# 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 Better Building

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.