RESIDENTIAL DTS (DEEMED TO SATISFY)
A Section 3.12 – Deemed to Satisfy (DtS) report provides a list of prescriptive insulation values and thermal properties for single dwelling houses that use common construction materials and methods.
The Section 3.12- DtS report is elemental provision including the minimum Total R-Values of roofs, walls and floors, the glazing allowances and the air movement requirements.
It is simple, low cost, and can usually be delivered in a single business day. However, there are some limitations to DtS that we discuss in this page.
At Energy Compliance, we offer all avenues to demonstrate your building compliance under any conditions.
What is covered in a section 3.12 DTS report?
Australia’s building code seeks to minimize the energy demand of commercial built spaces to minimize their carbon footprint. The BCA energy efficiency requirements take into account the following:
Roof and Ceiling construction
Walls and glazing
Click on the highlighted numbers in the following figure to see the energy efficiency requirements for a typical residential building.
NCC Energy Efficiency Deemed to Satisfy requirements for typical residential building (class 1a) in Melbourne (climate zone 6) - Click on each component to see the minimum requirements.
The core of a Section 3.12 report, is a short table that outlines the minimum applicable thermal performance parameters – mainly to the building fabric and building services. This information is the minimum required for compliance. At Certified Energy, we also illustrate the location and value of the added insulation required to make sure there is no communication error between the design and construction team.
Below is a sample extract of the DTS requirements for a residential building – Class 1 building in Climate zones 5 and 6, (Sydney and Melbourne) for example.
1 (single detached dwelling)
Roof solar absorptance
Wall with major glazing
Wall with minor glazing
Wall solar absorptance
Windows overall U value
There is no mandate on this, however, NCC allows offsetting carbon emission from building with onsite renewable energy
Mechanical ventilation and exhaust
Minimum chiller efficiency
Notes: SHGC (Solar heat gain coefficient): the ratio of solar heat gained through the building’s window to the total irradiation on the window
Section 3.12 of the National Construction Code (NCC) Volume 2, or as it was formerly known, the Building Code of Australia (BCA), applies to all residential buildings (Class 1 – residential dwelling, and Class 10 – unoccupied spaces like a garage or shed).
· More design iterations performed to reduce construction costs.
· Realistic design assumptions used to better resemble actual building performance and save construction costs.
· Innovative 3D building modelling tools used to achieve the best quality control.
· Superior energy reports provided: Building plans are marked-up to show the proposed changes, saving the architect and/or builder considerable time. Amended cross section drawings are provided for each effected type of wall, roof and floor.
· If we can’t reduce your construction cost by more than our fee, we’ll only charge 25% of our full fee.
· Quotations – Same business day ofenquiry.
· Deemed to Satisfy (DTS) reports – Within 1-2 business days.
· Energy Rating – Within2-3 business days.
· Performance-based solutions – (JV3 and Reference Building method) – 1 to 2 weeks.
We illustrate energy efficiency DtS report
At Energy Compliance, we want to be better than our competitors and that is why we put time to illustrate the added insulation to all sections of the building. This way, the building construction and planning team can make sure that there is no miscommunication between parties by use of energy efficiency jargons.
PROCESS AND DURATION TO GET YOUR SECTION J DTS REPORT
If we get all the required information from client, we might be able to finish DTS report in a single business day. The following shows the typical process.
Geoflow provides quotation
Client signs the professional service agreement
We discuss client’s energy targets and limitations
Geoflow provide the draft report
Client reviews report, and we discuss any alterations to the report
The final report is issued
Payment is made.
1-3 business days
1 business days
1 business day
What are limitations of residential DtS energy compliance?
DtS energy compliance is a low cost and fast compliance avenue to National Construction Code. At Energy Compliance we always recommend DtS solution first as it is low cost. However, as it is prescriptive, it is very strict. For instance, under DtS for residential, you might be required to add a small R value to your existing polished concrete floor. Under the DTS energy compliance method, you commit to follow the NCC minimum requirements and you cannot skip anything.
Another example is the fact that glazing requirements under DTS are always the most expensive options. This is due to the fact DTS glazing calculator only looks at glazing as an individual item, and doesn’t consider the holistic performance of the entire building. This results to very expensive glazing requirements that doesn’t necessarily mean better overall energy performance at a similar cost.
What are alternatives to DTS?
NCC offers an alternative Energy Compliance method which considers holistic building performance! This, importantly allows us to consider the interaction between all the different parts of the building fabric, and to improve some parts by assigning alternative, lower cost DTS thermal performance requirements to the rest of the building.
NCC allows utilising simple modelling method, NatHERS star rating or the performance-based Verification Using Reference Building (VURB) method.
NatHERS star rating is recommended for small and median size houses.
VURB is recommended for high end houses, with large footprint and high glazing area. This method essentially provides flexibility in how to achieve Energy Compliance and reduce construction costs.
Who needs a residential energy DtS report?
All new buildings and major renovation/extension require construction to the minimum energy efficiency standards in National Construction Code. For renovation/extension bigger than a threshold specified by different states, the whole house should also brought up to the current standards. As a first step in energy compliance, you will need to obtain a report (such as Section 3.12 Volume 1 – Deemed to Satisfy Report) demonstrating compliance to National construction code.
A Section J compliance report is part of the documentation required when applying for a building permit. The report is used by the building surveyor to satisfy your local council requirements.
Who can deliver a deemed to satisfy report?
You can do it yourself, or get a qualified mechanical engineer with similar experience background to produce a residential DTS report. Highly qualified mechanical engineers with an in-depth understanding of building services and building materials, with experience in the NCC, are the people who can best identify energy cost saving opportunities and reduce construction costs while satisfying energy compliance requirements.
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