Topographic survey - mandatory or nice to have

[Internet Know How]

Hey everyone,

 

My architect has recommended one of these surveys. I have already measured the site with a tape measure, so whilst this isnt exactly laser level, could I not just buy a laser level myself for about £50 if he wanted something a little more accurate?

 

(ARCHITECT) Land Surveyor - A topographic land and level survey of the whole site will be required. We envisage the cost will be circa £500 + VAT and we can obtain quoted from surveyors we work with regularly.

 

(ME) Is this needed to support planning?  

 

(ARCHITECT) There is nothing worse than completing a design and discovering that the site is slightly different in size or shape, it can lead to a lot of abortive work.   

 

Thanks

 

Chris

[Mr Punter]

These are useful if the planners (or you) need to see the proposal in context with neighbouring houses.  It also shows levels and features such as utility covers, levels and inverts.  It can help greatly with setting out the building.

 

You probably will not need it for planning, but the planners may ask for information, such as proposed ridge height, in relation to Ordnance Survey benchmarks, which you can get from the topo.

[Internet Know How]

1 minute ago, Mr Punter said:

These are useful if the planners (or you) need to see the proposal in context with neighbouring houses.  It also shows levels and features such as utility covers, levels and inverts.  It can help greatly with setting out the building.

 

You probably will not need it for planning, but the planners may ask for information, such as proposed ridge height, in relation to Ordnance Survey benchmarks, which you can get from the topo.

Ah right I see, so it could be a pre-condition from the council that they want to see more information before approving my application? Obviously I am just trying to save on spend here if not absolutely necessary

[Mr Punter]

If the site is flat, simple to set out, the height of the building will not be critical you could do without.

 

I have bought a site in the past that had planning with no topo.  The proposed house would not fit so we had to resubmit.

[Internet Know How]

1 minute ago, Mr Punter said:

If the site is flat, simple to set out, the height of the building will not be critical you could do without.

 

I have bought a site in the past that had planning with no topo.  The proposed house would not fit so we had to resubmit.

I guess this is what the Architect is trying to avoid....when we start the build the house does not fit. Obviously his preference would be to have to the mm measurements to work from. I think the main consideration for my plot given it is flat, is ensuring the front elevation width and rear elevation widths are perfect.

 

Front: 25meters

Rear: 17 meters

 

As you can tell from the figures, the front to back goes rather like a triangle shaped piece of land. 

[Ferdinand]

I think "mandatory or not" is the wrong question.

 

"Useful or not" is the right question.

 

If you are not on a bowling green, it is a very good basis for everything else.

 

F

[ProDave]

Before I even bought my site, I (with the agreement of the owner) had designed the outline of the house that would fit on it, and marked out the outline of the house on the ground with pegs and marking tape.

 

For detailed planning I surveyed the site myself, measuring heights of important points using a laser level with reference to a temporary bench mark I created on a post.

 

I even planned a landscaping plan marking out finished heights at spot places, using up all the excavated soil from the build to make the site less sloping than it was originally.

 

The most critical thing to work out is the drainage plan as water must run downhill so you need to be sure if say you are having a treatment plant that there is a downhill route from the house to the plant to wherever it will drain to.

 

At no point did I feel any need to pay someone else to do this for me.

[DevilDamo]

What are you proposing... a new dwelling or extensions/alterations to an existing?

[nod]

I’m pretty much with Fave on this 

Unless you are on a really tight site 

You can peg the house out yourself 
In fact myself and my wife were doing exactly that yesterday 

(Prior to purchase )

I set our previous plot out like this 

Like yours it sloped into a triangle 

Wgen I set the foundations for the house the seller halted us as she was convinced the house was to far over 

She brought in a surveyor who checked it out You can hire equipment that is millimeter accurate for  not a lot of money per day 

 

All these savings add up 
 

[the_r_sole]

Depends on the site, I regularly have people who don't want to pay for a topo survey, it just puts more risk on the job.

