Building engineering

In Australia, research for the Australian Sustainable Built Environment Council (ASBEC) suggests that the building sector is directly responsible for around 24% of the total energy use. At present this is split fairly evenly between the residential and commercial building sectors. Reducing energy use and reducing greenhouse gas emissions are both worthwhile goals as it saves money and saves the environment. Reducing greenhouse gas (GHG) emissions has been presented with increasing urgency within recent years as it is driving climate change.

There are many opportunities to reduce energy and emissions within the building sector. Governments and industry groups are preparing for enhanced energy efficiency. Some matters are currently required by the Building Code of Australia (BCA 5 star, BASIX for NSW) & others are becoming so. (eg. NABERS Energy) Along with these mandatory regulations voluntary schemes are also available. (Green Star, GreenPower). Below I will discuss these mandatory legislative & planning requirements as well as optional solutions for thermal efficiency.

In Australia, there are currently two building regulations to control the efficiency of design for a new home or renovation: Building Codes of Australia (BCA) – Under the current BCA, all new homes in Australia (except New South Wales) are to be designed to be rated at 6 stars for thermal efficiency. A BCA Section J Report is required by local councils and building authorities when applying for a building permit or Construction Certificate (CC).

The BCA Section J Report is a document which shows how the proposed building complies with the relevant Energy Efficiency requirements of the Building Code of Australia (BCA). BCA Section J Report includes: Part J1| | Building FabricThe building envelope must meet minimum total R-Value requirements| Part J2| | GlazingAggregate air-conditioning value attributable to glazing must not exceed nominated allowances| Part J3| | Building SealingSealing requirements for chimneys, flues, exhaust fans, building elements, windows and doors| Part J4| | Not applicable|

Part J5| | Air-conditioning and Ventilation SystemsRequirements for air-conditioning and ventilation systems| Part J6| | Artificial Lighting and PowerRequirements for lighting and power energy consumption| Part J7| | Hot Water Supply and Swimming Pool and Spa Pool PlantMinimum requirements for hot water systems, swimming pools and spas| Part J8| | Access for Maintenance and Facilities for MonitoringMaintenance requirements and monitoring of energy consumption for larger buildings| Building Sustainability Index (BASIX) – In New South Wales, all new homes are required to pass BASIX.

BASIX scores water, energy and thermal comfort. BASIX is a planning initiative of the NSW Government that requires all new dwellings to be designed and built to achieve a 40% reduction in water consumption and 40% reduction in greenhouse gas emissions compared to the average dwelling. That is, new dwellings have to use less water and be more energy efficient. Similar to the BCA section J report, a BASIX report must submitted as part of the DA.

There are three metrics that are being evaluated in order to get a BASIX certificate BASIX water In order to get a BASIX certificate for a new dwelling in NSW the average water consumption of that dwelling must not exceed the target specified in the BASIX online tool.

BASIX thermal comfort This category of the BASIX deals with the evaluation of the performance of a house to stay comfortable throughout the year by consuming the least amount of energy for heating it in winter (Heating load) and cooling it in summer (cooling load). This BASIX rating element is on a Pass/Fail basis and there are three methods currently applicable to get a pass result from thermal comfort section of the tool.

* Rapid method which only applies for single storey detached simple dwellings with typical construction elements. * DIY Method which is for a single dwelling with little flexibility and introduces minimum insulation and window performance requirements to the BASIX certificate.

* Simulation Method which is a detailed and flexible thermal simulation applicable to single and multi unit developments and must be performed by an ABSA Accredited Assessor. BASIX energy Like water score, BASIX energy score is also dependent on the location of the development as well as the building type.

While every new dwelling needs to meet the minimum energy efficiency requirements, more than 80% of all new developments must meet maximum energy targets specified in the BASIX online tool in order to get a certificate. Household use of solar photovoltaic (PV) panel systems has grown significantly in Australia this decade behind increased awareness of the risk of dangerous climate change, the reduced cost of systems and a range of government incentives to encourage use of the technology.

