case study – ncc 2019 proposed upgrade · the analysis finds that, for the case of the proposed...

Dept of Environment & Energy Case Studies – NCC2019 Boarding House

Team Catalyst ROSELANDS BOARDING HOUSE UPGRADE

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ISSUED 13AUG2018

Team Catalyst ACN 114 572 084 "Driving Sustainability through Teamwork" e: [email protected] m: 0417 405 478

Department of the Environment & Energy

Case Study – NCC 2019 Proposed Upgrade

Boarding House

mailto:[email protected]



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CONTENTS

1 EXECUTIVE SUMMARY ....................................................................................................... 3

1.1 ENERGY/GHG EMISSIONS ................................................................................. 5

1.2 COST IMPLICATIONS .......................................................................................... 5

1.2.1 WINDOW SYSTEMS ............................................................................................................. 5

1.2.2 LED LIGHTING ...................................................................................................................... 5

1.3 CONCLUSIONS .................................................................................................... 6

1.4 ABOUT THE BUILDING ........................................................................................ 7

1.5 DISCLAIMER ........................................................................................................ 7

2 BACKGROUND ..................................................................................................................... 8

3 CASE STUDY DESCRIPTION ............................................................................................... 9

4 METHOD ..............................................................................................................................11

4.1 GEOMETRY .........................................................................................................11

4.2 CONSTRUCTION SYSTEM .................................................................................13

4.2.1 (J1.3) ROOF..........................................................................................................................13

4.2.2 (J1.6) FLOOR........................................................................................................................14

4.2.3 (J1.5) NCC 2016 WALL CONSTRUCTION ...........................................................................15

4.2.4 (J2) NCC 2016 GLAZING CALCULATOR ............................................................................15

4.2.5 (J 1.5) NCC 2019 COMBINED WALL GLAZING CONSTRUCTIONS ..................................17

4.2.6 HYPOTHETICAL PROPOSED BUILDING WALL-GLAZING SELECTION ...........................20

4.3 DTS HVAC SYSTEM ...........................................................................................21

4.4 (J1.6) LIGHTING ..................................................................................................24

4.5 SIMULATION PARAMETERS ..............................................................................24

4.5.1 MODELLING PARAMETERS ...............................................................................................24

4.5.2 MODELLING PROFILES ......................................................................................................25

5 RESULTS AND CONCLUSIONS ..........................................................................................27

5.1 ENERGY/GHG EMISSIONS ................................................................................28

5.2 COST IMPLICATIONS .........................................................................................29

5.2.1 WINDOW SYSTEMS ............................................................................................................29

5.2.2 LED LIGHTING .....................................................................................................................29

6 CONCLUSIONS ....................................................................................................................29



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1 EXECUTIVE SUMMARY The Boarding House project at Roselands, NSW is still in design development stage, and consists of nine sole occupancy units and a communal lounge. Out of the nine units, six are proposed to be two storey structures, with a mezzanine bedroom. The three remaining units and communal lounge room are proposed to be single storey structures. The project is a class 3 building under the NCC, located at Roselands, inner western Sydney which falls in NCC Climate Zone 5.

Run Plan NCC 2016 Reference Building

GFA 386m2

NCC 2019 Reference Building

GFA 386m2

NCC 2016 ENV +NCC 2019 LTG + SIM

GFA 386m2

Proposed Hypothetical Building

GFA 386m2

Run Description

Reference building with NCC 2016 DTS compliant Envelope (J1 and J2), HVAC J5, Lighting J6 and NCC 2016 JV3 Sim Parameters

Reference building with NCC 2019 DTS compliant Envelope J1 , HVAC J5, Lighting J6 and NCC 2019 JVc SIM Parameters

Interim Run with NCC 2016 DTS Envelope, and NCC 2019 compliant HVAC J5, Lighting J6 and NCC 2019 JVc SIM Parameters

Improved Building with a hypothetical proposed Envelope and NCC 2019 compliant HVAC J5, Lighting J6 and NCC 2019 JVc SIM parameters

EnergyEnd Uses kWh kWh/m2 kWh kWh/m2 kWh kWh/m2 kWh kWh/m2

Heating 2,150 5.6 3,856 10.0 4,940 12.8 3,846 10.0

Cooling 642 1.7 1,941 5.0 1,755 4.5 2,102 5.4Interior Lighting 15,248 39.5 11,105 28.8 11,105 28.8 11,105 28.8Interior Equipment 16,923 43.8 15,325 39.7 15,325 39.7 15,325 39.7Fans 2,056 5.3 3,353 8.7 3,499 9.1 3,004 7.8

Total End Uses 37,019 95.9 35,579 92.2 36,623 94.9 35,381 91.7

Total HVAC 4,848 12.6 9,149 23.7 10,193 26.4 8,951 23.2

Greenhouse Gas Emissions kgCO2-e /GJ 35,316 91.5 33,942 87.9 34,938 90.5 33,753 87.4% over 2019 REF Allowance 4% 0% 3% -1%



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The Verification Method JV3 was applied to the project. Building models that “just complied” with the current 2016 DTS requirement and the proposed 2019 upgrade of NCC Section-J were developed and analysed for the building design. In small and medium sized building projects, similar to the Roselands project, the building industry tries to optimise the building envelope for cost. Therefore, compliance with Section-J is usually tested using a hybrid approach. Energy simulation models are used to test building envelope performance, using DTS compliant services (HVAC and lighting systems) as per clause JV3 (a)(i)(B). It is noted that this case study uses DTS compliant HVAC systems for all runs; therefore the impact of changes to HVAC system design and specification has not been investigated.