With a decent topo you can figure out the floor levels and ridge heights etc sometimes required by planning, but it would also let you figure out what type of ground floor would suit, how much cut and fill you need, whether any ground works are required to get correct gradients for paths and parking etc.

All stuff that can be "played by ear" but could also cost you way over £500 if isn't worked out right...

[Conor]

For that sort of job you should be paying more like £250. It's a morning work for a surveyor with GPS unit. They are very useful to have re services. And if there are ever any disputes or queries, you've solid, verifiable measurements to refer to, e.g. of a neighbour says you've built 500mm too far forward, this is a doddle to check. If you've not surveyed it, and it's setout incorrectly, you could be in a world of pain that will cost a lot more than £250.

 

 

[Temp]

7 hours ago, Internet Know How said:

I have already measured the site with a tape measure, so whilst this isnt exactly laser level, could I not just buy a laser level myself for about £50 if he wanted something a little more accurate?

 

You could probably do one yourself.  Here is part of ours. Basically its a site plan with a 10m grid of height markers and two reference points noted at the bottom.  This version was done for the planning application so it also shows our proposed house (mostly off the top of the scan). I assume the surveyor sent an electronic copy to the Architect so yours might be expecting it in some electronic format he can import into his CAD. 

 

PS We had one done because the site slopes.

 

Edited September 5, 2020 by Temp

[Internet Know How]

18 hours ago, DevilDamo said:

What are you proposing... a new dwelling or extensions/alterations to an existing?

new dwelling

[Internet Know How]

19 hours ago, ProDave said:

Before I even bought my site, I (with the agreement of the owner) had designed the outline of the house that would fit on it, and marked out the outline of the house on the ground with pegs and marking tape.

 

For detailed planning I surveyed the site myself, measuring heights of important points using a laser level with reference to a temporary bench mark I created on a post.

 

I even planned a landscaping plan marking out finished heights at spot places, using up all the excavated soil from the build to make the site less sloping than it was originally.

 

The most critical thing to work out is the drainage plan as water must run downhill so you need to be sure if say you are having a treatment plant that there is a downhill route from the house to the plant to wherever it will drain to.

 

At no point did I feel any need to pay someone else to do this for me.

sounds like money well saved if you knew how to do it yourself. I could learn I guess but I am trying to balance out those things I will do to save money and cut off where I just dont have the time. 

[Internet Know How]

15 hours ago, nod said:

I’m pretty much with Fave on this 

Unless you are on a really tight site 

You can peg the house out yourself 
In fact myself and my wife were doing exactly that yesterday 

(Prior to purchase )

I set our previous plot out like this 

Like yours it sloped into a triangle 

Wgen I set the foundations for the house the seller halted us as she was convinced the house was to far over 

She brought in a surveyor who checked it out You can hire equipment that is millimeter accurate for  not a lot of money per day 

 

All these savings add up 
 

The existing house is not yet demolished which is a slight problem, however I can measure neighbour wall to wall with a laser level to get a more accurate view for the architect if needed. When the house has gone, I can get the groundworks guy to mark out with pegs, and then take another measure to align it up with the plans. The new house will sit exactly on the rear elevation boundary but frontal elevation will come foward 2 meters, and then extending the length of the plot width wise leaving a few meters either side for passage around the side of the property.

 

Just seems like it could be a bit overkill to shell out another £700 here

[Internet Know How]

14 hours ago, the_r_sole said:

Depends on the site, I regularly have people who don't want to pay for a topo survey, it just puts more risk on the job.

With a decent topo you can figure out the floor levels and ridge heights etc sometimes required by planning, but it would also let you figure out what type of ground floor would suit, how much cut and fill you need, whether any ground works are required to get correct gradients for paths and parking etc.

All stuff that can be "played by ear" but could also cost you way over £500 if isn't worked out right...

