New build on flood zone 3

[Jeremy Harris]

5 minutes ago, KimB said:

We are just in flood Zone 3, only have the land!!!! We haven't as yet commissioned a Flood risk assessmentyet. The architect we are using is only returning from holiday today, and has said we are on his priority list. Can we only use EA or can we use an independent company to do the flood assessment do you know?

 

The letter I had from the EA did say that the FRA I needed to do should be "site specific and proportionate" to the level of risk:

 

Quote

Flood Risk
The site falls marginally within Flood Zones 3 (high risk) and 2 (medium risk) as defined within Table D.1 of Planning Policy Statement 25 (PPS25) Development & Flood Risk.  However we acknowledge that the majority of the site and footprint of the proposed dwelling and detached garage fall within the Flood Zone 1 (low risk) portion of the site.  Flood Zones 3 and 2 are seen only to encroach into the south-western corner and southern boundary of the site, adjoining Mill Lane.

Development of this type, and creation of new residential property, is regarded as More Vulnerable in terms of the Flood Risk Vulnerability Classifications set out within Table D.2 of PPS25.

 

Flood Risk Assessment (FRA)
On the basis of the above we confirm that your new planning application should be supported by a site specific and proportionate FRA, in accordance with the requirements of PPS25.

The required FRA should relate the proposed development to an appropriate flood level (1:100 year plus climate change), should outline the proposed management of surface water and consider safe access / egress from the site during a severe flood event.  To this end we would accept an estimated flood level, as derived from the extent of Flood Zone 2 (1:1000 year), and would require that finished floor levels are set a minimum of 600mm above this level.

 

 

As I had quite a lot of data, both from the EA and courtesy of the FRA that my neighbour had done, I opted to do the FRA myself, on the basis that the worst that could happen would be that they ask me for a better one.  My simple. DIY, FRA was accepted without a murmur, so saving us a significant cost.   Here's a copy of the DIY FRA I did (and I fully accept that it isn't "professional", but it did the job, saved us a few hundred pounds, so I just don't care what it looks like!): Flood risk assessment - redacted.pdf

[Jeremy Harris]

7 minutes ago, Sensus said:

 

According to that, your developed area is not even in flood zone? That's therefore all your flood risk assessment needed to say (as you have said, the rule is that they should be site specific and proportionate).

 

Neither your own nor your neighbour's FRA bears any resemblance to what @KimB will require - they lie at far extremes of the possible spectrum to either side of it.

 

I did just as you've said, just showed clearly that the development was above the flood risk zone.  One page of written text, plus a plan provided by the EA and one by me overlaying our development on the EA data seemed appropriate to me, as the EA had specifically requested that I provide a "site specific and proportionate FRA".

 

The EA did state that the site was in the flood risk zone, probably as they work on a fairly coarse grid:

 

Quote

 

Flood Risk
The site falls marginally within Flood Zones 3 (high risk) and 2 (medium risk) as defined within Table D.1 of Planning Policy Statement 25 (PPS25) Development & Flood Risk.  However we acknowledge that the majority of the site and footprint of the proposed dwelling and detached garage fall within the Flood Zone 1 (low risk) portion of the site.  Flood Zones 3 and 2 are seen only to encroach into the south-western corner and southern boundary of the site, adjoining Mill Lane.

Development of this type, and creation of new residential property, is regarded as More Vulnerable in terms of the Flood Risk Vulnerability Classifications set out within Table D.2 of PPS25.

 

Flood Risk Assessment (FRA)
On the basis of the above we confirm that your new planning application should be supported by a site specific and proportionate FRA, in accordance with the requirements of PPS25.

The required FRA should relate the proposed development to an appropriate flood level (1:100 year plus climate change), should outline the proposed management of surface water and consider safe access / egress from the site during a severe flood event.  To this end we would accept an estimated flood level, as derived from the extent of Flood Zone 2 (1:1000 year), and would require that finished floor levels are set a minimum of 600mm above this level.

 

 

 

[KimB]

25 minutes ago, JSHarris said:

 

The letter I had from the EA did say that the FRA I needed to do should be "site specific and proportionate" to the level of risk:

 

 

As I had quite a lot of data, both from the EA and courtesy of the FRA that my neighbour had done, I opted to do the FRA myself, on the basis that the worst that could happen would be that they ask me for a better one.  My simple. DIY, FRA was accepted without a murmur, so saving us a significant cost.   Here's a copy of the DIY FRA I did (and I fully accept that it isn't "professional", but it did the job, saved us a few hundred pounds, so I just don't care what it looks like!): Flood risk assessment - redacted.pdf

nice... good one indeed!

 

[Jeremy Harris]

7 minutes ago, Sensus said:

 

 The point being, of course that in using that as a cost comparison against a full FRA with hydraulic modelling for a site with complex issues, you're comparing apples with oranges.

 

... meanwhile, what the OP is actually asking about is bananas. ?

 

 

Which is not at all what I was doing...

