Insulat ion
The impact of under slab insulation on building performanceHOW A ‘ONE-FITS-ALL’ INSULATION SOLUTION CAN HELP ACHIEVE A 6 STAR ENERGY EFFICIENCY RATING IRRESPECTIVE OF NATHERS CLIMATE ZONE OR ORIENTATION.
Issue 1 May 2017
A4/12 Carb5-1
Compacted Aggregate / Sand BlindingKingspan Kooltherm
® K3 Floorboard
Damp Proof Membrane
Subsoil
Masonry Cavity Wall
Kingspan Kooltherm®
K8 Cavity Board
Concrete Slab
Separation Layer (e.g. polythene sheet)
Low Energy – Low Carbon Buildings
www.kingspan.com/au/6star
2
Introduction
“Would the addition of Kingspan Kooltherm® K3 Floorboard under a CSOG construction provide a significant increase in overall thermal performance when compared to uninsulated slabs?”
In Victoria all new dwellings, renovations, alterations and additions need to comply with the 6 Star Standard in the National Construction Code. The 6 Star Standard applies to the thermal performance of a dwelling, renovation or addition. A 6 Star energy efficiency rating applies to a dwelling’s building envelope – its roof, walls, windows and floor. Design options that go beyond minimum regulatory requirements pay in the long run and improve the value of a dwelling.
Meeting 6 Star compliance is not difficult. It’s about good design, planning and taking advantage of benefits, such as increased comfort, savings on energy bills and making a dwelling more resilient to changes in climate. A dwelling’s orientation can add up to 1 Star to the rating.
6 Star dwellings are projected to use 24% less energy through heating and cooling, compared to 5 Star dwellings, which means a potential saving on today’s energy bill, as well as considerably more on future bills, as energy costs continue to grow. 1
Kingspan Kooltherm® K3 Floorboard under slab insulation achieves a 6 Star rating across different climate zones and most orientations, without the need to change any other building specifications, such as glazing, shading or additional insulation in walls and ceilings.
To test this, a study by Graham Energy (graham.energy) was conducted to show the impact of Kingspan Kooltherm® K3 Floorboard under slab insulation on the Star rating of a typical residential dwelling in Victoria, when compared to no insulation (concrete slab-on-ground [CSOG]) and waffle pod construction. Would the addition of Kingspan Kooltherm® K3 Floorboard under a CSOG construction provide a significant increase in overall thermal performance when compared to uninsulated slabs?
1 Victorian Building Authority – Six Star Standard (vba.vic.gov.au/consumers/6-star-standard)
Background
3
Study Methodology
A baseline FirstRate5 assessment was established for a dwelling with typical building fabric insulation levels and glazing specifications. The concrete slab floor construction was then assessed under the following three conditions:
1. without insulation2. with Kingspan Koolherm® K3 Floorboard3. with waffle pod construction
This dwelling was assessed in three different NatHERS climate zones in Victoria with differing orientation. The locations selected (Brunswick, Truganina and Cranbourne East) were all in high growth areas.
The waffle pod construction selected as a comparison was 375-85, or 375 mm high waffle pod with 85 mm structural slab. This option represents a ‘best case’ scenario with a maximum R0.9 currently permitted in all NatHERS software.
To allow for a better representation of the benefit of under slab insulation, the scope was broadened to include all cardinal and ordinal directions, as providing only the four primary cardinal directions (north, south, east, west) did not represent a complete picture based on the selected design.
The DwellingThe dwelling selected was a single level dwelling designed by Henley. It is part of the Carmelle series with the Lux Q2 options selected – 4 bedrooms; 2 bathrooms; powder room; double garage; 4 living areas, including a theatre room; kids retreat; butler’s pantry and alfresco area.
SQU
AR
ES
LOT W
IDTH 14M
+28.37
ca
rme
llelu
x Q2
42.5
24
LIVIN
G A
RE
AS
Living4700 x 4990
Dining
3430 x 4320
Theatre3830 x 5300
Kids' R
etreat3150 x 3000
BE
DR
OO
MS
Master S
uite3290 x 4850
Bed 2
3330 x 3000
Bed 3
3150 x 3200
Bed 4
3000 x 3300
OU
TDO
OR
RO
OM
Alfresco
2760 x 4690
TOTA
L AR
EA
S
Ground Floor
209.2 m2
Garage
36.5 m2
Porch
4.1 m2
Alfresco
13.5 m2
Total28.37 sq
263.6 m2
Exterior Length
25,360
Exterior W
idth12,800
MIM
IMU
M LO
T WID
TH
Metric
14 m
Imperial
46 ft
Dim
ensions and floorplan shown are based on B
roadway facade.
