well:
- Minimum construction R-values apply for heated ceilings, walls, or floors.
- E3/AS1 specifies minimum R-values, and the modelling method cannot provide lower values.
The required minimum construction R-values vary across the country, with colder climates typically needing higher R-values. There are six climate zones, and more details can be found in Appendix C in H1/AS1 and H1/VM1, including a map and table showing the applicable climate zone for each territorial authority.
Last modified 27d ago