How to organise groundworks

Darren Livesey asks:

I have a simple question, I think?

At the groundworks stage of a build, how do people decide where everything is going? I have an overall plot drawing to scale, which was needed for outline planning permission. Is it now up to me to tell the groundworker where to lay the services, drains etc and can he simply just work from my instructions and the overall plot drawing?

What will he need for the foundations - does this come in the form of a building regs drawing? It is all very confusing and seems rather daunting. We also need a pumping station installing as the house is lower than the private foulwater sewer. Who designs this? Can I just tell the groundworker to put it "there" for instance? I think I am getting confused with what the architect requires for submitting to building control and what the groundworker "works" off.


Mark reckons:

A few brave souls decide to build off planning permission drawings, but it's really not to be recommended, esp. if you have never done it before. It would be a bit like setting out to drive from Aberystwyth to Hunstanton with nothing but postcard of Hunstanton pier to guide you. You need a map.

The groundworker will do what you tell him to: he may get it right, he may not. If it's wrong, it will be up to you, not him, to rectify it. What you need is a load more drawings and a few specifications. Normally these form part of a building regs application. In the vernacular of the building trade, "the job needs to be specked up." First the house needs to be detailed so you at least know the dimensions and locations of the walls, and you need to decide which ones will be load bearing. Someone, usually the architect, has to do this work: it's absolutely standard practice. Only then can you proceed to a foundation/floor design, also usually carried out as part of the specking up. The drains and services should also be detailed
with reference to the house layout (where are the bathrooms?) and the site levels. You may find that the drainage suppliers will do this work for you for free, if you supply them with levels and a detailed floor plan.

Then you proceed to the setting out stage where you, in effect, transfer the details from the drawings onto the ground. Then when the groundworker comes to do his stuff, it's all a bit like painting by numbers. He has not so much a map as a paper trail guiding him where to go. It's also much faster, and much less prone to error. Believe me, when the excavators start moving earth around, you really don't want to be guessing where the wall should be or where the pumping station should be going.

>We also need a pumping station installing as the
> house is lower than the private foulwater sewer. Who designs this -
> can I just tell the groundworker to put it "there" for instance?

The position of the pumping station will be partly governed by building regs - Part H covers this in England & Wales - and partly by common sense. There will be a minimum distance you will have to place it from the house (I seem to remember it's 4.5 m min): after that it's up to you and your designer/groundworker. The building inspector will advise.

Don't rush. Remember that every hour spent in preparation saves at least three spent snagging at completion.