National Construction Code NCC 2019 Section J Review

Deemed to Satisfy assessments are generalized assessments of projects whereas Performance Solutions seek more flexible solutions which are more adaptable to the the building design. Hence it is found that Verification Methods and Performance Methods are more cost effective solutions.

The only legally enforceable section of Section J is Section JP1, the Performance Requirement, the other sections are for demonstration purposes.

JV Methods

In NCC 2019, JV3 compliance is proposed to be made more stringed by a number of methods:

Thermal Comfort is proposed to be assessed with verification methods using comparison of PMV figures (reference vs proposed) as a heavy emphasize is placed on constructing comfortable buildings for the occupants.

Greenhouse gas emissions are proposed to be the basis of assessment rather than energy. It is proposed that JP3 which discusses comparative uses of fuel will be deleted.

Currently under the JV method you can compare a reference and a proposed building case.

Two new JV methods are proposed in NCC 2019, one simulation method involving Green Star simulation principles and one simulation method involving NABERS simulation principles. Using Green Star simulation principles, the Reference Building has to be minimum 10% better performing than the proven GreenStar benchmark.

When using NABERS simulation principles, the modelling carried out using the NABERS Commitment Agreement is used to demonstrate a level of performance to demonstrate compliance with the code. The level of performance is currently being determined, typically 6 stars.

If a project is already carrying out Green Star or NABERS simulations, there is no need to carry out additional JV simulations as the project is able to use the results from the earlier simulations to prove compliance with JV.

Thermal Comfort PMV compliance applies to either of the three JV methods (JV3, NABERS, GreenStar).

In NCC 2019, compliance to non simulated items is also proposed as there are various factors which can’t be demonstrated using a simulation.

Insulation

Roof colors are assumed to be light in color.

Levels of insulation requirements are proposed to remain the same, however the Code is proposed to be simplified.

Thermal bridging requirements are proposed to be simplified.

Glazing

Significant improvement in stringency is proposed whilst still being comparable to ASHRAE 90.1. Satisfactory windows that perform with a minimum function are proposed of at least 5% DF in a perimeter zone. It is found that U-Value and SHGC x WWR is enough to specify the cheapest complying window rather than the current complicated method in NCC Section J2.

Fans and pumps

A total system pressure drop is proposed for fans and pump efficiency and maximum straight pipe pressure loss is proposed for pumps.

Tighten insulation on pipes, heated vessels and heat exchangers is proposed.

Mechanical and hydraulic equipment

Chillers and PAC units are proposed to have a slightly higher COP.

Hot water heaters (condensing boilers) are proposed to have a higher efficiency.

Cooling towers fan power are proposed to be more stringent in terms of induced and forced draft.

Economy cycle is proposed with reduced stringency with significant increased stringency in outside air treatment.

Artificial lighting

Stringencies reset based on 2017 LED technology and maximum power density requirements are proposed to be dropped significantly in the new requirements.

Perimeter lighting, foyers and circulation spaces are proposed with further DTS control requirements.

Lifts

Lift provisions are proposed as per ASHRAE 90.1 for lighting, lfit car ventilation.