The results above are for the three building simulation models developed for the Roselands boarding house project described earlier (and reproduced below).

NCC 2016 Reference Building: building envelope (J1 and J2), HVAC (J5) and Lighting (J6) are compliant with NCC2016 DTS requirements. Simulation parameters used are from NCC2016. This run sets the reference energy budget for NCC2016

NCC 2019 Reference Building: building envelope (J1), HVAC (J5), Lighting (J6) are compliant with NCC2019 DTS requirements. Simulation parameters are from the proposed NCC2019 draft. This run sets the reference energy budget for the proposed NCC2019

Proposed Hypothetical Building: uses an improved hypothetical building envelope, while the HVAC, Lighting and simulation parameters are as per the proposed NCC2019 draft. This run is an indication of what may need to be done to an existing building to comply with the proposed NCC2019

A fourth interim modelling run (in blue) reviews the performance of the building when fitted with the NCC2016 building envelope, but modelled with all other systems and modelling requirements from the proposed NCC2019. A comparison of the green and blue results isolates the performance of just the building envelope stringency requirements, between the existing NCC2016 provisions and the proposed NCC2019 provisions.



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1.1 ENERGY/GHG EMISSIONS

The results indicate that, for the case of the proposed Roselands boarding house project:

1. There is a predicted 4% reduction in GHG emissions between the compliance requirements of NCC 2019 Reference Building and that of the NCC 2016 Reference Building. Buildings similar to the proposed Roselands boarding house project in climate zone 5 would be impacted in this manner, which includes Sydney, Perth and Adelaide, all of which are heavily populated areas in Australia

2. Comparing the predicted results from the interim runs (the green and blue columns) indicate that the proposed NCC2019 building envelope stringencies are higher that of NCC2016. For the proposed Roselands boarding house, the NCC2016 building envelope is predicted to release 3% more GHG emissions than the NCC2019 Reference Building.

3. The window/façade performance was made more stringent (as described in section 4.2.6) to reduce GHG emissions from the Proposed Hypothetical Building model to pass the NCC2019 Reference Building allowance. These changes to glazing, wall and roof/ceiling are predicted to reduce emissions to 1% below the NCC2019 Reference Building levels

4. This result should not be generalised, and should be tested for other NCC Class of buildings in other climate zones. However, the results seem to indicate that smaller, Class 3, in climate one 5, have a small increase to building envelope stringency requirement under the proposed NCC2019 provisions.

1.2 COST IMPLICATIONS

Capital cost implications of the proposed NCC 2019 initiatives for this case study would mainly be in the areas of building envelope and LED lighting.

1.2.1 WINDOW SYSTEMS

The glazing selection for the NCC2019 Reference Building model indicate that the minimum window specifications for the proposed Roselands boarding house project to comply with the proposed NCC2019 provisions require the performance of some of the windows to be increased to high performance double glazed systems (U2.5 and SHGC 0.5), when compared to the existing NCC2016 provisions. The additional cost on this project is estimated to be in the range of $50,000 - $75,000

1.2.2 LED LIGHTING

In the case of LED vs CFL lights, LEDs are marginally more expensive at this time, but prices are reducing steadily. It is conceivable that by the time the proposed NCC2019 legislation is implemented, LEDs will be the technology of choice. At this point, the cost differential for a standard 90mm LED downlight fitting with dimmable driver is about 2 – 4 times the cost of an CFL lamp which can fit into a standard (incandescent) lamp mount. Payback has been estimated at 3 – 5 years. Labor cost for installations of either type of downlight are comparable. LED fittings that are “IC” rated are already available in the marketplace. These fittings can have insulation installed directly over them, without the need for cutting holes in the insulation on the ceiling. This one



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characteristic alone would reduce heating energy consumption, by reducing heat loss from the ceiling in winter. Such fittings would be very beneficial for projects like the proposed Roselands boarding where the energy consumption for heating can be twice as high as for cooling (night operating buildings in moderate climates).

1.3 CONCLUSIONS

The analysis finds that, for the case of the proposed 2019 NCC JV3 compliance requirements (NCC 2019 Reference Building), there is a small but significant reduction in the predicted annual GHG emissions when compared to the 2016 JV3 compliance requirements. There is a predicted 4% reduction in GHG emissions between the NCC2019 Reference Building and proposed NCC2016 Reference Building models. There is also a predicted 3% reduction between a the NCC2019 Reference Building model and the “interim” model, once fitted with NCC2016 building envelope, but with all NCC2019 modelling parameters and modelling profiles. This is a clear indication that building envelope requirements in the NCC2019 are slightly more stringent.

