Self Build - Groundwork - 1st step

[idilkachore]

Hi

 

I'm an inexperienced self-builder and I'm just in the process to start building by sub-contracting. I have full planning permission and council building control have given me the go ahead to commence building.

 

I'm in the process of agreeing terms with a groundwork sub-contractor. Basically, he'll do all ground works and handover the site ready for foundation blocks.

 

This sub-contractor has instructed a site engineer. The site engineer has stated the following info is missing from the plans. Therefore, the sub-contractor will not commence groundwork until he gets this info:  

* Finished ground floor levels missing (even though there are existing and proposed levels on the plan)

* Topo survey info about existing site missing

* Control station info missing (position and levels) (what's control station?)

* Positional setting out dimensions/co-ordinates of plot corners missing

* Drainage manhole positions (my inexperienced eyes see drainage info on the plans)

* Drainage invert and cover levels missing

* Plot foundation sizes and levels missing

* Internal pop up pipe positions missing

* Internal water pipe entry position missing

 

Planning department has approved full planning application without all this info, seriously?

I don't want to go back to my architect because it will delay my project by about a year (yes, he's that slow, really).

 

Any suggestions or comments how I approach this first step.

 

Thanks

 

 

 

 

 

[Adam2]

Wow sounds painful - how has your relationship been with them been before this?

 

Maybe you need someone on-site to do a few hours of setting out to get most of that list covered. Control station - as far as I know is a fixed reference point that all house positions are based on. My architect was responsible for water pipes from house entry to point of use etc and the structural engineer co for everything outside - can be painful when they need to talk to each other though.

 

[Temp]

1 hour ago, idilkachore said:

I'm an inexperienced self-builder and I'm just in the process to start building by sub-contracting. I have full planning permission and council building control have given me the go ahead to commence building.

 

and you have definitely got all your CIL paperwork sorted (pre-commencement conditions discharged,  CIL exemption claim form 7, Notice of commencement date Form 6 etc)?  Get any of that wrong and you loose the CIL exemption if you start work.

 

1 hour ago, idilkachore said:

Planning department has approved full planning application without all this info, seriously?

 

A fair bit of the missing data is more to do with Planning than Building Regs (eg the position of the house on the site and dimensions of the house are Planning issues not Building Regs issues).  Unfortunately its up to you (the builder) to ensure the house is in the right place. There is also a difference between Building Regs drawings (which are to show how your house complies with Building Regulations) and Construction Drawings (which tell a builder how to build it).

 

1 hour ago, idilkachore said:

* Topo survey info about existing site missing

* Control station info missing (position and levels) (what's control station?)

* Positional setting out dimensions/co-ordinates of plot corners missing

* Drainage manhole positions (my inexperienced eyes see drainage info on the plans)

* Plot foundation sizes and levels missing

* Internal pop up pipe positions missing

* Internal water pipe entry position missing

 

The above subset would be on a setting out or foundation plan. Typically you would start by getting a site survey done. This would be like a site plan with height data points on a 10m grid.  Someone (you, your architect, or SE) would then add details of your house and founds to it together with two or more reference points (Control Stations). These reference points should be marked on the site by hammering in two posts that remain for the duration of the build (you can also set them out before the site survey and ask them to be shown on it). They should be somewhere out of the way such as in diagonally opposite corners of the plot, ideally on or near a height marker points. The posts should have height reference datum lines on them. They serve as reference points for the people setting out the house in the correct position on the site.  Get these wrong and you end up building the house in wrong spot. The drawing should be  dimensioned from the reference posts so the location of everything on the list can be read off and marked out on site.

 

1 hour ago, idilkachore said:

* Drainage invert and cover levels missing

 

Drainage invert levels tell the ground workers how deep to set manholes, rest bends and the pipes between them. I can't remember if these are normally referenced to FFL or a site datum height.

 

1 hour ago, idilkachore said:

* Finished ground floor levels missing (even though there are existing and proposed levels on the plan)

* Plot foundation sizes and levels missing

 

They probably need a cross sectional drawing of the foundations. This (these) will show:

 

a) Foundation depth and thickness. They need to know how many courses of brick/block below FFL/DPC there will be. That way they know how much concrete to put in the trenches. Too much and you can't fit a whole number of brick courses between the top of the concrete and the desired height of the FFL/DPC. There are standard combinations for cavity walls but I'd have to look it up. Its something like two courses of blocks on the inner leaf are same height as 6 courses of bricks on the outer leaf.  

