Understanding the process of getting a new building approved

[d000hg]

We've spoken to our local council building control department and sent inquiries to some private firms in regard to obtaining building regs approval for a mixed use new cabin building in our garden.
However I'm a little unclear who does what and in what order, etc.

We are thinking to go with a private firm over the council for timing reasons (our council is notoriously slow) - the cabin is on order to arrive in a few weeks and we want to be building it to code rather than fixing it later, in order to get it signed off as soon as it is complete.

I thought building control would tell us what changes are required based on our plans but so far I get the impression they act more to sign off work done by other people. The council guy said they would work with us to figure out an acceptable solution, but a private firm seems to be saying otherwise; they noted as two specific things that thermal and water use calculations would be required. I recall SAP is the process used for the former but for instance does that tell us what changes are required, or merely give an analysis of a given spec?

Can anyone help me untangle this so I at know who has what role(s)? Does a private firm simply do the same work as the council would?

Thankyou.

Project Details
Tried to keep this separate from the above about the general process but for further information:

• The building is a large log cabin, a bespoke variant on this range from Tuin: https://www.tuin.co.uk/70mm-Log-Cabin.html. 11x7m rectangular footprint
• The cabin is not designed to meet regs as-is, as supplied it is a glorified shed in kit form.
• We have detailed plans and spec of the cabin from Tuin
• Foundations are a plinth system from https://swiftfoundations.co.uk/swift-plinth-plus/ - they have speced this for us based on the cabin and a topo survey
• Heating is specced via underfloor electric mats (no gas supply), lighting all LED
• The big thing flagged by everyone we speak to is thermal efficiency and calculations. Floor, roof and (probably, at least some) walls will require insulation fitting and this is something we want to incorporate in the initial build, so is one key thing we want to get specced ASAP. All doors and windows are specced as modern UPVC double-glazed units, exactly like you'd put in your house, rather than the ones Tuin supply.
• The wiring will be done by a fully-registered/compliant company; general construction by a bunch of tradesmen.
• We hired a planning consultant to get planning permission granted, but we do not have an architect since the building itself is essentially pre-fabricated with plans and spec available.

If I missed anything useful just ask.

 

[d000hg]

Ok I got a bit of clarification from one BC company, that they expect all plans and calculations provided as these have to come from "competent people". Which clears that up a bit, but then leaves more confusion what BC actually do. We've had a quote from them for about £2000 inc VAT (by comparison I think our council charges about a grand though I'm not certain https://www.durham.gov.uk/media/28518/Building-Control-fees-and-guidance-notes-1-April-2019/pdf/BuildingControlFeeGuidance2019.pdf). That seems a lot of money for not very much, what is that £2000 actually paying for?

Some unbiased advice from someone not trying to make money out of me, as to how this all fits together would really help.

 

[Notch7]

have you got a price from Stroma -I used to use them they are ok.

in general: building control want plans and spec to be sent in, they do a plan check and send backa letter to either agree or ask for changes in their opinion for approval.

its easy to apply -just upload the drawings online and fill in their online initial notice form.
Stroma send a request to the LA and ask if they are happy for Stroma to do the inspections.
in general you can have the first inspection 7 days following the application.

 

[d000hg]

No come across them, will look them up. So they (or other companies) basically sub out the same task as the council - I'd guess for slightly more money but quicker service

I also had this confusion over the different things/ways you can go about this. An excerpt from my local council's fees list (link above):

Though they do try to explain e.g. Building Notice = Plan + Inspection I'm left a bit in the dark what it all means. I get the impression especially for a new building you can essentially get pre-approval subject to an inspection to do what you said, OR you can just do it and then they have to figure it out afterwards if it's up to spec. Is that what all this is about?

Just trying to figure out what the council will charge is hard enough! Especially because it's not a dwelling per se, but is a separate building. Heated and used during the day but not slept in, etc.

So whether we would be subject to the above table or this one, is one we've been waiting for 3 weeks to find out... we submitted an online request and as yet they haven't told us what they will charge us, let alone how long the process might take!

It's a private building which will also have some business use - kind of rented out - so one BC company advocated to process it as "a granny flat with some public use". We managed to secure some funding but that is contingent on getting regs approval before they pay out, hence not wanting it to drag out!