Finally, it is reiterated that the proposed Hypothetical Building model provides one possible compliance solution, in which the window system performance specifications and the ceiling/roof insulation levels were made more stringent to show compliance with the proposed NCC2019 provisions.



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1.4 ABOUT THE BUILDING

Table 1: Summary of building details

Building name (if applicable) and address

Roselands Boarding House Owner Developer Builder TBC Architect Steven Kennedy and Associates Services consultants TBC

Leasing agent (if applicable) N/A

Client development manager N/A

End users (if known) Tenants

Building classification Class 3 (boarding house) Deemed building hours of operation. Nighttime operation

Size GLA 386 m2

Number of stories 2 (mezzanine for 6 out 9 units) Completion date in Design Development Construction cost Not available as yet

Proposed or achieved environmental certifications and status N/A

1.5 DISCLAIMER

This research study uses the building geometry description of the Roselands Boarding House, and theoretically tests a combination of building fabric and other systems that resulted in one of a myriad of compliant solutions with reference to NCC Section-J. The particular compliance combination arrived at for this study may have no similarities to the as-built building.



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2 BACKGROUND The Department of Environment and Energy has commissioned a series of case studies relating to the changes proposed for upgrade of Section-J for 2019. The objectives for the case studies are to … “illustrate the impact of the proposed changes to the NCC, which will then be used as some communication materials for the industry. The case studies need to demonstrate compliance with the current (2016) provisions of Section J, and chronicle any variations in the design needed to meet the 2019 proposed provisions. The intent is to illustrate the practicability of the proposed changes and the ease of compliance; with a secondary intent to test and uncover any deficiencies in the Code, if any”.

Team Catalyst have been commissioned to develop three case studies:

• A large retail shopping centre addition, Class 6, Climate Zone 5

• A nine-unit boarding house complex with communal room, Class 3, Climate Zone 5, and

• A community centre that is the social hub in a retirement living village (RLV), Class 9c, Climate Zone 6

This report details the outcomes of analysing the Roselands Boarding house with the Verification Method JV3 compliance requirements for the existing 2016 Section-J, and then with the proposed changes for 2019.



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3 CASE STUDY DESCRIPTION The Boarding House proposed at Roselands, NSW consists of nine sole occupancy units and a communal lounge. Out of the nine units, six units are proposed to be two storey structures, with a mezzanine bedroom. The three other units and communal lounge room are proposed to be single storey structures. The project has been modelled as a night time use building, extending into morning operation. It is classified as a Class 3 building under the NCC, located at Roselands, inner western Sydney which falls in NCC Climate Zone 5.

The JV3 Verification Method was applied to the project. Building models that “just complied” with the current 2016 DTS requirement and the proposed 2019 upgrade of NCC Section-J were developed and analysed for the building design. In small and medium sized building projects, similar to the Roselands project, the building industry tries to optimise the building envelope for cost. Therefore, compliance with Section-J is usually tested using a hybrid approach. Energy simulation models are used to test building envelope performance, using DTS compliant services (HVAC and lighting systems) as per clause JV3 (a)(i)(B).

Three building simulation models of the Willowdale Community Centre have been developed for this case study. These are described below.




The following sections develop calculations that refer to the three models referred to above, ie., NCC2016 Reference Building, NCC2019 Reference Building and the Proposed Hypothetical Building, and these values are used to populate inputs to the models described above.



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Figure 1: Roselands Boarding House, Architect representation (project at Design Development stage)



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4 METHOD 4.1 GEOMETRY

A representative building model was developed in the DesignBuilder/EnergyPlus software suite. For both the NCC2016 and draft NCC2019 runs, the same geometry, including window dimensions, shading, wall thickness, zoning, and operation schedules were maintained.

Figure 2: Ground Floor Layout with appropriate zoning as modelled for both the NCC 2016 Reference Building and draft NCC 2019 Reference Building modelling runs.



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Figure 3: First Floor Layout with appropriate zoning as modelled for both the NCC 2016 Reference Building and draft NCC 2019 Reference Building modelling runs.

Figure 4: 3d view of the Boarding House including shading details from the architectural drawings



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4.2 CONSTRUCTION SYSTEM

A detailed description of the type of construction for each building element is presented in this section. The performance criteria specified in Section J1 and J2 of NCC 2016 and Section J1 of Draft NCC 2019 are tabulated. At the end of the section, a construction system is selected for the Proposed Hypothetical building.

4.2.1 (J1.3) ROOF

The building design had areas which were covered with a skillion roof, and some areas covered by a pitched roof and ceiling. For both the NCC 2016 and NCC 2019 models, thermal bridging has been accounted for in the calculations.