Copyright H
enley Arch Pty Ltd. All rights reserved. All plans are copyright, no part may be used, reproduced or copied by any m
eans or in any form w
ithoutthe prior perm
ission of Henley Arch Pty Ltd.
All measurem
ents are in millim
eters unless otherwise stated. M
arketing plans are representative only. Please refer to master draw
ings for accurate featuresand dim
ensions. Lot widths are based on standard facade and m
ay vary depending on facade chosen. Please speak to your Sales Consultant for a full list of
standard inclusions. Due to estate requirem
ents and council guidelines some lot w
idth requirements w
ill change and need to be used as a guide only.
4
Study Methodology
The specifications below are independent of those adopted by Henley and were used for testing purposes only.
Specification A, which provides the lowest thermal performance, has been tested under all three conditions
(without insulation, with Kingspan Kooltherm® K3 Floorboard and with waffle pod construction), whereas specifications B and C, which provide a gradually increasing thermal performance, have only been tested for CSOG without insulation and CSOG with waffle pod construction.
Dwelling Specification A House Garage
Insulation External Wall R2.0 wall batt None
Internal Wall None R1.5 wall batt
Ceiling R3.5 ceiling batt None
Building Sealing Roof Sarking Not sarked Not sarked
Dwelling Specification B House Garage
Insulation External Wall R2.5 wall batt None
Internal Wall None R1.5 wall batt
Ceiling R4.0 ceiling batt None
Building Sealing Roof Sarking Sarked Sarked
Dwelling Specification C House Garage
Insulation External Wall R2.7 wall batt None
Internal Wall None R1.5 wall batt
Ceiling R5.0 ceiling batt None
Building Sealing Roof Sarking Sarked Sarked
5
Climate Zones
French Island
Geelong
Werribee
Melbourne
Port Phillip Bay
BRUNSWICK
Melbourne Monthly Climate Data
Tem
pera
ture
(°C
), M
oist
ure
(g/k
g), W
ind
(m/s
ec) o
n si
te
Sola
r kW
h pe
r mon
th
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
40.0
35.0
30.0
25.0
20.0
15.0
10.0
5.0
0.0
300
250
200
150
100
50
0
Global Solar
Av. Max.
Av. Min.
Wind
Moisture
NatHERS Climate Zone 21
Suburb Brunswick
Postcode 3056
Elevation 45.76 metres above sea level
* Sourced from the online NatHERS Interactive Climate map.
6
Study Methodology
French Island
Geelong
Werribee
MelbourneTRUGANINA
Port Phillip Bay
Tullamarine Airport Monthly Climate Data
Tem
pera
ture
(°C
), M
oist
ure
(g/k
g), W
ind
(m/s
ec) o
n si
te
Sola
r kW
h pe
r mon
th Global Solar
Av. Max.
Av. Min.
Wind
Moisture
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
40.0
35.0
30.0
25.0
20.0
15.0
10.0
5.0
0.0
300
250
200
150
100
50
0
NatHERS Climate Zone 60
Suburb Truganina
Postcode 3029
Elevation 21.41 metres above sea level
* Sourced from the online NatHERS Interactive Climate map.
7
French Island
Geelong
Werribee
Melbourne
CRANBOURNE EASTPort Phillip Bay
Moorabbin Airport Monthly Climate Data
Tem
pera
ture
(°C
), M
oist
ure
(g/k
g), W
ind
(m/s
ec) o
n si
te
Global Solar
Av. Max.
Av. Min.
Wind
Moisture
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
40.0
35.0
30.0
25.0
20.0
15.0
10.0
5.0
0.0
300
250
200
150
100
50
0
Sola
r kW
h pe
r mon
th
NatHERS Climate Zone 62
Suburb Cranbourne East
Postcode 3977
Elevation 48.74 metres above sea level
* Sourced from the online NatHERS Interactive Climate map.
