Using main contractor to plate. Will it save much money?

[flanagaj]

Not wanting to get ahead of myself, but I am struggling to contain my excitement as after 20 years of wanting to do a self build the planets look like they may have at last aligned.  Our house sale has been agreed and is going through and our offer on a building plot has been accepted.  So fingers crossed.

 

Having been a cabinet maker in a previous life and refurbished numerous properties I am planning on doing most of the finishing work myself, second fix carpentry, bathrooms (inc plumbing) and the kitchen.  I also have a brother who is a roofer and I know an electrician and carpenter for the roof.   

 

So as to get things moving quickly I was planning on using a single building contractor for groundworks and taking the structure up to plate height before then taking over and managing the remainder of the project.   If I go down this route can I save quite a bit of money or would you need to project manage every stage yourself to save the most money?

I also want to understand whether I would need an architect to manage the builder up until this stage?

 

Thanks

[joe90]

I paid a local contractor to do the “hard” work, and as a retired (small time) builder did all the windows, plumbing, tiling, kitchen, bathrooms etc like you plan and it worked well. Not sure why you need an architect to oversee the builder? As long as the drawings are correct, your builder understands exactly what you require and your able to keep an eye on him and his work then why?. I was lucky, my builder was brilliant and his team very good, but as the design was mine I kept an eagle on what was done. Regular site meetings are good for both sides in case questions arise. Go for it ?

[flanagaj]

1 hour ago, joe90 said:

I paid a local contractor to do the “hard” work, and as a retired (small time) builder did all the windows, plumbing, tiling, kitchen, bathrooms etc like you plan and it worked well. Not sure why you need an architect to oversee the builder? As long as the drawings are correct, your builder understands exactly what you require and your able to keep an eye on him and his work then why?. I was lucky, my builder was brilliant and his team very good, but as the design was mine I kept an eagle on what was done. Regular site meetings are good for both sides in case questions arise. Go for it ?

Sounds as though you did exactly as I would be planning.  Good point regarding the architect.  My main motivation was just to ensure the smooth running of everything up to plate height.   I don't really understand of have the inclination to be dealing with groundwork related issues ... and was hoping that by using an architect it's a crucial part that I could sort of forget about.   That decision does however depend on how much it adds to the cost if I used an architect to manage that aspect of the build.

I suppose using a single building contractor for the whole stage, does help simplify things considerably.

[Gus Potter]

Hello flanagai.

 

It may be that an SE say or an Architect that has a good SE background is best placed to help here. At some point some calculations may be required for BC purposes if you encounter the unexpected. If you think about it this way. You'll be doing the rest from underbuilding up. The groundworks could be considered as a stand alone package. You are already "project managing" it.

 

You can do a lot to help yourself and keep the cost down. Let's say you engage a local contractor to lay the founds and take the underbuilding up to wall plate level. To price this they will take your drawings, work out the amount of dig and muck away, the volume of concrete, amount of say blocks, wall ties and the amount of say lean mix cavity fill you need. Somewhere they often say.. "based on the drawings"

 

Now for the self builder one problem that arises is if you need to make the founds deeper, say you hit a soft spot. In some case the founds need to be shallow if you encounter rock. Let's take the deeper as more common. Here you have many options; use say trench fill, just make the founds thicker using higher grade concrete if not that much, lay the foundations deeper and make the under building higher. However, there comes a point where your masonry wall thickness needs to be increased if it gets too deep, this is partly to do with the soil pressure on the side of the walls under the ground. All of a sudden things can grow arms and legs.

 

Here an SE type person is often best placed to advise on the most economic option.

 

What you can do is ask the contractor to give you a price based on the drawings but also give you rates for say extra dig, cost per square metre of each masonry leaf. Break this down into a cost say for up to 900mm below working site ground level and up to 1500mm below ground level. Also ask for rates to support the ground if you need to go deeper. Basically ask for rates for extra work. Now, if it turns out once you have excavated the ground that you need to do more work then you have a set of agreed rates. This can transfer more risk to you but you have more control. On the other hand you can just say to the contractor.. you take all the risk.. but you will pay for this.. very rarely will the contractor be the looser here.

 

This is where an SE can really help. Get them in early and they will help you identify what rates you need to get in terms of extra work. Once you have set this up you should often be able to measure up your self and agree the payments.

 

Now let's say you do need to do extra work. The SE will have a discussion with you and the builder and say here is the most economic way of overcoming the unforseen. In summary doing it this way will result in you paying for what you get.. often no more and if you all get on ok and you pay your bills on time you may get a bit extra for free as you'll know.

 

For all, many contractors like working for good reasonable and fair clients so will occasionally go a bit less heavy on the invoicing.

 

 

 

 

[joe90]

I agree that in ground works can be a bit difficult to judge but if you get several test pits dug where the founds are going your BC should be able to tell you depth and width required. A good contractor should be able to price everything else from the drawings and it will be BC that tells you from the drawings if SE calculations are required. 

[flanagaj]

Thanks for the replies.   Given there is a house next door that was recently built, will BC not be able to provide a very good indication as to what depth and width the footing need to be or can the makeup of the ground be very different from one plot to another?

[PeterW]

10 minutes ago, flanagaj said:

Thanks for the replies.   Given there is a house next door that was recently built, will BC not be able to provide a very good indication as to what depth and width the footing need to be or can the makeup of the ground be very different from one plot to another?

BC isn’t contracted to provide that to you unless you pay them - do you know if it’s LABC or private BC..?

 

As @joe90 says, a decent contractor can give you an indication in an hour or two - get a couple of trial pits dug and it will be £150 well spent. 

[flanagaj]

3 minutes ago, PeterW said:

BC isn’t contracted to provide that to you unless you pay them - do you know if it’s LABC or private BC..?

Good question.  Sorry, but I just assumed BC was local area.  
 

 

3 minutes ago, PeterW said:

As @joe90 says, a decent contractor can give you an indication in an hour or two - get a couple of trial pits dug and it will be £150 well spent. 

For £150 that is definitely worth doing.

[joe90]

1 hour ago, PeterW said:

BC isn’t contracted to provide that to you unless you pay them

perhaps I was lucky with my BC (he was very helpful tho ), best to ask if they will give a judgement.

[patp]

A good groundworker should know what he is doing. Just check that he is what he says he is and then use the BC officer to make sure standards are what they should be. Our, very experienced groundworker would have cut corners that the BC officer would not allow.

[PeterW]

1 hour ago, joe90 said:

perhaps I was lucky with my BC (he was very helpful tho ), best to ask if they will give a judgement.

 Meant tell you what the neighbours had done ….