Figure 5: Typical flat roof construction used in both the 2016 and 2019 models

Figure 6: Typical Pitched roof construction used in both the 2016 and 2019 models



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Table 2: NCC 2019 and NCC 2016 Reference Building Roof and Ceiling construction

4.2.2 (J1.6) FLOOR

A 250mm thick concrete slab on ground construction was modelled for both the NCC 2016 and NCC 2019 reference building models as represented in the figure below.

Figure 7: Slab on ground construction as modelled

Table 3: NCC 2016 and 2019 Reference Building Floor Construction

Slab-on-ground construction for locations in climate zone 5 are calculated to not require any additional insulation for the building being analysed under the proposed provisions for NCC2019.

Calculation TypeRequired Total R

Value m2-K/WProposed Total R

Value m2-K/W

Bridged Roof and ceiling construction for NCC 2016 Reference Building

R 4.2 @ 0.7 Sol Abs

Bridged Roof and ceiling construction for NCC 2019 Reference Building

R 3.7 @ 0.4 Sol Abs

Bridged Roof and Ceiling construction for Proposed Hypothetical Building R 5.0 @ 0.4 Sol Abs

Calculation Type Ground Slab Thickness, mm

NCC 2016 Slab on Ground 250

NCC 2019 Slab on Ground 250

Proposed Hypothetical Building 250 No additional insulation required for compliance

Required Total R Value m2-K/W

No additional insulation required.

As per section 3.5 of CIBSE Guide A, the calculated Uf = 0.24 W/m2-K. This complies with Table J1.6 of Draft NCC 2019, for a floor without an inslab heating or cooling systemNo additional insulation required



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4.2.3 (J1.5) NCC 2016 WALL CONSTRUCTION

Timber framed Brick Veneer wall construction was used for both reference building models. The typical construction details can be seen in the image below. The NCC 2016 Reference building was modelled without accounting for thermal bridging.

Figure 8: Typical Brick Veneer wall construction

Table 4: NCC 2016 wall total R-values are listed below

4.2.4 (J2) NCC 2016 GLAZING CALCULATOR

Whole window solar thermal performance selections for NCC 2016 are shown in the Glazing Calculator tables below (Table 4 and Table 5) for Ground and First floor. Care has been taken to specify window performance combinations that are readily achievable in practise, and a minimum number of differently performing windows are selected. The combination of windows is designed to result in a “just pass” set of selections. Most of the selected combinations can be achieved with single glazed windows, with W and E facing windows requiring double glazed configurations. Selected whole window U-values range between 2.5 (double) and 5.8 W/m2-K (single).

Wall TypeRequired Total System R Value m2-K/W

North, East and West External Envelope Walls R2.8South External Envelope Wall R2.3

Internal Envelope Walls ≤ R1.8



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Table 5: Glazing calculator showing DTS Glazing requirements for NCC 2016 reference building – Ground Floor



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Table 6: Glazing calculator showing DTS Glazing requirements for NCC 2016 reference building – First Floor

4.2.5 (J 1.5) NCC 2019 COMBINED WALL GLAZING CONSTRUCTIONS

Possibly the most significant change in the proposed NCC2019 compliance methods are the manner in which walls and windows are to be analysed. In the current NCC2016, these elements are treated separately, however in the proposed NCC2019 methods, the solar-thermal performance of each façade aspect is tested in a combined manner. There are two alternative calculation methods documented in the proposed NCC2019, and Method 1 has been used for this case study.

The thermal performance of the wall and window system is to be evaluated using a “Total System U-value” using an area-based average. Table 7 lists the total wall system U-values (after accounting for thermal bridging) for wall constructions that have been derived for the NCC2019 Reference Building case. The resultant limiting R-values used in the Reference Case model are listed in the third column from the right in table 7. On the ground floor, the R-value for each façade was calculated independently. On the first floor, a single, uniform R-value was calculated for all walls with WWR > 20% using an area-based average approach. Both approaches are allowed. The



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total R-value for walls with window-to-wall ratios less than 20% are fixed at R1.4 (South walls on ground floor, and North walls on first floor for this case study).

Figure 9 : Typical Brick Veneer wall construction

Table 7: NCC 2019 Reference Building Wall - Total System R Values including Thermal Bridging

Note: The internal and external film coefficients were accounted for in the total R Value calculations.

Calculation of the solar transmission performance for each façade aspect is more complex. The proposed NCC2019 code limits the “Façade Solar Admittance” for each façade aspect, which considers the dimension of each individual window, a Shading Multiplier, the SHGC of each window and the total area of the wall-glazing construction. The maximum allowable SHGC for windows (glazing) on each façade, by floor and orientation, has been computed (Table 8) after selecting a practical U-value for each façade, summarised in Table 9.

The SHGC values for glazing in each façade were calculated as per the limiting FSA values in Table J1.5b and the calculation methodology specified in clause J1.5(e) and (f). Where the calculated values are impracticable (example First Floor, North Wall) SHGC values have been limited to 0.89. Fixed external louvres have been modelled as per design for both the reference buildings and the FSA has been calculated with the appropriate shading multipliers.

