Author: admin_thermalperformance

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What is a Building Envelope?

A building envelope is the physical barrier between the conditioned (internal) and unconditioned (external) environment of a building. It includes the floors, walls, windows & doors, ceiling & roof.

The building envelope contains three main layers or barriers;

  1. Water Control Layer or Weather Barrier (WRB)
  2. Thermal Barrier or primary insulation layer
  3. Air Barrier (IAB)

Depending on the design, the location, materials specified and how well the building is built will determine how well your building envelope performs.

The building envelope plays a crucial role in a building’s energy efficiency. In winter, it helps prevent the transfer of heat from inside to outside (heat loss), and during summer it keeps the cool air inside (saving the occupant $) and reduces the heat coming through windows (heat gain).

Think of it like;

  • Weather barrier keeps the rain & wind out.
  • Thermal barrier keeps the heat in with bulk insulation and the heat out with reflective insulation.
  • Window shading & types of glass work with the thermal barrier.
  • Air barrier stops uncontrolled air movement which keeps the internal temperate comfortable by reducing warm air out or cold air in.

If you would like assistance with your project, please what services we can provide!

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Group Homes, Class 3 & BASIX

Is a BASIX Certificate required for a Group Home?

Well yes & no (glad that clears it up)! it depends on your Certifier, hence they are more than likely going to require one.

The BASIX website provides the following advice Alternative assessment – Large boarding house | Planning Portal – Department of Planning and Environment (nsw.gov.au). This states a boarding house or more than 12 people or more than 300m2 is NOT a Basix development.

You will note that BASIX refers to the Environmental Planning & Assessment Regulation.

The EP&A Regulation does not specifically refer to a Group Home.

Under the BCA a group home is a Class 3 building i.e. boarding house (unrelated people).

BASIX advises specifically for boarding houses (but doesn’t use the terminology class 3).

The EP&A Regulation uses the terminology hotel, motel, boarding house, hostel or co-living housing and then adds the BCA conditions of more than 12 people or more than 300m2.

Good luck!

it will come down to the individual Certifier and the interpretation of group home verse co-living housing.

Co-living housing

Co-living housing was introduced to the NSW planning system when the Housing SEPP was made in November 2021.

Under the Housing SEPP, the definition of co‑living housing:

  • is subject to similar built-form development standards as boarding houses
  • must provide a primary place of residence for all occupants – it may not be used for short-term tourist and visitor accommodation
  • may have as few as 6 private rooms (but most co-living housing developments will typically have about 30 to 40 private rooms)
  • must provide indoor and outdoor communal space for residents to relax and socialise
  • must have a manager, who will be responsible for implementing the plan of management for the property. The manager does not have to be always on site but must be contactable by phone 24/7.

Sounds like a group home to me, but hey some will interpret it differently!

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What is a BASIX Certificate?

A BASIX (Building Sustainability Index) Certificate is a document generated online that identifies the sustainability features required to be incorporated in the building design.

BASIX aims to create more comfortable and cost-efficient homes by reducing greenhouse gas emissions and water consumption.

BASIX covers four topics:

  1. Water: The water section of the BASIX assessment examines the water efficiency of the appliances and fixtures, the design of the landscaping, and the use of alternative water sources in the development.

  2. Thermal Performance: The thermal performance section of the BASIX assessment examines the design and materials used in the building to reduce the need for artificial cooling and heating to keep the home comfortable. A NatHERS Certificate can be used to meet the requirements of the thermal performance section.

  3. Energy: The energy section of the BASIX assessment examines the energy efficiency of the appliances and equipment, and the use of alternative energy sources in the development.

  4. Materials: The material section of the BASIX assessment examines the embodied energy of the specified material and encourages less carbon intensive material to be used in the development.

The targets or requirements to pass change depending on location, climate & fuel sources selected.

If you’re building a new home, undertaking renovations of $50,000 or more, or installing a pool or spa of more than 40,000 litres, you will need a BASIX certificate. Talk to Thermal Performance if you need assistance with a BASIX certificate.