8
Findings
Star Rating Summary
Orientation CSOG (A)
CSOG (B)
CSOG (C)
Waffle Pod (A)
Waffle Pod (B)
Waffle Pod (C)
K3 25
K3 30
K3 40
K3 50
NatHERS CZ 21 S 5.3 5.4 5.6 5.7 5.9 5.9 5.8 5.9 5.9 6.0
Brunswick SW 5.2 5.4 5.5 5.7 5.9 5.9 5.8 5.9 5.9 5.9
W 5.3 5.4 5.6 5.8 5.9 6.0 5.9 5.9 5.9 6.0
NW 5.4 5.6 5.7 5.9 6.0 6.1 5.9 6.0 6.1 6.1
N 5.5 5.7 5.8 6.0 6.2 6.2 6.1 6.2 6.2 6.3
NE 5.4 5.5 5.7 5.8 5.9 6.1 5.9 5.9 6.0 6.1
E 5.3 5.4 5.6 5.8 5.9 5.9 5.9 5.9 5.9 6.0
SE 5.2 5.3 5.4 5.7 5.8 5.9 5.8 5.8 5.9 5.9
NatHERS CZ 60 S 5.2 5.3 5.4 5.7 5.9 5.9 5.8 5.9 5.9 6.0
Truganina SW 5.1 5.3 5.4 5.7 5.8 5.9 5.8 5.8 5.9 5.9
W 5.2 5.4 5.4 5.7 5.9 5.9 5.9 5.9 5.9 6.0
NW 5.3 5.4 5.6 5.9 6.1 6.1 5.9 6.0 6.1 6.2
N 5.4 5.6 5.8 6.1 6.2 6.3 6.2 6.2 6.3 6.3
NE 5.3 5.4 5.6 5.8 5.9 6.1 5.9 5.9 6.1 6.1
E 5.2 5.3 5.4 5.7 5.9 5.9 5.9 5.9 5.9 6.1
SE 5.1 5.3 5.4 5.6 5.8 5.9 5.8 5.8 5.9 5.9
NatHERS CZ 62 S 5.1 5.3 5.4 5.7 5.9 5.9 5.8 5.9 5.9 6.1
Cranbourne East SW 5.1 5.3 5.4 5.7 5.9 5.9 5.8 5.9 5.9 6.0
W 5.2 5.3 5.4 5.8 5.9 6.0 5.9 5.9 6.0 6.1
NW 5.3 5.4 5.6 5.9 6.0 6.1 5.9 6.0 6.1 6.2
N 5.4 5.6 5.7 5.9 6.2 6.3 6.1 6.2 6.3 6.3
NE 5.3 5.4 5.6 5.9 6.0 6.1 5.9 6.0 6.1 6.2
E 5.2 5.4 5.4 5.8 5.9 6.0 5.9 5.9 6.1 6.1
SE 5.1 5.3 5.4 5.7 5.9 5.9 5.8 5.9 5.9 6.0
9
WSWS NEN SEENW
CSOG (A) CSOG (B) CSOG (C) Waffle Pod (A) Waffle Pod (B) Waffle Pod (C) K3 25 K3 30 K3 40 K3 50
6.36.26.16.05.95.85.75.65.55.45.35.25.15.0
Orientation
Star
s
NatHERS CZ 21 (Brunswick)
WSWS NEN SEENW
CSOG (A) CSOG (B) CSOG (C) Waffle Pod (A) Waffle Pod (B) Waffle Pod (C) K3 25 K3 30 K3 40 K3 50
6.36.26.16.05.95.85.75.65.55.45.35.25.15.0
Orientation
Star
s
NatHERS CZ 60 (Truganina)
WSWS NEN SEENW
CSOG (A) CSOG (B) CSOG (C) Waffle Pod (A) Waffle Pod (B) Waffle Pod (C) K3 25 K3 30 K3 40 K3 50
6.36.26.16.05.95.85.75.65.55.45.35.25.15.0
Orientation
Star
s
NatHERS CZ 62 (Cranbourne East)
10
Findings
The dwelling with no under slab insulation, across all three climate zones with varying orientations, ranged between 5.1 to 5.5 Stars. This is below the minimum regulatory requirement of 6.0 Stars in Victoria and additional improvements to building specifications would need to be considered to achieve compliance.
Adopting the maximum permitted waffle pod construction with R0.9 achieved minimum regulatory compliance in two of the three climate zones, however this was only when the orientation of the dwelling was optimal for the design – due north.
The introduction of Kingspan Kooltherm® K3 Floorboard 25 mm (R1.2) ensured the dwelling achieved minimum regulatory compliance in all three climate zones but, similar to the waffle pod construction with R0.9, only when the orientation of the dwelling was ideal.
Increasing the floor insulation to Kingspan Kooltherm® K3 Floorboard 30 mm (R1.4) provided greater flexibility in achieving minimum regulatory compliance across all three climate zones, especially when the orientation of the dwelling was slightly less than optimal. For waffle pod construction to achieve similar results to that of Kingspan Kooltherm® K3 Floorboard 30 mm (R1.4), overall specifications of the dwelling would need to be improved.
Stepping up the floor insulation specification again, to Kingspan Kooltherm® K3 Floorboard 40 mm (R1.9), provided even greater scope to achieve minimum regulatory compliance of 6 Stars. This included achieving 6 Stars, or greater, for all orientations from W to E in one of the climate zones – climate zone 62 Cranbourne East.