Wall Orientation

Bridging Material

Bridging %

Reflective Airgap

Insulation (k=0.04) Thickness mm

Total R value m2-K/W WWR

target Utotal for Wall and Glazing

North Timber 18 Yes 80 2.2 32% U 2.0South Timber 18 Yes 40 1.4 16% -East Timber 18 Yes 70 2.1 54% U 2.0

West Timber 18 Yes 70 2.1 56% U 2.0

North Timber 18 Yes 40 1.4 10% -South Timber 18 Yes 70 2.1 34% U 2.0East Timber 18 Yes 70 2.1 71% U 2.0West Timber 18 Yes 70 2.1 84% U 2.0

Ground Floor

First Floor



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Table 8: FSA calculations for Ground and First floors for the Roselands project

Solar Compliance for NCC 2019 Façade Aspect

Aw- Area of the window

m2Window

Height m P H G G/HP/H

Sw- Shading Multiplier from

Table J1.5e Aw x SwWall

Area m2

FSA (Façade Solar Admittance)

Limiting Value from Table J1.5c

SHGC = FSA x Total

Wall Area / sum(Aw x Sw)

T09 0.7 1 0 0 1 0.7Communal Room 10.5 2.1 1.2 2.1 0 0.0 0.6 0.51 5.4Unit05 5.25 2.1 1.2 2.1 0 0.0 0.6 0.51 2.7Unit09 5.46 2.1 1.2 2.1 0 0.0 0.6 0.51 2.8Totals 11.5 68.0 0.1 0.59

T06 0.45 0.3 1 0.5Corridor 7.4 2.1 1 2.1 0 0.0 0.5 0.57 4.2Corridor 1 0.63 2.1 0 1 0.6Unit06 2.6 1.45 1 2.5 1 0.4 0.4 0.94 2.4Totals 7.7 68.0 0.1 0.88

Corridor 11.19 2.1 1 2.1 0.0 0.5 0.57 6.4Unit06 5.84 1.45 1 2.5 1 0.4 0.4 0.94 5.5Unit07 5.79 1.45 1 2.5 1 0.4 0.4 0.94 5.4Unit08 5.8 1.45 1 2.5 1 0.4 0.4 0.94 5.5Unit09 1.26 2.1 1 1.3Totals 24.0 60.2 0.1 0.25

T05 0.7 1 1 0.7Unit01 8.5 2.1 1 2.1 0 0.0 0.5 0.57 4.8Unit02 8.5 2.1 1 2.1 0 0.0 0.5 0.57 4.8Unit03 8.5 2.1 1 2.1 0 0.0 0.5 0.57 4.8Unit04 7.75 2.1 1 2.1 0 0.0 0.5 0.57 4.4Totals 19.7 60.2 0.1 0.31

NCC 2019 North Wall - Ground Floor, SHGC = 0.59

NCC 2019 East Wall - Ground Floor, SHGC = 0.25

NCC 2019 West Wall - Ground Floor, SHGC = 0.31

NCC 2019 South Wall - Ground Floor, SHGC = 0.88

Solar Compliance for NCC 2019 Façade Aspect

Aw- Area of the window

m2

Window Height

m P H G G/H P/H

Sw- Shading Multiplier from

Table J1.5e Aw x SwWall

Area m2

FSA (Façade Solar Admittance)

Limiting Value from Table J1.5c

SHGC = FSA x Total

Wall Area / sum(Aw x Sw)

Bed 03 1.8 1.2 1.0 1.8Bed 08 1.8 1.2 1.0 1.8Totals 3.6 36.6 0.1 1.0

Unit01 3.6 1 1.0 3.6Unit06 1.8 1 1 1 0 0.0 1.0 0.4 0.6Unit06 2.2 1.2 device 0.4 0.8Bed 01 1 1.5 1.0 1.0Bed 06 3.9 2.6 1.0 3.9Totals 9.9 36.7 0.1 0.37

Unit06 4 1 1 1 0 0.0 1.0 0.4 1.4Unit06 4.8 1.2 device 0.4 1.7Unit07 4 1 1 1 0 0.0 1.0 0.4 1.4Unit07 4.8 1.2 device 0.4 1.7Unit08 4 1 1 1 0 0.0 1.0 0.4 1.4Unit08 4.8 1.2 device 0.4 1.7Totals 9.2 37.4 0.1 0.40

Unit01 10.4 2.6 device 0.35 3.64Unit02 10.4 2.6 device 0.35 3.64Unit03 10.4 2.6 device 0.35 3.64Totals 10.92 37.4 0.1 0.34

NCC 2019 North Wall - First Floor, SHGC = 1; Modelled as 0.89

NCC 2019 South Wall - First Floor, SHGC = 0.37

NCC 2019 East Wall - First Floor, SHGC = 0.40

NCC 2019 West Wall - First Floor, SHGC = 0.34



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Window types for U Values between 4.0 and 5.8 were modelled as single glazed aluminium framed sliding windows. Windows with lower U Values are modelled to represent double glazed thermally broken aluminium framed sliding windows.