* Solar power systems are now an affordable option for Australian households looking to reduce their power bills and generate their own clean electricity. * Solar Energy helps reduce your carbon footprint as it is a clean energy alternative. * Solar Energy does not contribute to global warming, acid rain or smog. * Solar Power therefore, actively contributes to the decrease of harmful green house gas emissions. * Less pollution in the air means cleaner air for us to breathe, therefore increasing our life expectancy. * Solar energy is currently only a small percentage of our total energy use.

You are helping Australia to achieve its 15% green energy target by 2020 and global targets of 20% at the same time by switching to solar power. * Solar Power is Quiet. In fact, solar panels are silent. They convert sun light into electricity without making a sound.

* Solar Energy systems are virtually maintenance free and will last for many years. QUESTION 2 The Building Code of Australia Volume one provides energy efficiency requirements for class 3 to 9 buildings in Section J, Energy Efficiency. For commercial buildings, a BCA Section J report needs to be compiled in order to show building’s compliance.

Unlike other sustainability schemes like BASIX, GREENSTAR or NABERS, a BCA Section J report provides no standard format for compilation. However there are many organisations with highly developed calculator sheets that cover many sections of BCA Section J that are used to compile reports. Part J1 to J8 of BCA section J nominate energy efficiency provisions required for class 3 to 9 buildings in the following areas:

* Building fabric and thermal properties of envelope material * Windows, skylights and glazed doors * Sealing against heat loss and heat gain * Performance requirements of air movement systems * Air conditioning and ventilation systems * Power restrictions for artificial lighting of the building * Requirements for hot water supply of the building * Access requirements for service and maintenance BCA Part J design requirements can be verified with respect to small commercial buildings by abiding by minimum standards set out in BCA section j energy efficiency ‘deemed to satisfy ‘provisions. The below table demonstrates ‘BUILDING SEALING J. 3 requirements’

BCA clause| | MINIMUM COMPLIANCE FOR EACH SECTION| PROPOSED BUILDING| J 3. 1| Application of part| Buildings mechanically conditioned are to be sealed Excluding – where the only means is evaporative cooling, or there is sufficient pressurisation to prevent infiltration, or parts of buildings that cannot be fully enclosed. | The conditioned building envelope is to be sealed Note: existing building | J 3. 2| Chimneys / flues| Chimneys & flues to have dampers| N/A| J 3. 3| Roof lights| all roof lights must have capability ofbeing sealed| Roof lights are sealed| J 3.

4| Windows / doors| All external doors and windows leading into a conditioned space must be sealed, exceptions to windows complying with AS/2047, fire doors and roller shutters | External swinging doors to have air infiltration seals; and All windows sealed as per manufacturers standard| J 3. 4d| An entrance to a building | Must have an airlock, self-closing door or the like if leading to a conditioned space >50m2| Self-closing door has been provided to main entry. N/A – D03, D04 conditioned space < 50m2| J 3.

5| Exhaust fans| Within a conditioned space must be fitted with a sealing device| all new exhaust fans to have self-closing dampers| J 3. 6| Roof / walls / floors| Building construction required to minimise air infiltration| New construction Gaps & cracks sealed in accord with J3. 6 | J 3. 7| Evaporative coolers| Must be fitted with self closing damper when serving a heated space, or in a habitable room or public place in Climate zone 4 to 8 | If fitted must have self closing damper| QUESTION 3 BCA Part J compliance has become an essential part of construction practice.

Mandatory requirements are now in place & will continue to arise as new technology paves the way for complete energy efficiency. It is therefore important that steps are taken early on in the development process to achieve legislative compliance. Steps include: * Consulting experts regarding section J report * Have all reports & documents ready for submission * Send through accompanying design documents for a Development Application * Amend if necessary * Begin construction process * Ensure all requirements under section J report are met throughout construction * Achieve final construction certificate with complete compliance