HIA’s Peter Zagorski: NCC Changes & Challenges

HIA Update & What to Expect in 2024

The National Construction Code (NCC) update coming into effect from 1st May 2024 is relatively large and can mean some builders and homeowner will need to do a substantial amount of work to meet the new requirements. Bowens spoke with Peter Zagorski, Director of Building Services at the HIA, to get some clarity around issues that will impact builder the most.

When it comes to the NCC changes being implemented for the 1st May, what do you foresee as the change that will impact builders the most?

Across the board I would say 7-Star and the Whole-of-Home energy use budget will have more of an impact on the builder. Depending on the orientation of the house and the size of the house will have an impact on the type of windows, amount of insulation etc. that needs to be provided. I would be saying to any member when their clients sign their preliminary agreement, get the energy assessor involved so they indicate what may need to change, be added to meet the requirements prior to the building permit stage.

“Across the board I would say 7-Star and the Whole-of-Home energy use budget will have more of an impact on the builder.”

The livable housing requirements asks for the increase in door openings and hallways including toilets for accessibility, among a range of other changes. What sort of impact do you feel this might have on builders?

Hopefully many builders would be aware of these proposed changes from HIA’s seminar series and would have commenced working on their standard house designs to meet the proposed provisions. The main area of concern we have received from members is meeting the access provisions, the step free pathway and step free entry. The increase in door widths and hallways/passageways will need careful consideration as it will reduce the overall size of the habitable rooms. Passageway through a WIR to an ensuite that contains the step free shower will need to be a clear width of 1000mm. Whoever prepares the plans will also need to make it clear how things like dimensions are specifed. If we take the WC provisions for example, it says that the clear width of the WC room must be 900mm between the plasterboard, not between the frame. If the dimension on the plan is shown as 900mm, once the plasterboard goes on you’ve suddenly only got 880mm and it doesn’t comply. This might catch some builders out.

“The main area of concern we have received from members is meeting the access provisions, the step free pathway and step free entry.”

Can you please explain what the whole-of-house (WOH) annual energy use budget is and can you see any major flaws with its implementation?

Basically, it is a score out of 100 with a minimum requirement of achieving 60 using the online modelling tools. It takes into account appliances such as, heating and cooling, heated water systems, pool pumps, lighting and solar panels. This will mean that the client will have to decide on all appliances before you apply for your building permit and engage your energy assessor. 

Before you can determine the modelling for WOH energy usage, you need to meet 7-star building fabric otherwise the modelling tool can’t model the WOH. If the star rating is saying 6.8 star the WOH calculation will need the determined using the elemental provisions in the NCC. (I.e the ABCB WOH calculator)

“Before you can determine the modelling for WOH energy usage, you need to meet 7-star building fabric otherwise the modelling tool can’t model the WOH.”

What are the key factors for builders to take away from the new ventilation and condensation requirements?

Key factors that will need to be considered will be the selection of the pliable building membrane (PBM). In Climate zones 6, 7, 8 the vapour permanence of the PBM must be 1.14 μg/N.s. (Class 4).

Exhaust systems of rangehoods, bathroom, laundry and toilets will have to be ducted to the outdoor air. Ducting into the roof space will no longer be permitted. 

“Exhaust systems of rangehoods, bathroom, laundry and toilets will have to be ducted to the outdoor air. Ducting into the roof space will no longer be permitted.”

Rooms without windows or natural ventilation will also need to consider obtaining make up air from an adjoining room. This will have an implication on how and where duct work needs to be installed particularly where there is an internal kitchen or toilet on a lower storey. The ductwork will need to either be placed within the ceiling space or bulkheads may need to be installed. The other key factor will be meeting the roof space ventilation requirements. Depending on the pitch of the roof the NCC specifies minimum ventilation openings at the upper and lower ends of the roof. If sarking provided in the roof, then it must have a vapour permanence of 1.14 μg/N.s.

Do you think we will see a rise in people moving towards custom homes and a more individualised approach to building? 

I don’t see this as being a huge issue. The beauty about volume builders is that they already have everything in place such as their designs and cutting lists, so it’s a matter of minor changes in a lot of cases to meet the new requirements. There may be situations where the individual builder will have to sit down with their clients and customise a house to meet the client’s needs.

“There may be situations where the individual builder will have to sit down with their clients and customise a house to meet the client’s needs.”

As long as the block isn’t too problematic, then most standard designs should be fine. It’s when you’ve got a difficult site such as orientation, difference between the footpath level and where the house is going to go to provide the access for livable housing requirements, etc. that individual design will be needed. Then you’d have to start developing more of a bespoke house than just the off the shelf plan. 

Is there any information that relates to these NCC changes that builders need to relay to clients prior to signing contracts?

Builders should be advising new clients of the changes that are coming into effect on the 1st of May and how it will affect the home and its design. The builder will need to advise the client that they have to pick their appliances upfront. If they change any appliances down the track, it may require going back to the building surveyor to amend the plans if it affects the Home Energy usage. 

If you could give builders one main takeaway or advice when it comes to implementing these changes, what would it be?

I think the one main takeaway would be is, be upfront with the client, tell them what the changes are. The governments haven’t really got out there to the consumers and said, these are the things that are going to affect you. So I think the builder really needs to talk to the client, work with the client, make the client aware of what needs to be done. It’s going to be challenging to meet all the requirements in a lot of cases. You may get a client that says, “well if you can’t do it for me, I’ll go somewhere else.” However, they will be met with that same blockage with another builder. 

“(…) be upfront with the client, tell them what the changes are.”

What is the HIA doing to support the industry with these changes? For example, any workshops or seminars coming up to provide builders with more information?

We currently do monthly webinars on waterproofing, using the NCC volume Two, timber framing and livable housing provisions. We are also doing webinars on energy efficiency and condensation management next month leading up to the 1st of May. 

These can be found on our website: https://hia.com.au/careers-and-learning/learning/training-courses

For more information on the latest NCC changes, contact the HIA in Victoria or your state or territory.