Browse Forums General Discussion 1 Jul 17, 2017 10:27 pm I am having a new unit built at the rear of an existing house. The rear area is essentially flat with the front half of the block sloping to the street. The unit was at the frame stage before the builder advised me that the work had commenced and that the slab had been poured. On my first inspection it became obvious that the building was now sitting well below the original ground level. The builder claimed they had merely followed the builders benchmark located by a surveyor and seemed to allude to the levels of the plans not matching the site. Sometime after this I was hit with a substantial variation claim for the extra earthworks to cut the block to the indicated level. I subsequently engaged my own surveyor and found that the FFL of the building is about 200mm below that specified on the plans. The survey also appeared to point to the reason for this. The original plans had the dwelling being built abutting an existing garage with the house FFL to be 150mm above the garage FFL. Due to the deteriorated condition of the garage and its cement slab it was decided to demolish the structure and replace it with a carport, the garage being demolished some weeks before construction on the new unit began. Once the garage was demolished and the slab removed, the immediate area was cleaned up, leveled and left. It appears that the surveyor used this now lower area as the reference for establishing the builders benchmark as the FFL of the new building is 150mm above that level, but close to 200mm below other levels on the site that do conform with the levels shown on the plans. The builders have not been open or honest with me, firstly claiming that the plans must be wrong, and it was their responsibility to blindly follow the benchmark provided by the surveyor. Now that I have the results of my survey and wanting to determine the chain of events that lead to this error, they are trying to brush it off claiming that it may delay the construction. I am extremely unhappy about both the error, and the actions of the builder in trying to keep me out of the loop as well as trying to brush it off. I am going to have a site meeting with the builder so as to determine the chain of events and where the responsibility lays for the problem not being identified and corrected before it was too late, but where do we go from there. There is no doubt that the as built FFL will be deemed defective given the amount it deviates from the plans FFL, but what are the consequences of that, and what is the likely course of action that may be required to follow. I feel like insisting that the building be demolished and rebuilt according to the plans. I would appreciate any informed opinion that will help me get it all into perspective. Thank You Re: FFL 200mm low 3Jul 18, 2017 12:12 pm StructuralBIMGuy @john3294 welcome to the forum The main issue is what effect will the lowering have on your build.and the surroundings Please post photos as it is a common problem. Thanks for your response. I have sent photos to you by PM. I don't know how to post photos to the forum. Re: FFL 200mm low 4Jul 18, 2017 7:27 pm John3294 Look for the three dots in the previous post Always check the FFLs before they commence site works why 1. It changes the costs of siteworks ie Cut & Fill.. if possible aim for a balance point height (optimal) 2.Incorrect levels may lead to additional engineer costs. 3.You could be in breach of planning guidelines 4. It can affect rainwater run-off and stormwater costs 5. Ideally water should run away from your footings 6., 7, 8, etc Designer,Engineer (Civil,Const & Envir),Builder,Concrete & Masonry Contract.Struct Repairs Re: FFL 200mm low 5Jul 18, 2017 8:13 pm StructuralBIMGuy @John3294 Look for the three dots in the previous post Always check the FFLs before they commence site works why 1. It changes the costs of siteworks ie Cut & Fill.. if possible aim for a balance point height (optimal) 2.Incorrect levels may lead to additional engineer costs. 3.You could be in breach of planning guidelines 4. It can affect rainwater run-off and stormwater costs 5. Ideally water should run away from your footings 6., 7, 8, etc I sent you a PM before I found your reply here. If the builders had kept me informed of their schedule I would have certainly wanted to inspect the site before the slab was poured, however they didn't inform me that the construction had began until they were ready to claim the progress payment at which time the frame was virtually complete. If I had had such an opportunity I certainly would have wanted explanations why it was being set so low on the site. It wasn't something that could be easily missed, it was and is blatantly obvious something is not right. Solutions can usually be found for the technical issues, at a cost, but what are the consequences if it breaches planning guidelines? Given how much the FFL deviates from that on the plans, what are the possible ramifications of that. John Re: FFL 200mm low 6Jul 18, 2017 8:43 pm John3294 You have hit on the reason why some don't tell you when they start..they don't want anyone inspecting the work. You have to insist and even then some builders still don't tell you.They ignore Building Inspectors.. not so much structural engineers. Sorry to say the planning height guidelines are very weak to enforce after the event Designer,Engineer (Civil,Const & Envir),Builder,Concrete & Masonry Contract.Struct Repairs Re: FFL 200mm low 7Jul 18, 2017 8:55 pm John3294 Solutions can usually be found for the technical issues, at a cost, ..... A cynical person might also see that as an opportunity to make a lot extra post contract signing (see 2 above in my post) ? you will need to weigh up all the facts. I can't stress how important it is to ask questions, Take photos & always make informed decisions before the event Designer,Engineer (Civil,Const & Envir),Builder,Concrete & Masonry Contract.Struct Repairs I am looking to design an entry door to a lower ground basement that has 2200mm between the external entry height to FFL of the ground floor. This door will provide an… 0 11352 4 6194 If you can calculate the reasonable charged head from let's say 100mm below the gutter to the top of where the vertical riser's horizontal discharge pipe will be, that… 11 17525 |