Kingspan Kooltherm® K3 Floorboard 50 mm (R2.5) achieves minimum regulatory compliance across almost all orientations in the three NatHERS climate zones – 20 of 24 orientations across the three zones rated 6.0 Stars or above, with just 4 ratings at 5.9 Stars.
Even with significantly increased wall and ceiling insulation, as well as building sealing levels (Specifications B & C), neither the CSOG without insulation, nor the waffle pod construction, could improve up to the level of the Kingspan Kooltherm® K3 Floorboard insulation option.
ConclusionThese results show the addition of Kingspan Kooltherm® K3 Floorboard under a CSOG construction provides a significant increase in overall thermal performance when compared to uninsulated flooring, even when compared to specifications B and C with substantially increased wall and ceiling insulation and building sealing levels.
When compared to waffle pod construction, with the values currently permitted in all NatHERS software, Kingspan Kooltherm® K3 Floorboard either matches or improves overall results, irrespective of the specification level of walls and ceiling insulation.
Specifying Kingspan Kooltherm® K3 Floorboard potentially increases a dwelling’s rating by up to 1 Star and significantly contributes to achieving a minimum 6 Star rating for regulatory compliance without the need to change building design or boosting walls and ceiling insulation levels.
There is no doubt the impact that Kingspan Kooltherm® K3 Floorboard under slab insulation has on building performance. As a ‘one-fits-all’ insulation solution, Kooltherm® K3 can help achieve a 6 Star energy efficiency rating irrespective of climate zone or orientation.
References • Kooltherm® K3 Floorboard Study. Prepared for Kingspan Insulation
Pty Ltd by Graham Energy (graham.energy) October 2016• Kooltherm® K3 (kingspan.com/au/K3) • Victorian Building Authority – Six Star Standard
(vba.vic.gov.au/consumers/6-star-standard)
“Even with boosted wall and ceiling levels neither of the alternative constructions could improve up to the level of the Kingspan Kooltherm® K3 Floorboard option.”
11
About Kingspan Kooltherm® K3 Floorboard
Kingspan Kooltherm® K3 Floorboard is a super high performance, rigid, thermoset phenolic insulation with a fibre free, closed cell insulation core. This core is sandwiched between two layers of tissue based facing. The facings are autohesively bonded to the insulation core during manufacture.
Kingspan Kooltherm® K3 Floorboard is manufactured without the use of CFCs / HCFCs and has zero Ozone Depleting Potential (ODP) and low Global Warming Potential (GWP).
Product R-values
Key Benefits:
• Helps increase a project’s rating by up to 1 Star
• ‘One-fits-all’ insulation solution (saves on design development costs)
• Resistant to the passage of water vapour
• Easy to handle and install
• Compliant with AS/NZS 4859.1
Product Data
Thermal Conductivity (λ-value)
0.020 W/m K (Insulant thickness ≥ 45 mm)
0.021 W/m K (Insulant thickness 25 - 44 mm)
Product Dimensions 2400 mm x 1200 mm (2.88 m2)
Product Thickness 25, 30, 40, 50 mm
Product Thickness Product R-Value
25 mm R1.2
30 mm R1.4
40 mm R1.9
50 mm R2.5
Masonry cavity wall
Kingspan Kooltherm®
K8 Cavity Board
Kingspan Kooltherm®
K3 FloorboardDamp proof membrane
Compacted aggregate/sand blinding
Concrete slab
Separation layer (e.g. polythene sheet)
Insulation for solid concrete ground based floors
Kooltherm® K3 Floorboard is a super high performance under slab insulation available in various thicknesses to help achieve 6 Star thermal performance.
Kingspan Insulation Pty LtdTel: 1300 247 235
Email: [email protected]
® Kingspan, Kooltherm and the Lion Device are Registered Trademarks of the Kingspan Group plc in Australia and other countries. All rights reserved. © Kingspan Insulation Pty Ltd
Kingspan Insulation Pty Ltd reserves the right to amend product specifications without prior notice. The information, technical details and fixing instructions etc. included in this literature are given in good faith and apply to uses described. Recommendations for use should be verified as to the suitability and compliance with actual requirements, specifications and any applicable laws and regulations. For other applications or conditions of
use, Kingspan Insulation offers a Technical Advisory Service the advice of which should be sought for uses of Kingspan Insulation products that are not specifically described herein. Please check that your copy of the literature is current by contacting us or visiting www.kingspaninsulation.com.au
Contact Details
General EnquiriesTel: 1300 247 235
Email: [email protected]
www.kingspaninsulation.com.au