Browse Forums Building A New House 1 May 16, 2020 12:45 pm Hi all, We are looking at purchasing a block with 3m of fall from the front left to the back right — our builder has said that they won’t build on the block as is, but may do after we do excavation / fill ourselves (plus retaining walls). There are also design guidelines for this estate, but nothing called out pertaining to retaining walls etc. Does anyone have an idea of what we would be best to expect in regards to costs of leveling this block (in preparation for a volume builder), and what sort of plan would be best for the leveling? Really appreciate the assistance thank you! Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ Re: 3m of slope from Front Left to Back Right 2May 16, 2020 2:26 pm If you intend to have a house on flat block and without half of the house being underground, you will be ending up with 2.5 m+ retaining wall at the border of your neighbour, not sure if he will like this very much as your house will be much higher than his and shading off his eastern side (if your are building double story, of course). This load will certainly require to be engineered. In addition to spending tens of thousands on the retaining walls, you would not only need a simple cut and fill, but controlled fill with proper layered compaction and compaction testing. This will be expensive and depending on your soil type, you might even end up in replacing some of the soil under your perimeter with roadbase/sandstone or sand instead and arranging proper slope and perimeter drainage or alternatively proceed with a lot of 3 m+ piers in the fill area. Also, this kind of slope is still not perfect for split level home, however, it still may be a better option for you as you might end will lower retaining walls and much less excavation and compaction requirements. Also, blocks with north frontage are worst when it gets to orientation and passive solar gains and energy efficiency overall. I would not be running away from this block, if I were you, unless you have very very strong reasons to build on the block like this (e.g. views to fit very expensive architecturally designed mansion where its cost will be able to compensate higher site costs, e.g. similar to Hollywood Heights houses in LA - site costs can add up to $1M alone but they don't really matter much for houses costing $20M). In your situation, you will be ending up with $75-100K+ on site costs alone with the block like this and in the end of the day, will be getting a volume builder house with the worst desired orientation. The block size is also quite small, you won't be able to build a really big house on the block like this. Re: 3m of slope from Front Left to Back Right 3May 16, 2020 3:51 pm Thank you Alexp79! For what we were imagining, I was thinking more something along the lines of the “level” being around the 99.9m elevation — that is, at the front left corner of the block, we we would then batter and have retaining walls up to 1.2m here at the highest, going down towards the driveway on the right, and also going down in the other direction (south) along the length of half of the block (decreasing in height). Ideally, our house footprint would go to about halfway up the alfresco of the house to our right, so would need about 1.2m of fill at the extremity here, and then batter off after the rest of the way to the rear. The house on our right would, at the extremity, have only around a 1.2m retaining wall at the highest point, wouldn’t they? As we would only really cover 1.9m of slope with our double storey build envelope, plus giving space to the sides, we would really only need to level over 2.4m of the block, so would have hoped to do around a 1.2m cut at the highest point, and 1.2m of fill at the lowest, if that makes sense. I am very unfamiliar with all this, so I could be seriously missing something — but just trying to get my head around the concepts Really appreciate it though Alex! Re: 3m of slope from Front Left to Back Right 4May 16, 2020 4:53 pm If you house will be having similar setback and similar dimensions to the house on the right, eg: Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ Your lower left corner will be at 101 m, lower right corner - at around 99.9 m, however, you would need a path at the right, so your 101 level will go all the way to 99.8-99.7 line, so you would need to fill and retain up to 1.3 m at the front - this is not a lot, but clay fill over 300 mm would still have to be controlled and over 400 mm it has to be engineered. Your upper left corner will be at 99.5 m, so 0 to 1.5 m retaining wall to your left neighbour and respective 1.5 m of fill over the left side. The worst slope will be at the upper right corner, though, from 101 m to around 98.7 m, so 2.3 m both left to right and front to back. But if you go with 1.5 m split level house, though, you may might be a bit better off with less fill, the majority of which will still be controlled, though. You won't be able to go much lower than street level due to drainage and street level to garage slope restrictions and I really do not see much sense in positioning your home lower than street level - you might be easily ending up with a lot of drainage/flooding related problems. Even if you do a small cut to 100.5-100.25 levels, you won't significantly change much. Hope it helps. Just my 2 cents. Re: 3m of slope from Front Left to Back Right 5May 16, 2020 5:00 pm Probably consider checking builders who have nice split home designs or even houses with pier and beam foundations could be a nice option for you, especially the later as they don't require much of earthworks at all. you need a fridgie to answer but I would think you vac the whole system then add gas if you have a leak, unless it is new install with the gas already loaded, in that case… 1 3639 Old Home Restoration / Renovation Hi, just discovered all these junks left behind under the floor. Could any of these be asbestos? Best to leave as it is or clean up? Thank you for your thoughts 0 8049 A survey must’ve completed by a certified surveyor. This form part of every DA requirement 3 223465 |