J4D7 Floors

What is J4D7 Floors?

J4D7 Floors outlines the thermal insulation requirements for floors to improve energy efficiency. Key provisions include:

Total R-Value:

Floors must achieve the Total R-Value specified in Table J4D7, which varies based on the building's classification and climate zone.

Slab-on-ground Exemptions:

A slab-on-ground floor without an in-slab heating or cooling system is generally considered to achieve an R-Value of R2.0, except in two cases:

• Climate zone 8.

• Class 3, Class 9a ward areas, or Class 9b buildings in climate zone 7 with a floor area to floor perimeter ratio of less than or equal to 2.

Perimeter Insulation:

• Floors must be insulated along their vertical edge with insulation having an R-Value of at least 1.0 in the following cases:

  • Concrete slab-on-ground floors in climate zone 8.

  • Floors with in-slab or in-screed heating or cooling systems, except when used solely in bathrooms or amenity areas.

Insulation Requirements:

• The insulation for concrete slab-on-ground floors must be water resistant.

• It must be continuous from the adjacent finished ground level to a depth of at least 300 mm or for the full depth of the slab's vertical edge.

Table J4D7 Floors – Minimum Total R-Value

Location	Climate zone 1 — upwards heat flow	Climate zones 2 and 3 — upwards and downwards heat flow	Climate zones 4, 5, 6 and 7 — downwards heat flow	Climate zone 8 — downwards heat flow
A floor without an in-slab heating or cooling system	2.0	2.0	2.0	3.5
A floor with an in-slab heating or cooling system	3.25	3.25	3.25	4.75

For the purpose of calculating the Total R-Value of a floor, the sub-floor and soil R-Value must be calculated in accordance with Specification 39 or Section 3.5 of CIBSE Guide A.

J4D7 Floors on Speckel

Speckel automatically checks the provisions of J4D7 Floors against your design, while providing AS/NZS 4859.2 and CIBSE Guide A calculations within our Floor applications.