Browse Forums Renovation + Home Improvement 1 Oct 26, 2016 7:23 pm Hi all, New to the forum and wanted to get some opinions from the learned about a complex issue. We are in the late stages of design phase of a major renovation/extension. We're on a small block ~ 32mx10m with a heritage listed semidetached 2 story home. The original building can not be altered but we're planning on extending to the rear of the property. Access to the rear of the property is to the side of the heritage house and is 3 m wide. We're planning a reworking of the entire innards of the original heritage building (including moving staircase) and extending beyond the rear of the building (ground and 1st floor) by approx 7 m. We would dearly love a basement (for wine cellar/larder and storage) to be located under the new building and figured the time is now or never for the basement. I've been told by multiple people (architect, engineer, and geotech engineer) that it will be 'difficult' and 'costly' although no one can give me a ballpark figure until 'more exploratory' work is required (i.e. further drilling). We already have a geotech evaluation down to 7.5 m performed specifically with the basement in mind. In short it looks like the water table is at 3.3 m (saturation) and we're on poorly to moderately compacted sand filling (this was assumed even before the formal report). The engineer and geotech have now advised we need to dig deeper and assess more extensively despite knowing the original intention of the original assessment in the first place was to incorporate a cellar. I'm willing to spend up to $10,000 /sqm of basement (up to $150,000) and was wondering if anyone knew if this is in the ballpark of what can be achieved? I understand that it will require pilling/underpinning/dewatering etc but have no idea on how much all of this will cost. If the cost is much more than what I'm willing to spend then I will pull the plug at this stage and save the money for other purposes but if I'm in the ballpark then I want to proceed. All I'm getting at the moment is 'costly' and 'expensive' with no idea if this means 10s thousands, 100s thousands or millions. Reading between the lines I may have to spend thousands of dollars more (if not 10's thousands) for further assessment/design/and independent costings. Having already spent close to $4000 for assessments and design already for the basement I have arrived at nothing/zilch/zip. More money spent on assessment and designing this would eat into the funds set aside for this project. I know this may be a bit complex but any help/information would be greatly appreciated. Re: Basement renovation costs 2Nov 01, 2016 8:00 am Hi Expell You were better going straight to a specialist design engineer/contractor in the first instance Its sounds like they are indicating you will need piling for soil retention and the further piling for foundation support? Your basement doesn't have to be completely submerged this will save heaps on dewatering, piling,etc? Details here https://plus.google.com/u/1/explore/BasementAEC Designer,Engineer (Civil,Const & Envir),Builder,Concrete & Masonry Contract.Struct Repairs Re: Basement renovation costs 3Nov 01, 2016 6:33 pm You've done the right thing getting your geotech and civil engineers involved early to get independent professional design advice, but if you want cost advice then you're probably going to get a more accurate figure from an experienced contractor. As frustrating as it is, anything to do with works in the ground are always a bit of a guessing game. The more you spend on getting more granular geotech information, the more certainty you'll get in costings. If there is a high degree of uncertainty with ground conditions then any contractors pricing the job will either factor in the risk and price it very high, or will price it low to win the job but with a list of exclusions and conditions as long as your arm, and then drown you in variations later. Building Services Engineer Renovating our 1960's modernist home in Brisbane https://forum.homeone.com.au/viewtopic.php?f=53&t=82091 DIY, Home Maintenance & Repair to do it properly you need to dig out the garden and waterproof the outside of the wall. There are some products you can put on the face of the bricks but the water is… 2 4624 Hello Josh, This is Irving from PRIMA, we are a manufacturer of the staircase, railings, kitchen cabinets, windows, doors from China. If you have requirement to purchase… 0 5457 Coming back to your old stomping grounds, huh? Renovations on a budget can be quite the journey. It's like giving your house a new lease on life. The twist of not knowing… 1 3477 |