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What is NatHERS

The Nationwide House Energy Rating Scheme (NatHERS) is an Australian initiative that provides energy ratings for new dwellings.

It aims to create energy-efficient, resilient, and comfortable homes for the future that cost less to run.

Here are some key points about NatHERS:

  • NatHERS provides a star rating out of ten based on an estimate of a home?s potential heating and cooling energy use.
  • The NatHERS scheme has been upgraded to provide world-leading measurement tools that the building sector can use to support the move to net zero emissions by 2050.
  • NatHERS can now rate the energy performance for the whole home including major appliances, solar panels, and batteries, in addition to the star rating for the building shell.
  • NatHERS provides a streamlined pathway to meet or exceed the new National Construction Code (NCC) 2022 energy efficiency requirements.
  • The minimum requirement for new houses and apartments is 7 stars (out of 10).
  • A new annual energy use budget will also apply, to account for a home?s major fixed appliances and any energy generated from solar panels/PV.
  • NatHERS is administered by the Department of Climate Change, Energy, the Environment, and Water on behalf of the states and territories.

For more information, you can visit the official NatHERS website.

Contact us for for help, assistance, questions or to arrange a NatHERS simulation or certificate.

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What is a Blower Door Test

A blower door test is a diagnostic procedure used to measure the airtightness of buildings.

It can identify air leakage and help improve energy efficiency.

During the test, a blower door fan is mounted into an external doorway, and either pressurises or depressurises the building to reveal unsealed cracks and openings through which air can enter or escape (infiltrate or exfiltrate).

This process is crucial for determining how much air leaks in or out a home, which can impact heating and cooling costs, comfort levels, and indoor air quality.

Professionals use this test to recommend improvements and ensure that heating and cooling systems are properly sized. The results of a blower door test can guide homeowners in making targeted upgrades to enhance their home’s energy performance and comfort.

Here’s how it works:

  • The blower door fan depressurizes the house by pulling air out, which lowers the indoor air pressure.
  • The higher outdoor air pressure then flows in through all unsealed cracks and openings.
  • A pressure gauge, called a manometer, measures the pressure differences inside and outside the home.
  • The rate at which air infiltrates the home is recorded, often in terms of Air Changes per Hour (ACH).
  • The test can also be conducted in reverse, with the fan blowing air into the house to create positive pressure. During the test, professionals may use an infrared camera or a smoke pencil to detect the specific locations of air leaks.

Blower door tests are important for several reasons:

  • They help reduce energy consumption due to excess air leakage.
  • They prevent moisture condensation problems and uncomfortable drafts.
  • They control the entry of outdoor contaminants, pests, and odours.
  • They assist in determining the proper sizing of heating and cooling equipment.
  • They indicate whether mechanical ventilation is needed to maintain indoor air quality.

If you would like to arrange a Blower Door Test or have any questions, please contact us!

ATTMA | Registered Air Tightness Testers – Australia (bcta.group)

ABCB Building Code Building Sealing Verification

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7 stars – BCA 2022

October 2023 we will need to achieve 7 stars for new homes.

Designers, Architects & Builders work out how long it takes from initial client meeting to getting DA for your past projects and see when you need to adjust designs for 7 stars.

It is going to be drastic!

Doing what you want and thinking insulation and some window upgrades will get the pass won’t work any more.

7 stars will probably mean;

  • Living areas and importantly windows in living areas face north
  • Waffle pod slabs
  • R2.5 wall insulation
  • R6.0 ceiling insulation
  • Insulating joists over garages & Alfrescos
  • Low e glass, ceiling fans & shade devices for cooling
  • Double glazing for heating

Windows will be the problem and result in very high expense!

Check your glass to floor ratio (area of windows in elevation divided by the floor area) works for a room or the whole house, up to 30% won’t be to bad, higher than this and it will be very expensive to achieve 7 stars.

Good thermal design has;

  • 50% of the north facade as glass
  • 15% of east & west facades as glass
  • 10% of south facade as glass

If you are not close to the above numbers this is where to start improving the design to achieve 7 stars at a lower cost!

If you would like assistance or advice with meeting the 7 star requirement, please get in contact with us!