Table 9: Summary of window performance parameters by floor and orientation for the NCC 2019 Reference building, calculated as per section J1.5

Care has been taken to specify window performance combinations that are readily achievable in practise. It is worth noting that window systems for buildings other than Class 1 (detatched homes) are procured differently from residential buildings. It is possible to select standard size, AFRC rated windows with WERS labels for residential buildings. Window systems for other buildings are more “bespoke” with the window supplier combining glass products and framing sections to achieve a specified window system performance.

4.2.6 HYPOTHETICAL PROPOSED BUILDING WALL-GLAZING AND ROOF INSULATION SELECTION

Since the case study project is still under Design Development stage, a Hypothetical Proposed Building model was created to show JV3 compliance with the draft provisions of the NCC 2019 Section J. The model represents one possible design solution that would be Section-J compliant for building envelope under the proposed NCC2019 draft provisions, but has no relationship to what the final As Built configuration will be. For this scenario, the wall total thermal transmittance has been set at R2.4 taking into the effect of thermal bridging, and the total system window glazing system performance has been set to U2.5 and SHGC 0.5. In practice, this would mean that the north and south facades to both floors would require double-glazing; whereas, for the NCC16 reference model, single glazing was all that required for the ground floor north and south facades, and for the first floor north, south and east.

Roof/ceiling insulation has been improved from R4.2 to R5.0.

NCC 2019 Reference Building Window Performance Wall Orientation

SHGC Window Uwindow WWR

target Utotal for Wall and Glazing

North 0.59 5.3 32% U 2.0South 0.89 5.8 16% -East 0.25 3.3 54% U 2.0West 0.31 3.2 56% U 2.0

North 0.89 5.8 10% -South 0.37 5 34% U 2.0East 0.40 2.6 71% U 2.0West 0.34 2.3 84% U 2.0

Ground Floor

First Floor



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4.3 DTS HVAC SYSTEM

In practise, for buildings of this size and class, a “hybrid” compliance approach is typical, and this will continue to be the case for the draft NCC 2019. In this “hybrid” compliance process, the JV3 method is used to optimise the façade, with a DTS compliant HVAC system modelled. No HVAC configuration changes are made between reference and proposed building model runs; such a procedure proves compliance of the building envelope. The HVAC (and lighting) contractor then provides a Section-J compliance certification via the DTS route for their design.

For this case study a series of DTS compliant, DX reverse cycle electric heat pumps have been modelled, one system per boarding unit, has been modelled. The system schematic is shown in the schematic in Figure 11. This HVAC configuration is referred to as a Packaged Terminal Heat Pump (PTHP) in the EnergyPlus (USDOE) energy simulation calculation engine. Since the COPs for this size of equipment is governed by MEPS (Minimum Energy Performance Standards), these values are the same for both the NCC2016 and proposed NCC2019 runs at this time.

The system schematic shows an outside air section, DX cooling and heating coils, a fan section, and an electric defrost/heating coil. Figure 12 to Figure 14 are screen captures of the detailed input required. The system uses electricity for both heating and cooling, and is common in buildings of this size, in this climate zone.

A summary of important clauses in Section J5 considered for DTS compliance of the DX HVAC system (for the proposed NCC2019 clauses) are discussed below:

Each unit can be individually controlled; the thermostat is set to 21C for heating and 24C for cooling; there is no mixing of hot and air streams, nor is reheating applicable for this system configuration; the individual PTHP sizes are well below that required for economy cycle (varying from less than 0.6 kW to about 3 kW), so only minimum fresh air is modelled; being a packaged system a constant speed fan is modelled. No pumping or water based requirements need be considered. No ducting requirements were considered as each DTS compliant PTHP system was modelled as having an in-room fan coil unit that delivers conditioned air directly into the space, without any ducting. The only consideration really is to ensure that the fan wire-to-air efficiencies meet or exceed the J5.4 requirements, using the equation in clause (b) (ii), and the MEPS compliant systems modelled were calculated to comply with DTS requirements.

The DX HVAC systems were auto-sized for each run based on a selected set of monthly design day temperatures and coincident wet bulb temperatures. Part load performance curves adjust the efficiency of the PTHP system based on capacity, as well as on supply air and environmental conditions.



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Figure 10: PTHP System as represented in DesignBuilder / EnergyPlus

Figure 11: DX cooling coil input as represented for 2019 Reference Building in Energy Plus. Whereas the NCC 2016 specifies a night time use schedule for HVAC for a class 3 building, the draft NCC 2019 code requires the HVAC plant to be operated based on the occupancy schedule.



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Figure 12: Packaged terminal Heat pump inputs

Figure 13: Supply Fan Inputs



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4.4 (J1.6) LIGHTING

As noted earlier, the focus of this case study is on testing compliance of the building envelope using a “hybrid” JV3 Verification Method approach. Therefore, the lighting system design is not considered for this case study. However, the lighting power densities allowed under the respective codes have been input to the respective NCC reference building models for the purpose of testing building envelope compliance.