 

b) the width and minimum depth of the foundation trenches. The width may depend on the load bearing properties of the soil. This is usually determined by an SE who may need you to commission a soil condition report first (sometimes combined with a soil percolation test for soakaways). The depth of the founds may also depend on the soil type and proximity to trees and species.

 

On some types of clay you need the sides of the foundation trenches lined with compressible boards before pouring concrete.

 

How much of all this you actually need can depend on the project, site and soil type.

Edited March 10, 2020 by Temp

[Russell griffiths]

A couple of hours with a site surveying team should have all that sorted. 

Have you had a topo done ?

if so talk to a surveying company, and send it all over to them you should have all this info on your drawings. 

 

It it just sounds like they want it transferred to site so they are not responsible for putting your house in the wrong position. 

[idilkachore]

Thank you all. I really appreciate your assistance.

 

@Adam2 Professional relationship with all is good.

 

@Temp - Thanks for detailed explanation,  I really appreciate it.

CIL paperwork is sorted and I have spoken with building regs officer and he said we're good to go.

 

I have approached my architect as well a couple of other surveying companies for a quote for the missing items in my first post.

I have not instructed anyone yet for foundation plan or site survey. Hopefully, the above requested would include these. All these plans seem expensive, what kind of price should I be expecting?

 

Would foundation plan and/or site survey provide all of the missing information, as listed in my original post?

 

The land previously had houses built on it that were demolished by local council many many years ago. Do I need a topo survey? The land is all most level. Do I still need a topo survey?

 

@Russel - the plans - snippet of which is attached, does show some drainage and existing and proposed levels. However, I'm not if this is the complete info.

 

Thanks again to all for assistance

 

 

 

 

 

[Temp]

For the drainage stuff you may need to lift manholes in the road to find out how deep the sewers are. Then make a drawing working back to your house accounting for the fall in each length of pipe to calculate the invert level for each inspection chamber.

 

For example if the sewer connection was 2m below reference level and the nearest IC on your plot was 40m away the bottom of the IC would be calculated as..

 

1:80 fall over 40m = 0.5m so the IC would be set at 2m - 0.5m = 1.5m below reference (Thats not necessarily 1.5m below ground because the ground may slope).

 

Repeat for each IC untill you get to the bottom of the stack.

 

[idilkachore]

Thanks Temp.

 

I have been in contact with sub-contractors site engineer and says:

In your case though, with it being a single new build plot, all that [name removed] would require to start the foundations would be a distance from the back of the existing footpath to the front of the plot and a distance from one of the side boundary’s. The plots finished ground floor level I assume would be a certain distance either above or below the back of the existing footpath.

The architect usually provides this information on a setting out drawing.

 

All is required is couple of measurements on a drawing to cover their back as you guys have said. I didn't get a setting out drawing from my architect so I have requested it. I think there would be a charge. However, my main concern is slow speed of my architect. When will I get the setting out drawings is any bodies guess (even if we agree dates, he don't give s***).

 

I think this sub-contractor wants to do things by the book, others have said they can start marking out and start foundations within a day.

 

From their original requirements I really was stressed.

 

Will see what the architect replies back with.

 

Thanks again guys.

 

 

Edited March 12, 2020 by idilkachore

[idilkachore]

Hi 

 

The architect has come back to me and says:

 

Usually on the job of this scale we provide a full service to the client and provide full detail plans and a level of site visits to make sure the job is progressing adequately. This level of service though does involve a fee of around the £3k mark to provide an adequate service.

 

£3k is a lot of money. I think it's a rip off. I feel I've had enough with this architect. However, my concern is what happens if I go with another architect at this stage? Is that possible? Would it be a wise move to go with another architect?

 

Do I definitely need the setting out drawings or can I get a surveyor to do the markings?

 

All I need are setting out drawings to get the ball rolling. 

