Second Storey Addition (Perth Metro)

Discussion in 'Renovation & Home Improvement' started by semper_fi, 27th Dec, 2023.

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  1. semper_fi

    semper_fi New Member

    Joined:
    25th Dec, 2023
    Posts:
    4
    Location:
    Perth, WA
    Hi everyone,

    Season's greetings! This is my first post here. We bought a small (130 m2) double-brick house, built in1980, in the Perth Metro area (south of river) about five years ago. We are considering adding a prefabricated master bedroom and an ensuite atop the existing metal-roofed extension to the original floor plan -- please see below:

    [​IMG] .

    I just wanted to tap into the collective wisdom of you folks here to help me gauge the feasibility of what we have in mind, the estimated cost and also any pitfalls we should keep in mind.
    I have a few particular queries and would be most obliged if you could share your wisdom on the following:

    1. Most builders suggest the cost of a second storey addition starts from 250K. Of course the overall cost would depend on the floorspace added and the materials used. However, for the proposed 29 m2 addition above, based on average materials and finish quality, that price tag seems high. Based on 5K per m2, one would expect the cost to be well below 200K. I am looking for a ballpark estimate of the cost to have in mind when I speak to builders.

    2. Is it worth splitting up the design/planning and building (owner builder?) to save on cost?

    3. Should I consider onsite build vs prefab? I can't relocate for the build, so I suspect onsite build is not an option.

    4. Any particular recommended builder I should approach for this project?

    Thanks a lot for reading the long post.

    Cheers
     
  2. wylie

    wylie Moderator Staff Member

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    14,006
    Location:
    Brisbane
    Welcome to the forum. :)

    I can’t help with costs except to say if you are going to do this extension why not add a larger area. It seems shortsighted to add just one room.
     
  3. Mark F

    Mark F Well-Known Member

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    Location:
    Canberra
    When you build up you run into the additional expenses of:
    - lifting building materials - more hours and/or hire of lifting gear
    - scaffolding
    - working at height oh&s requirements
    - cost of stairs
    and on it goes.
     
  4. Westminster

    Westminster Tigress at Tiger Developments Business Member

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    Location:
    Perth
    When you consider the amount of space you'd lose at ground floor for staircase and plumbing ducts and how much more per square metre it costs to go up vs extending at ground floor; I would seriously consider extending into the backyard.

    You do appear to have quite a spacious backyard that could take a master bedroom extension and you probably wouldn't need to move out for the works.

    I'm not up to date on how much upstairs extensions costs but it's generally at least 1.5-2 times as much as going out.

    Get some quotes on doing both if you can spare the backyard.
     
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  5. semper_fi

    semper_fi New Member

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    25th Dec, 2023
    Posts:
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    Location:
    Perth, WA
    Thanks Wylie. Yes; we've thought about that and are not keen on extending our floor space beyond what we are able to keep clean and tidy. Besides, with the green agenda being rolled out ever more aggressively, energy costs are headed one way for the foreseeable future!
     
  6. semper_fi

    semper_fi New Member

    Joined:
    25th Dec, 2023
    Posts:
    4
    Location:
    Perth, WA
    Thanks Mark; good points. To avoid some of the complications above, we're leaning towards a prefab to be craned into position.
     
  7. semper_fi

    semper_fi New Member

    Joined:
    25th Dec, 2023
    Posts:
    4
    Location:
    Perth, WA
    Thanks a lot for the detailed response, Westminster.
    We grow our veggies in the backyard and don't wish to part with the available space and hence the plan extend upward.