A summary of the lighting power density calculations for both NCC2016 and proposed NCC2019 codes is listed in Table 10 after adjustments for the room aspect ratio. Lighting adjustment factors are not considered for either building model, as the lights are assumed to be manually switched as is generally the case for this class of building.

Table 10: Lighting Power Density comparison for DTS provisions of NCC 2016 and draft NCC 2019 for Class 3 building

The calculations show that LPD values for the proposed NCC2019 are much more stringent than in NCC2016, and will result in a significant reduction in GHG emissions from the NCC2019 Reference building model.

4.5 SIMULATION PARAMETERS

4.5.1 MODELLING PARAMETERS

Table 11 captures the differences and similarities for many of the internal load and operational inputs to the simulation model between the existing NCC 2016 clauses and those proposed for the draft NCC 2019, as applicable to this case study. Infiltration has been reduced, thermostat settings for cooling and heating have been tightened (to reflect practise).

In summary, infiltration rates have been reduced, thermostat settings for cooling and heating have been tightened (to reflect practise). Equipment and occupant loads are the same for both codes.

Room TypeRoom Height Area Perimeter

Room Aspect ratio

NCC 2016 nominal LPD

Adjusted for Room aspect ratio (simulated)

NCC 2019 nominal LPD

Adjusted for Room aspect ratio (simulated)

Unit 01 - 03, 06-08 5.0 18.5 17.2 0.21 5 8.7 2.5 4.4Bed 01-03, 06-08 2.6 11.4 13.6 0.32 5 8.2 2.5 4.1Entry 01-03, 06-08 2.4 5.3 9.4 0.24 8 13.8 2.5 4.3T01-03, 06-08 2.4 7.3 10.6 0.28 5 8.4 2.5 4.2Unit 04 2.4 23.8 26.6 0.37 5 8.0 2.5 4.0T04 2.4 7.3 10.6 0.28 5 8.4 2.5 4.2Unit 05 2.4 36.0 29.5 0.51 5 7.5 2.5 3.7T05 2.4 7.3 10.6 0.28 5 8.4 2.5 4.2Unit 09 2.4 26.3 25.4 0.43 5 7.8 2.5 3.9T09 2.4 7.3 10.6 0.28 5 8.4 2.5 4.2Communal Room 2.4 21.3 24.8 0.36 10 16.1 3.0 4.8T Communal 2.4 7.3 10.6 0.29 6 10.1 2.0 3.4Corridor 2.4 38.0 25.2 0.63 8 11.3 2.5 3.5



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Table 11: All other inputs, comparison between DTS provisions of NCC 2016 and draft NCC 2019

4.5.2 MODELLING PROFILES

Figure 14: NCC 2016 Class 3 Schedules

Figure 15: Draft NCC 2019 Class 3 Schedules

Building Element NCC 2016 DTSModel Input NCC 2016 Reference building NCC 2019 DTS

Model Input NCC 2019 Reference Building

Equipment Class 3 5W/m2 averaged; 8760 h y

5W/m2 averaged ; 8760 h for sole occupancy unit. Elsewhere as per schedule y

Occupancy 75W &55W y 75W & 55W yDensity 15m2 / person y 15m2 / person y

Infiltration

1.5ACH when plant is OFF in all zones1 ACH for perimeter zones and 0 for center zone when plant Is ON y

0.7 ACH when plant is OFF for all Zones0.35 ACH when plant is ON for all zones y

Thermostat18 to 26 to all conditioned zones y 18-25 to transient zones y

21-24 to all other zones ySchedules NCC 2016 Specification JV y NCC 2019 Sepcification JVc y

0%

20%

40%

60%

80%

100%

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

Draft NCC 2019 Class 3 Schedules

2019 All Days Lighting2019 Equipment for All other areas2019 All days HVAC



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Class 3 modelling profiles (or time of use schedules) as described in the NCC 2016 and draft NCC 2019 are shown above, and are used for the simulation runs. The difference in operational schedules impacts interior equipment energy use numbers the most, as seen in the results.



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5 RESULTS AND CONCLUSIONS Table 12: Modelled results for Roselands boarding house project

Run Plan NCC 2016 Reference Building

GFA 386m2

NCC 2019 Reference Building

GFA 386m2

NCC 2016 ENV +NCC 2019 LTG + SIM

GFA 386m2

Proposed Hypothetical Building

GFA 386m2

Run Description

Reference building with NCC 2016 DTS compliant Envelope (J1 and J2), HVAC J5, Lighting J6 and NCC 2016 JV3 Sim Parameters

Reference building with NCC 2019 DTS compliant Envelope J1 , HVAC J5, Lighting J6 and NCC 2019 JVc SIM Parameters

Interim Run with NCC 2016 DTS Envelope, and NCC 2019 compliant HVAC J5, Lighting J6 and NCC 2019 JVc SIM Parameters

Improved Building with a hypothetical proposed Envelope and NCC 2019 compliant HVAC J5, Lighting J6 and NCC 2019 JVc SIM parameters