If I am digging out for a basement though, all the gradients would be self made on the way back up. Maybe I will get a quote off someone and if they can do it for like £250 all in then yeah. Otherwise, everyone who comes in with a pen seems to want to add a few zero's on the end. Being in a very nice area people think its the postcode lottery too so quotes go up

[Internet Know How]

13 hours ago, Temp said:

 

You could probably do one yourself.  Here is part of ours. Basically its a site plan with a 10m grid of height markers and two reference points noted at the bottom.  This version was done for the planning application so it also shows our proposed house (mostly off the top of the scan). I assume the surveyor sent an electronic copy to the Architect so yours might be expecting it in some electronic format he can import into his CAD. 

 

PS We had one done because the site slopes.

 

Ok I didnt realise my Architect may import and overlay his design onto it to ensure it fits correctly. Even still, if I laser level out the site wall to wall I cant see how we can go wrong given its fairly level and will be digging out for a basement

[PeterW]

10 minutes ago, Internet Know How said:

Ok I didnt realise my Architect may import and overlay his design onto it to ensure it fits correctly. Even still, if I laser level out the site wall to wall I cant see how we can go wrong given its fairly level and will be digging out for a basement

Ok so a basement adds complexity and you would be better spending the money as you will have a lot of spoil to remove. On an 80sqm basement, each 250mm down would equate to 2 20 tonne lorries of muck away at about £175 a run around here - so get the levels wrong by 500mm and you will have spent £700. 
 

You’ve said elsewhere that this is a big (500sqm..?) build but on a small budget - it is these up front costs that can save you significantly in the long term and it will also influence your budget and even potentially your plans. 

[Internet Know How]

1 minute ago, PeterW said:

Ok so a basement adds complexity and you would be better spending the money as you will have a lot of spoil to remove. On an 80sqm basement, each 250mm down would equate to 2 20 tonne lorries of muck away at about £175 a run around here - so get the levels wrong by 500mm and you will have spent £700. 
 

You’ve said elsewhere that this is a big (500sqm..?) build but on a small budget - it is these up front costs that can save you significantly in the long term and it will also influence your budget and even potentially your plans. 

I have worked out over 200SQM that I could potentially dig out 1000 tonne of sand. A firm I know may take it away for free or maybe just charge me for the haulage element only. I guess you could say its a small budget because if I brought in a main contractor this build would not be feasible. Managing the trades myself, it can be done

[DevilDamo]

For any new build dwelling, I would always insist the client having a topographical survey carried out. It has already been mentioned before, but the survey would help with the drainage and landscaping design. It’s also an important factor in being able to set out the new house with co-ordinates as opposed to distances from adjacent buildings or structures.

 

The survey fee in the overall grand scheme of things isn’t a lot of money to spend, especially the time and money it would save you in the future should something go wrong.

[PeterW]

11 minutes ago, Internet Know How said:

I guess you could say its a small budget because if I brought in a main contractor this build would not be feasible. Managing the trades myself, it can be done

You will be saving the main contractor margin, so at best 5-10%. 
 

12 minutes ago, Internet Know How said:

A firm I know may take it away for free or maybe just charge me for the haulage element only.

1000 tonnes, or 800 cubic metres of sand will need 40-50 wagons. Even at transport cost that would be £4-5k depending on where you are in the UK. 
 

There are some much smaller basements on this forum that have cost £2k/sqm, and those costs don’t scale well - has your architect given you a rough target cost for build ..??

[Ferdinand]

4 hours ago, Internet Know How said:

Ok I didnt realise my Architect may import and overlay his design onto it to ensure it fits correctly. Even still, if I laser level out the site wall to wall I cant see how we can go wrong given its fairly level and will be digging out for a basement

 

The issue I see here is that if you get it wrong, everything else could be off all the way through and that could be costly and on your head. 

[Internet Know How]

1 hour ago, Ferdinand said:

 

The issue I see here is that if you get it wrong, everything else could be off all the way through and that could be costly and on your head. 

Yea right up to height level on the build. I reckon its one of those things thats best to have

[NandM]

What do the numbers mean? I was look at one yesterday and couldn't work out if that was the distance between the points or something else.

[Mr Punter]

On site surveys the numbers with 3 decimals are the height (normally) above ordnance datum (AOD) - which is a recognised benchmark height based on mean sea level.