Cost Of Footings For Extension

king132

Hi all,

Another extension question so apologies. I'm looking at options of either getting a builder in to do everything or trying to project manage some of it myself. Trying to figure out how much each part of the project might cost in order to work out how competitive the quotes I have had so far vs the self managing route.

Having two storey extension and would be grateful to find out a rough cost of footings for my project.

Floor area is 7.3mm by 5.3m (39sqm). Been told by BC that footings of 1m deep by 0.6m wide should be sufficient.

A manhole needs to be moved about 8m to outside the footprint of the extension. I estimate around 11m3 of c25 concrete would be enough to deep fill the trench.


One man and his digger, a few labourers. A grab truck. Some bits and pieces to move the manhole and reconnect to the ST sewer.

I've attached a picture but can anyone give me a rough idea of what i should be looking to pay for my footings?

Thanks

king132

https://1drv.ms/u/s!Ah_Qlk1BiInWggzXSGpPJTCc8v-a

Furts

Groundworks, drainage, foundations and such like are all skilled and specialised work. Are you competent to be doing this? If you are then you have no need to ask your question to the forum - you will know the answer.

king132

Furts wrote: »

Groundworks, drainage, foundations and such like are all skilled and specialised work. Are you competent to be doing this? If you are then you have no need to ask your question to the forum - you will know the answer.

No. Sorry for any misunderstanding. Not planning on doing any of these works myself but I'd just like to know how much i should be paying for this type of job.

All the builders quotes ive had, is for the whole shell job. Im just trying to break the project down and figuring out what each stage is likely to cost

Furts

king132 wrote: »

No. Sorry for any misunderstanding. Not planning on doing any of these works myself but I'd just like to know how much i should be paying for this type of job.

All the builders quotes ive had, is for the whole shell job. Im just trying to break the project down and figuring out what each stage is likely to cost

But why? if you are not competent to get involved then it is a pointless excercise. Even your terminology is alarming "one man and his digger, a few labourers, a grab truck" All this sends out a dreadful message. Nobody who is professional and competent is going to get involved on this basis unless you throw money at the job. Which defeats the point really, so just get the work done.

You are assuming your work will be satisfactory, you are assuming others will be prepared to work off what you have done, you are ignoring interfaces and potential liabilities.

All round your approach is pursuing a recipe for disaster here!

Doozergirl

"One man and his digger, a few labourers. A grab truck. Some bits and pieces to move the manhole and reconnect to the ST sewer."


Oh wow. There's the hopeless enthusiasm of the uninitiated if ever I saw it. There's nothing untrue in that simple sentence but sounds like fun.

You've estimated for the filling of a perfectly true trench on perfectly level ground for starters. Even if it all runs perfectly, the trench will be more because they aren't laser cutting and measuring the concrete fill of the trench for you. You'll also lose some of it on the way to the trench, or you pay for the pump.

I recently managed an extension of 2.8 by 5.5m, under duress, for a very lovely lady. It cost me £10,000 to get out of the ground. Thankfully I'd provided an estimate because I expected some issues but wasn't anticipating it all to be made-up ground or finding a well directly over one corner of the building as well as having to deal with half the clay pipes in Worcestershire running through it. Thankfully, my contingency budgeting skills have improved over the years and I did manage to pull the whole thing in under budget, but your description reads like heaven to me rather than the visible option presented to me of creating a swimming pool instead of an extension at one point.

You can guess at how you think something is going to go, but the reality can be far different.

Where are you going to pull this team in from? If you do find them, they won't quote on every eventuality, they can only quote on striaghtforward strip footings or offer a day rate. Find out the day rate and then budget for two weeks for the lot of them and a structural engineer's consultation, just in case.

Your pretty picture of the manhole that needs moving (and drains redirecting) doesn't help anyone who knows what they are talking about. It looks like the poo is going to get there by magic. Where is the actual drain run?

Furts

king132 wrote: »

No. Sorry for any misunderstanding. Not planning on doing any of these works myself but I'd just like to know how much i should be paying for this type of job.

All the builders quotes ive had, is for the whole shell job. Im just trying to break the project down and figuring out what each stage is likely to cost

Your opening post said you wanted to Project Manage, this post has confirmed your intentions, and both Doozergirl and I do not sense that you have competence. You have to ask yourself serious questions here. Your proposals are illegal, and here you only have to look at the ethos of the CDM regulations. You may say fine you are happy to act and take the risks that go with this - countless people do. But those in the industry who try to follow the ethos of the regulations are not going to be available to help you with your role as self appointed Project Manager and Groundworker!