Context is important, such as who will be living there and what is the climate.

Are you trying to decide between two shortlisted choices?

If budget allows, a custom design to intelligently utilise the orientation would be best.

The first doesn’t have a shower downstairs for guests and the upstairs toilet needs a basin.

The second is a bit weird in that the main bedroom doesn’t have its own ensuite. If I’m buying/building a new home I expect an ensuite that isn’t shared.

The first leaves you some backyard and has a decent outdoor area.

Both choices are being built in Perth. Just want feedback for each build. Mother and daughter and husband living side by side.

After a closer look here are my preliminary thoughts.

House 1

West facing windows in stairwell and rumpus need thought to avoid excess heat gain. I'd almost say remove them but stairwell benefits from a natural source of light and rumpus would be rather gloomy with only south facing glazing opening onto a balcony. WIR and WIL are 'luxe' as they say, but not often a good use of floorspace, and additionally the bathroom seems out of proportion by comparison. A three-way bathroom or a bathroom and proper powder room is better.

The alfresco blocks the most valuable orientation. If the other house has a standard double garage, what is the purpose of the oversize garage in this plan? There is no shower downstairs for the guest room, and as there is a study as well I assume the guest room is intended to be a bedroom? The entry is narrow, which seems like it should be avoidable when the block is actually wider at the front.

House 2

The alfresco blocks the most valuable orientation. The ensuite isn't connected to the master bedroom, is that an error? The narrow garden outside will be a challenge to landscape to provide a nice outlook for the master bedroom. The whole plan feels disjointed. There's a long tunnel from front door to living areas. Main bathroom is upstairs but one of the secondary bedrooms is downstairs. The other house has four bedrooms and a study potentially a fifth bedroom. This house has three bedrooms with potential for additional bedrooms. Which confuses me as to what the question is about, the two choices would not ideally suit the same people.

Side by side meaning in this house to be built, or side by side this is to be added as a dual occupancy, or something else?

You'll get lots of useful advice here but you really need to make clearer what it is we're supposed to be advising about.

I can only reiterate, the two houses don't even look like they'd suit the same people.

House 1  4x2 , slightly bigger block 3 bay garage  No bedrooms to be at the front of the property (mindful that major road is close by, want to avoid the noise.  Could look at a small study for the front room?)  Open plan living.   Love entertaining so want a spacious/open living area that goes out to the alfresco  Kitchen to include butlers pantry  & island bench in centre with no sink / oven would like a clear open area Laundry - I have seen a lot of designs that have this area off the kitchen. I would like to avoid this and have the laundry stand alone, not have to walk through the cooking area.  x1 bedroom to be on the ground floor, will be a guest room. Remaining bedrooms including master to be upstairs  Powder room/shower of ground floor for guest Is a small balcony achievable upstairs (not set on this) Small living area upstairs Lots of storage 

House 2 single grandmother -   3x2    ($300k ) Open plan living (kitchen , dining , lounge) Butlers pantry in kitchen area Theatre room down stairs  x2 bedrooms to be downstairs  upstairs to be x1 bedroom , bathroom (incl bath) and small living (the intent of this area is when sibling/ grandkids come and stay they will be in this area, she wants her room to be downstairs) Wood fire place in living area  Lots of storage

Sorry to be unclear. Seeking feedback relating to proposed designs. Open to suggestions

Thank you @mj. These are two individual homes side by side for 2 seperate families. Mother in 3x2, daughter and family in 4x2

They are not very good designs, especially the second one. I didn't want to say that upfront until I understood better what the individual requirements are. For example the unconnected ensuite was puzzling. If it's for an older family member it needs to be larger for comfort and to allow for future possible mobility needs. Storage is very important and often not adequately provided for even in large houses but be aware walk in cupboards give the impression of providing more storage without necessarily doing so, more wow factor in a display home and more square metres and profit for the builder but not always substantially more usefulness for the occupants. Wood fireplaces are a bad idea except perhaps in some specific circumstances and they don't seem applicable to Perth apart from questionable ambience but at least you might have sea breezes rather than cold air inversions to compensate. I can't even. I'm sure you could do better but that takes being interested enough to want a clever future-proofed house not just what volume builders are 'selling' as des res's. They are uninspiring McMansions which are not taking advantage of modern understanding of what makes good sustainable architecture.

Are they separate blocks or one subdivided block? This is an awesome example of clever multi-household living in Perth. Josh Byrne - Josh's House

House on the left hand block. Upstairs- put basin into WC, Downstairs- alfresco, do not install solid roof. Put in some type of shade that can be retracted to let winter sun in. Eg: Vergola. Or pergola with vines. Garage: why the third garage? The third garage space is compromising internal and external space, which could be used for living and garden. guest bedroom 4 needs a shower in the powder room.

Right hand side home: upstairs, put basin into WC. Downstairs - needs separate powder room. You Only have one toilet and that is in a shared bathroom. If someone is showering, then toilet can not be used by a stranger. Alfresco - do not install a solid roof, have some form of retractable coverage. Kitchen - put a window/s on east wall for the morning sun.

The balcony on left hand home is a waste of good internal space. You will not be sitting out there if there is no view and is noisy from major road near by.

Thank you to everyone for your valued advice. We will revisit these plans most definitely.

I think you are trying to put too many rooms into blocks which are not that big.

A downstairs bedroom must be served by a bathroom not just a toilet.
Toilets by themselves must have a basin.
Toilets need some where to stand when you close the door. There is plenty of wasted space to address these issues. Choice of general layout is your preference, giving consideration to slope of block, view, neighbours, your lifestyle

unable to read dimensions so my suggestions based on estimated room sizes for house one

This is brilliant @okl

would prefer to be accurate but ask your designer to make sure it all fits ok and itm i will have a look at the other house but rereading your information about the noisy road i can't see how the balcony would be used so i would omit the balcony in favour of more space in the activity room

some ideas for mum's house with some light from east and west instead of the dark winding hallway

@okl have taken your ideas on board. What an amazing supportive community it is here. Is everyone here architect's and designers that like to help people?

Thank you for examining our plans

mostly lots of interested people who like to share hard won lessons ...good luck with your plans

"hard won lessons"

Yes.