 

Thanks

 

Edited March 12, 2020 by idilkachore

[Jilly]

I've changed architects as I thought my first one seemed inattentive to detail, but changing has caused all kinds of bother, as I, like you, have been unaware of what I need to ask for. Most people say you need to allow about £20k for fees in total, which yes, does seem extortionate! if I do this again I would probably chose a kit house for transparency.

 

[idilkachore]

Thanks Jilly.

I've not budgeted 20k for fees, which do seem high but then again I don't know what fees/work is included in 20k.

 

 

 

 

[idilkachore]

I've received an email from sub-contractor's site engineer and he says:

You need the dimensions and levels highlighted on the attached architects drawing. The fact that they have drawn a line and made a note about "proposed levels" suggests they have that information just not put it on the drawing.

 

I was under the assumption that I needed completely new plans drawn with the dimensions and levels and was willing to pay for it. However, from above it appears the architect has forgotten (give him benefit of doubt) to add the dimensions and levels to the existing drawings. But he's asking me to pay £3k for already drawn plans and dimensions and levels which he already has.

 

Any comments/suggestions would be appreciated.

 

[Russell griffiths]

You should have a SITE LAYOUT EXISTING. you should have. SITE LAYOUT PROPOSED. 

both of these would be needed for planning consent, you could not get planning without having the proposed site plan, so in effect you already have everything. 

It just either needs dimensions putting on it or some form of reference for location

a drawing is not good enough to measure off.

your architect will have all this information digitally, it will take him 2 minutes to add dimensions and forward it on to your contractor. 

Get on the phone and give him a big earful. 

He should have all your site plans in layers so he can add and remove layers depending on what you need to view. 

[idilkachore]

Thanks Russell 

 

Both existing and proposed levels are on the plan copies I have.

 

I know my architect has everything, he's just being difficult.

 

I have emailed him two days ago for updated plans in pdf format or CAD drawings and I'm still waiting a reply.

 

I don't understand, the site engineer says, if I get CAD drawings from the architect he will be able to add the the required dimensions on the drawings. He will then pass the updated drawing to ground worker who can then make a start.

Why does he need the drawings? Why not just pass the dimensions to the ground worker on any piece of paper or even better write on the plans with a pen?

 

 

 

[Russell griffiths]

48 minutes ago, idilkachore said:

Thanks Russell 

 

Both existing and proposed levels are on the plan copies I have.

 

I know my architect has everything, he's just being difficult.

 

I have emailed him two days ago for updated plans in pdf format or CAD drawings and I'm still waiting a reply.

 

I don't understand, the site engineer says, if I get CAD drawings from the architect he will be able to add the the required dimensions on the drawings. He will then pass the updated drawing to ground worker who can then make a start.

Why does he need the drawings? Why not just pass the dimensions to the ground worker on any piece of paper or even better write on the plans with a pen?

 

 

 

They will have it in electronic format, they then put the data in to their total station (setting out machine) when they get to site the total station has all the measurements stored in it

they stand in one position and shoot the measurements across the site. 

You could do the job and not even get a tape measure out of his tool box. 

 

My house has something like 11 external angles and 8 internal ones, it was all set out on this machine, not one tape measure or set square even on site. 

[idilkachore]

Thanks Russell

 

I have sent 3 emails to my architect and it's been two days now and I'm still waiting for  reply. I have requested either updated drawings in PDF format or CAD drawings.

Hopefully, the good news will come next week.

[Adam2]

Yes I had the same experience with my engineer co. Architect is fine but the SE was a total nightmare - trouble is they know as a private client you're pretty stuck as moving to a new firm is such a barrier and they may be worse!!!!

[idilkachore]

 

I've sent further two emails today requesting (/begging) for the updated drawings. No reply, nothing!

 

 

[idilkachore]

Another email sent today but still no reply.

 

My architect is registered with Chartered Institute of Architectural Technologists (CIAT). Is it worth complaining to CIAT at this stage? Or should I email my architect and say I'm considering complaining to CIAT or considering legal action?

 

Has anyone had any experience of complaining to CIAT or taking a legal action against the architect/structural engineer/etc? Is it worth it?

 

 

 

Edited March 17, 2020 by idilkachore