 

At no time did I even hint that a simple assessment could cost as much as a complex assessment, in fact I've emphasised (twice) that the FRA should be as the EA advised, " site specific and proportionate".  Not sure what bit of that isn't clear, TBH.

 

 

[Jeremy Harris]

1 minute ago, Sensus said:

 

As always with your posts, it's the bit that you omit to mention... you know, the bit that is actually relevant to the question being asked.

 

The implication  of your post (though I'm aware that you will deny any such intention) was to suggest that a professional FRA would be very expensive, yet that they were simple enough to knock up yourself.

 

Neither is remotely true in the majority of cases, including this one.

 

I haven't implied anything to anyone.  You can choose to believe otherwise, that's your prerogative.

 

 

 

 

 

[Mr Punter]

23 hours ago, KimB said:

The archeological side of things we aren't to worried on

 

Don't underestimate this.  It may need you to employ a qualified archaeologist to do a written scheme of investigation, a watching brief where they monitor as you excavate, and a report.  Perhaps budget between £2,000 and £4,000.

 

We used to be able to just make a small donation to the local archaeological society, but now this is "developer funded" it is a full on business!

[Jeremy Harris]

3 minutes ago, Mr Punter said:

 

Don't underestimate this.  It may need you to employ a qualified archaeologist to do a written scheme of investigation, a watching brief where they monitor as you excavate, and a report.  Perhaps budget between £2,000 and £4,000.

 

We used to be able to just make a small donation to the local archaeological society, but now this is "developer funded" it is a full on business!

 

The first plot we looked at had already had a preliminary archaeological investigation, with some early industrial age stuff being found.  When I tried to pin down the costs of the watching brief, and any consequential costs arising from anything uncovered, I found it was a bit like giving them an open cheque book, with all the blank cheques already signed...

 

Because they didn't know what might be under the site, they couldn't give us a price for the archaeological work.  The lowest estimate was for a few days spent looking at excavations and not finding anything to look more closely at, the highest estimate was open ended, as they wanted us to pay for what could turn out to be several weeks of detailed work, uncovering, recording and preserving whatever they found.

 

Be interesting to hear how the big developers deal with risks like this, as they must have ways of being able to put some realistic bounds on the likely cost.  I didn't pursue this further at the time, as a major boundary error, plus the unlawful relocation of a right of way, effectively put the kibosh on the purchase.

[KimB]

50 minutes ago, Mr Punter said:

 

Don't underestimate this.  It may need you to employ a qualified archaeologist to do a written scheme of investigation, a watching brief where they monitor as you excavate, and a report.  Perhaps budget between £2,000 and £4,000.

 

We used to be able to just make a small donation to the local archaeological society, but now this is "developer funded" it is a full on business!

Yes I had meant I knew there would be a large cost involved, as my parents neighbour has just done an extension this year and the English Heritage charged them £9000 to dig the foundations and excavate !!!!! We are factoring this cost into the build.... Annoyingly even though they are right next door, their land is not in flood zone 3, and their extension they've just done is probably the same square footing of what we are proposing to build. How that works, I don't honestly get it????!!!

[Jeremy Harris]

15 minutes ago, Sensus said:

 

Simple and very obvious answer: by doing a bit more work at the feasibility and pre-planning stage.

 

 

 

 

Do big developers just include the full cost of a complete archaeological investigation into the initial budgetary estimates they do when assessing viability?  I can see that working on a larger site, where the archaeological costs might not be such a massive chunk of the site cost.

 

The concern I had was that no one, at least no one within the University of Bristol based field archaeology group, who had already dug two exploratory trenches on the site as a part of the pre-planning work, could give any estimate as to what might be there, or how long it might take to excavate, record and protect/recover anything found.

 

The most optimistic answer was that a watching brief may not find anything of sufficient interest to warrant further work, but they felt that was unlikely given the cobbled floor and artefacts from the old mill that had already been uncovered.  When I tried to get a feel for the most likely cost, things seemed very vague, as the team that had undertaken the exploratory work seemed to have no real idea as to how extensive the area of archaeological interest may be, or how much it might cost to explore in full. 

 

The best guess I could make was that the cost seemed to lie somewhere between about £2k for the most optimistic estimate, to over £200k for a pessimistic estimate.  Trying to pin down a  more realistic cost somewhere in the middle seemed to be impossible.  As the chap at Bristol told me, it was a "how long is a bit of string?" question.   It also seemed clear that we would be required to foot the bill for all, and any, archaeological work done on the site, which I found a bit worrying, as I'd have hoped we might have been able to have some sort of power to veto further work and walk away.

 

 

[Jeremy Harris]

4 minutes ago, Sensus said:

No. DId you not read what I have just written?

 

 

Yes, I did, you said that they did more work at the feasibility and pre-planning stage.

 

My experience was that the work that had already been done at this stage (by the plot vendors) raised more questions than answers.  As I mentioned, the archaeologists seemed unable to be able to give any reasonable answer as to what might lie under the site, or how much it might cost to investigate.   Presumably the answer is to do a full investigation, at considerable cost, before planning.

