DTS method used for a Section J energy report is cost-effective and fast. At Energy Compliance Consultants, we recommend the DTS solution first as it is low cost. However, as this method is prescriptive and not flexible, which may pose challenges to the construction of some buildings. In such cases, achieving compliance using DTS method may increase construction costs (e.g. adding insulation to an existing slab). Also, this method may be highly undesirable to adopt due to aesthetic limitations. To overcome such cases, there are other pathways to help reach a favourable solution, such as JV3 Performance Solution method.
Although Section J reports provide a fast, simple and straight-forward NCC Section J compliance, they have some potential drawbacks:
- Rigidity: Deemed to Satisfy requirements are very strict and must be followed with no exception. For instance, if for aesthetics reasons, the client wants to have an exposed rammed earth wall, under the DTS method, that wall would still need some insulation.
- High glazing ratio: Fully glazed walls typically don’t pass the Section J glazing requirements. In cases that they do, the glazing gets very expensive.
- Isolation: The Section J report assesses building fabric components as individual items and doesn’t consider the holistic performance of the entire building.
- Sustainability limitation: When a council asks for an ESD report, you must go beyond DTS (e.g. 10% better than the DTS provisions). Therefore, DTS pathway may not be achievable using typical glazing or insulation available in the market. In these situations, you must use alternative methods of energy compliance instead of DTS.