EnergyEnd Uses kWh kWh/m2 kWh kWh/m2 kWh kWh/m2 kWh kWh/m2

Heating 2,150 5.6 3,856 10.0 4,940 12.8 3,846 10.0

Cooling 642 1.7 1,941 5.0 1,755 4.5 2,102 5.4Interior Lighting 15,248 39.5 11,105 28.8 11,105 28.8 11,105 28.8Interior Equipment 16,923 43.8 15,325 39.7 15,325 39.7 15,325 39.7Fans 2,056 5.3 3,353 8.7 3,499 9.1 3,004 7.8

Total End Uses 37,019 95.9 35,579 92.2 36,623 94.9 35,381 91.7

Total HVAC 4,848 12.6 9,149 23.7 10,193 26.4 8,951 23.2

Greenhouse Gas Emissions kgCO2-e /GJ 35,316 91.5 33,942 87.9 34,938 90.5 33,753 87.4% over 2019 REF Allowance 4% 0% 3% -1%



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The above results are for the three building simulation models developed for the Roselands boarding house project described earlier (and reproduced below).




A fourth interim modelling run has also been added (in blue) which reviews the performance of the building when fitted with the NCC2016 building envelope, but modelled with all other systems and modelling requirements from the proposed NCC2019. This run tests the response of the NCC2016 building envelope when modelled with the proposed NCC2019 code provisions.

5.1 ENERGY/GHG EMISSIONS

The results indicate that, for the case of the proposed Roselands boarding house project:

1. There is a predicted 4% reduction in GHG emissions between the compliance requirements of NCC 2019 Reference Building and that of the NCC 2016 Reference Building. Buildings similar to the proposed Roselands boarding house project in climate zone 5 would be impacted in this manner, which includes Sydney, Perth and Adelaide, all of which are heavily populated areas in Australia

2. Comparing the predicted results from the interim runs (the green and blue columns) indicate that the proposed NCC2019 building envelope stringencies are higher that of NCC2016. For the proposed Roselands boarding house, the NCC2016 building envelope is predicted to release 3% more GHG emissions than the NCC2019 Reference Building.

3. Double glazed windows and improved roof insulation could be specified (as described in section 4.2.6) to reduce GHG emissions from the Proposed Hypothetical Building model to pass the NCC2019 Reference Building allowance. These changes to glazing, wall and roof/ceiling are predicted to reduce emissions to 1% below the NCC2019 Reference Building levels

4. This result should not be generalised, and should be tested for other NCC Class of buildings in other climate zones. However, the results seem to indicate that smaller, Class 3 buildings, in climate one 5, have a small increase to building envelope stringency requirement under the proposed NCC2019 provisions.



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5.2 COST IMPLICATIONS

Capital cost implications of the proposed NCC 2019 initiatives for this case study would mainly be in the areas of building envelope and LED lighting.

5.2.1 WINDOW SYSTEMS

The glazing selection for the NCC2019 Reference Building model indicate that the minimum window specifications for the proposed Roselands boarding house project to comply with the proposed NCC2019 provisions require the performance of some of the windows to be increased to high performance double glazed systems (U2.5 and SHGC 0.5), when compared to the existing NCC2016 provisions. The additional cost on this project is estimated to be in the range of $50,000 - $75,000

5.2.2 LED LIGHTING

In the case of LED vs CFL lights, LEDs are marginally more expensive at this time, but prices are reducing steadily. It is conceivable that by the time the proposed NCC2019 legislation is implemented, LEDs will be the technology of choice. At this point, the cost differential for a standard 90mm LED downlight fitting with dimmable driver is about 2 – 4 times the cost of an CFL lamp which can fit into a standard (incandescent) lamp mount. Payback has been estimated at 3 – 5 years. Labor cost for installations of either type of downlight are comparable. LED fittings that are “IC” rated are already available in the marketplace. These fittings can have insulation installed directly over them, without the need for cutting holes in the insulation on the ceiling. This one characteristic alone would reduce heating energy consumption, by reducing heat loss from the ceiling in winter. Such fittings would be very beneficial for projects like the proposed Roselands boarding where the energy consumption for heating can be twice as high as for cooling (night operating buildings in moderate climates).

6 CONCLUSIONS The analysis finds that, for the case of the proposed NCC 2019 JV3 compliance requirements (NCC 2019 Reference Building), there is a small but significant reduction in the predicted annual GHG emissions when compared to the 2016 JV3 compliance requirements. There is a predicted 4% reduction in GHG emissions between the proposed NCC2019 Reference Building and NCC2016 Reference Building models. There is also a predicted 3% reduction between a the NCC2019 Reference Building model and the “interim” model, once fitted with NCC2016 building envelope, but with all NCC2019 modelling parameters and modelling profiles. This is a clear indication that building envelope requirements in the NCC2019 are slightly more stringent.

Finally, it is reiterated that the proposed Hypothetical Building model provides one possible compliance solution, in which the window system performance specifications and the ceiling/roof insulation levels were made more stringent to show compliance with the proposed NCC2019 provisions.

case study – ncc 2019 proposed upgrade · the analysis finds that, for the case of the proposed...

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