 

I'd imagine that this is the sort of thing that may happen a fair bit, when dealing with "unknown unknowns".

[Jeremy Harris]

Just now, Sensus said:

 

Perhaps that's because you didn't know what you were doing, or how to manage the process, or the Archaeologists.

 

Not sure how much scope a self-builder has to manage anyone in this position, TBH, even with more experience of having worked with archaeologists.  Outline planning consent had been granted, with a condition that all excavation work had to be overseen by an archaeologist, and when I spoke with the team that had carried out the initial, pre-planning, work, they made it clear that they had the authority to close the site down at any time, if anything was found, for as long as it took to properly investigate it.  It was also made clear that we would have to pay for this work.

 

This is what I meant when I referred to us not having any power to be able to veto further work and just walk away.  It seemed that, if we went ahead, we'd have been accepting a risk that could have absorbed all of our build funds (and more, perhaps) just in doing archaeological work.

[jamieled]

My experience of larger (non-residential) development is that there is often quite a bit of investigation work prior to construction, some of it intrusive, some of it not. It is expensive by the standards of self builders but still proportionate when you consider the overall costs.

[Jeremy Harris]

2 minutes ago, jamieled said:

My experience of larger (non-residential) development is that there is often quite a bit of investigation work prior to construction, some of it intrusive, some of it not. It is expensive by the standards of self builders but still proportionate when you consider the overall costs.

 

 

That makes sense.  I'd guess that a couple of hundred £k of work on a site that's potentially worth a few million is a very different scale to the same amount on a site worth only £100k.

[jamieled]

I meant to add, this will all depend on the competence and experience of the developer-there are easily findable stories of those who don't bother and end up in trouble.

 

You can insure against this risk on big developments, I can't imagine the premiums being cheap though!

Edited October 18, 2019 by jamieled
Clumsy wording

[Jeremy Harris]

On 18/10/2019 at 10:46, jamieled said:

I meant to add, this will all depend on the competence and experience of the developer-there are easily findable stories of those who don't bother and end up in trouble.

 

You can insure against this risk on big developments, I can't imagine the premiums being cheap though!

 

 

Insurance was mentioned to me as a possible option by the planning officer, during a site meeting, when we we trying to put some bounds on cost, but it was difficult to obtain for a single plot, and because artefacts had already been uncovered during the pre-planning work, the premium was estimated as being very high (I couldn't get a firm quote, though - the brokers had never dealt with insurance like this for a single plot before).

 

Had we gone ahead, my plan was to use screw piles to significantly reduce the depth of excavation on site.  At the time I found some stuff about the way screw piles had been used in the past to avoid too much disturbance to buried archaeology, so even though the cost was a bit greater than that of conventional foundations, the reduction in likely archaeological cost would have swung very much in favour of using them.

[KimB]

My architect has recommend we use this independent company for the FRA as he is getting no where with the EA. They are charging £1000 plus VAT to complete the report

https://www.unda.co.uk/flood-risk-assessments/planning/

 

Anyone ever used them or heard about them?

[colin7777]

Kim, look to see if anyone else near has had a flood report done and see what the report is like and if they got the planning approved maybe asking for a quote.

 

When I asked EA I got the feeling that they would be looking for all the reasons to say the area was not suitable for building on, you have also then put all your cards on the table face up

 

Edited November 1, 2019 by colin7777
missed a bit

[jamieled]

@KimBI haven't heard of them and I work in the industry. However, that doesn't mean much in the grand scheme of things as I tend to work on larger scale flood risk jobs. If you can get some recommendations, all the better.

 

As with all professional services, the key aspect is what you are getting for your money. Are you paying them simply to get an independent rubber stamp of something you already know? Or are they potentially going to inform your design?

 

Flood risk assessments can sometimes give clients an answer they don't want, but a good consultant will be able to help steer you through any problems. A bad one will just write a report assessing the level of risk and leave it up to you as to what to do next. The single biggest area of disagreement is usually when a client expects a flood risk assessment to give a clean bill of health and it doesn't do that.

 

If it were me, I'd want to know the scope of their work, will it completely deal with planning requirements, might you need to do any more complicated assessment if this one turns up something concerning etc...?

 

 

[KimB]

Unbelievably we have now come out flood zone 3, so full steam ahead, our next battle is now English heritage. The site we are building on is land next to my parents house and once was on the land of an old Abbey so on the land is Ancient monuments and archaeological interest, my stepfather brought the land 30 years ago, which was 5 years after moving into their home, the land was just a moat/ditch that my parents had filled. They brought the land as a building plot (trying to locate the paperwork on this). There are two listed buildings in the vicinity of our the plot, but are approx 50 meters away. At the moment we have had quotes in of £5000 to complete a SAM statement and archaeological interest.

Eeekkkk has anyone had any similar experience to guide us if this is fair price etc? Knowing that the land is 30 year soil that my parents had filled, it seems highly unlikely they will be finding much of interest but obviously this is a heritage site!