Foundations estimate

[nikki]

Hi everyone.

 

I'm trying to put together a budget for a self build so we can work out if our dream of building our own house can become a reality!

 

I was wondering if anyone knows how much groundworks would cost for a footprint of approx 1200sqft (110sqm)? I know it depends on a lot of things and you don't really know until you have bought the land, but I just wanted to get a broad range of what to expect for the groundworks side of things, and how much we should budget for it realistically. We would be building in Scotland (probably the Highlands) if that helps.

 

Thanks!

[ToughButterCup]

1 hour ago, nikki said:

[...]

I know it depends on a lot of things and you don't really know until you have bought the land, but 

[...]

 

Thats a but too far I'm afraid. 

Why?

Piles, sand, rock, slope, hidden services to name but several. Globally, £1350 ish per square meter for a complete build should be a very rough guide. Not true in Sandbanks, or Westminster and a little steep for the far North East .

[Jeremy Harris]

Welcome.

 

I'm afraid the range of ground work cost is massive, and very site-dependent, so it's really hard to give even a very rough estimate.

 

Our site was probably near the upper end.  It's small, and cut back into the bottom of a hillside, with no mains water or drainage available, only mains electricity.  We had to dig out around 900 tonnes to level the site, and build a pretty hefty retaining wall.

 

The cost of the basic groundworks, excluding the foundations for the house, or the borehole for the water supply, but including the treatment plant for sewage, came to about £55,000.  The borehole for water cost about £6,000 in the end (bit of a saga).  Electricity connection cost about £3,500.  The house foundations were included in the package we bought, but were probably around £12,000 (for a 130m² 1 1/2 storey build).

[K78]

Impossible to estimate without knowing the ground conditions.

[recoveringbuilder]

Welcome, you’ll never get a true price for your groundwork’s until you have a plot, there is so many variations on ground conditions, we thought our plot was pretty level until the dig out started but luckily we had plenty of land to ‘lose’ the excess soil otherwise it could have cost a lot to have it taken away, then there’s the spec of foundations, probably impossible to get a figure without having the land. I think ours cost around £12k but many on here will have spent a lot more,

[Thedreamer]

2 hours ago, nikki said:

Hi everyone.

 

I'm trying to put together a budget for a self build so we can work out if our dream of building our own house can become a reality!

 

I was wondering if anyone knows how much groundworks would cost for a footprint of approx 1200sqft (110sqm)? I know it depends on a lot of things and you don't really know until you have bought the land, but I just wanted to get a broad range of what to expect for the groundworks side of things, and how much we should budget for it realistically. We would be building in Scotland (probably the Highlands) if that helps.

 

Thanks!

 

If building in the highland, watch out for sites on peaty ground.

 

 

 

[selfbuildaberdeen]

Our QS reckons 14k for 113m2, 200mm deep slab which is on flat ground.

Soil survey and engineers drawings completed already. 

We know there are no services to be dug up and this does not include any drainage of any kind... im hoping hes going to be wrong....

Drainage to treatment plants for both foul and surface is coming in at 22k!

Edited July 26, 2019 by selfbuildaberdeen

[Redoctober]

@nikki take a look at this web link - it might be useful if only to steer you towards further research / reading via the magazine itself. I'm not sure how current the prices mentioned are but it might be a start. This was one of the methods we used when we first set out trying to establish how much things might cost and whether or not  they fitted within our budget. Good luck.

https://www.homebuilding.co.uk/foundations-cost-guide/

 

[nod]

You can be pretty accurate with an estimate prior to starting 

But as pointed out above you will 

Need your plot Or certainly an engineers foundation drawing 

[Jeremy Harris]

12 hours ago, selfbuildaberdeen said:

Drainage to treatment plants for both foul and surface is coming in at 22k!

 

 

Not a good idea to run surface/rain water drainage to a treatment plant, as they are not intended to take large volumes of relatively clean water.  The treatment plant will have to be massively oversized in order to cope with the volume of surface water drainage, and as a consequence it will have way too few nutrients to maintain a viable aerobic bacteria colony.  This means that during dry weather the foul drainage will not be adequately treated and the unit will end up discharging effluent that is well above the permitted limits.

 

Best to ensure that only foul and grey drains lead to the treatment plant and that the surface water and roof run off is dealt with by soakaways, perhaps with some form of attenuation system in order to comply with the SuDs requirements.