Western Sydney custom build: solar passive

In 2020, I posted a custom design and was interested in feedback regarding solar passive principles. The overwhelming feedback wasn't positive and based on the quality of service and communication with the architect, we let that design go.

Since then, we've chosen a different architect and feel they've done the best job they could with our NW facing block - I've added a red N on the floor plans to indicate North.

We have a 560m2 block in Western Sydney with a 19m frontage that tapers to 12 at the back.

Would love to get feedback on the orientation and layout of the home.

now i see north is actually in the corner
master will be hot, will need some form of aircon
otherwise very good
you could flip the top floor left to right b2 and master
thinking years down the track when children have moved out
have a vacant room in worst corner
would also place both childrens bedrooms closer to bathroom
and a bit more privacy for parents for date night

Hey annadeeCee

Regarding capturing passive energy, what is the goal? Are you aiming for full passive house certification? Or simply a reduction on the air-con bills in the summer?haha

Thanks again for your feedback!

Looks like the front of your block is facing the west? If so, your master bed will be like an oven in the afternoon. You'll have to blast your AC before going to bed in summer. Downstairs seems fine. You probably want to re configure your rooms upstairs. Personally I designed my master bedroom only to have south facing windows. Reason 1: no east sunlight in the morning to wake me up. Reason 2: no west sunlight in the afternoon to bake the room.

Full passive was well and truly out of our price range.

Looking more at reducing our energy bills long term, maximised natural lighting and actually getting a breeze through our living spaces.

Our current home on this site is a collection of renovations completed by the previous owner over 30 years. After 10 years here we've come to realise there is limited insulation, we can feel breezes around our windows then there are the "home jobs" they completed that are revealing themselves 🤣 Plus we're getting brick rot.

Thanks for your feedback.

Will the 1.2m balcony and shutters on the master help reduce the impact of the western sun? This was a design feature to counter that, but if it won't do much then I would reconsider the layout and remove the balcony to save on cost.

I think the angle of the block means it would be South West windows upstairs, so we won't get away from that western sun.

Passive can get pretty pricey!

As a civil energy system engineer, I've worked on a wide range of systems.

To get what you want, it's important to combine the right level of insulation and a good HVAC system.

If you just get lots of insulation and seal the shell so it can't breathe, water vapour builds up and it gets really steamy (like your hand gets sweaty when you wear plastic gloves).

When you have a good HVAC system that automatically changes the air every few hours, you'll have a very comfortable and efficient home.

A combo of SIP panels forming the building envelope & an MVHR system is just right.

If you just get one, you'll miss out on the benefits. They're better together!

Hope this helps

PS - The liveability of the place doesn't change much after 8 stars. Just paperwork for the passive cert.

The shutters seem to only block 1 out 3 sliding door panels according to the elevation drawing. Not sure how helpful that would be. You already live on this land currently right? You can stand outside in your front yard in the afternoon and have a feel of the sunlight. Now it's particularly helpful because it's summer.

As for balcony, it's a personal choice. I did not step out onto balcony for once in my last house. Totally useless for me. If the front of the house is facing a street, I wouldn't feel comfortable standing up there on the balcony. Do you like to say hi to every passing person with their dog?

Like the other post suggested, maybe looking at swapping position with Bed 2? Bed 2 corner is a nicer location for a master bed. That means you will need to redesign all the bathrooms.

Thanks for that advice. Might be worth reaching out to an energy assessor.

The balcony is a contested design element from a cost perspective. The sliding panels are moveable, so could cover the doors appropriately. And the balcony depth should reduce the direct sun in summer - upon further research. But I've just started looking at design options that don't require a balcony.

We have a bedroom with a similar aspect to the proposed master. All the upstairs rooms are equally as hot as each other because of the poor build quality of the current home - so it's not an easy assessment! But I do know the south facing room we currently have gets the best breezes. Not sure hubby is keen to move the master to the back though. Our street view is nicer - there is a reserve at the end. Wish me luck proposing that adjustment!

careful choice of all building materials, external shading, insulation, window size and placement should make the best of the passive solar options but imo the floor plan doesn't make best use of available space and using the same external footprint my suggestions include moving the stairs so that you can sit in the living room and look out at the garden as well as the tv, relocating windows allows for TV and dining room storage, a narrower island makes more comfortable walking spaces, there's an extra door to create an air lock between powder room and kitchen, omit the side porch to avoid crowding the laundry and powder room doors ..the new upstairs now has space for three minor bedrooms plus master, lounge, family bathroom with separate powder room and generous walk in storage

I really appreciate the effort you went to amend the design. My husband loves the reconfigured first floor. We are curious... Did the first floor expand above the alfresco?

very happy that your husband likes the new upstairs and i did not deliberately expand the upstairs: what seems like extra space is just different shaped rooms without the original huge hallway and there are probably options for more/better internal modification that only an on site designer can calculate eg the access to the upstairs storage room depends on downstairs head room for the stairs and that depends on downstairs ceiling heights but whatever you decide there must be better options for upstairs and that depends on better placement of the stairs...i will be very interested to see your final design

If your bedroom faced exactly west, then those vertical external shading screens are the single best investment you could have made in terms of keeping your bedroom cool in summer. When the summer sun is low in the sky in the afternoon, no level of eaves overhang will save you. Once sunlight hits glass, it's already inside your home and heating it up. So, stopping the sun before it reaches the glazing is paramount and those screens will do exactly that.

On the flip side, if it faced exactly north, then those deep eaves of the balcony will be your best friend, because the sun sits high in the sky to the north, so good deep eaves will shade the glazing all day long.

But, given your bedroom essentially faces the north and the west, the combination of the balcony eaves and screens should serve you really well. With that said, it's hard to know exactly how the sun will strike your home. But IMHO, I would keep the balcony and screens combination, and would feel quite confident your bedroom won't overheat. It'll just be a case of working out exactly where to position those screens in the summer to shade your glazing as the sun starts to go down after midday, but that will be simple enough to do once the home is built.