Any experience with Small Building Structural Guide and verification

[HighlandHopeful]

Hi all,

We have designed our new home using the Small Building Structural Guide, as per Section 1.0.5 of the Building Standards Domestic Technical Handbook which states: "The Small Buildings Structural Guidance (SBSG) provides structural guidance to designers of small domestic buildings on how to comply with Standard 1.1 [of Building Standards]... The SBSG has been written for those with expertise in building design and construction but not necessarily in structural engineering design. Where the conditions or parameters fall outside the scope of the guidance, then specialist advice should be sought from approved certifiers of design, chartered engineers or other appropriately qualified persons."

The proposed house being within all the parameters set out in the SBSG - including size, dimensions, height, pitch, loading, altitude, wind speed, snow zone, ground conditions, wall type and foundation type. Therefore in our building warrant application, we set out the design calculations as per SBSG.

So we used this method, endorsed by the Building Standards, and sent off with the warrant application to be verified by the Council.

The building warrant officer in their first round of comments have said that they don't have resource in house to verify our structural design themselves, so would need to use a third party, which could take up to 12 weeks, and did we want to instead go down the SER route to save time. I hadn't made my mind up on this, but thought I would contact some engineers on the SER to see what are options are. The two I contacted so far have said that the level of detail we have provided is not what they are used to working with, have declined to work with us and suggest we get an architect/engineer. But we have followed the methodology as set out in the SBSG endorsed by BS, including design for walls, roof, lintels, foundations, floor, and how to present the design.

I'm a bit stuck, BS is saying it's ok to use SBSG, but then there are no verifiers available at the council, and if they go third party or we do, the engineers aren't happy to use SBSG... If this was never going to work out for us, I wish the BS didn't mention the SBSG, as I wouldn't have spent every weekend for months doing the structural design, calculations and drawings, if in the end I'm going to have to pay someone else to do it anyway. 

I'm not asking for advice about where SBSG was appropriate to use, I know it is as our house falls within all its parameters, and its use is referenced in the BS, just asking if you think I should stick to my guns and wait it out with the council, find a different verifier who is familiar with SBSG (I only contacted 2 on the SER, there are many more), cut my losses and pay a structural engineer to produce what we need to satisfy building control... Anyone got any encouragement, experience or pearls of wisdom?

Thanks.

[JohnMo]

Simple in Scotland - you need to comply with Scottish building regs. Not a general book. English and Scottish structural design is slightly different also due to higher wind loadings in Scotland, plus insulation required is more stringent, if you haven't seen that yet - for your as designed EPC.

 

Get a structural certificate, so one structural engineer provides full structural drawings etc.

 

If not provide all calculations and BC will get a third party structural engineer to verify and certify for council. I say quicker cheaper to structural engineer certification. That will be 12 weeks plus a couple of revisions and questions, so maybe 16 to 20 weeks. Certificate accepted at face value.

 

Penny pinching just costs time and maybe more money in the long run.

 

 

[HighlandHopeful]

Hi John, thanks for your response.
 

3 minutes ago, JohnMo said:

English and Scottish structural design is slightly different also due to higher wind loadings in Scotland, plus insulation required is more stringent, if you haven't seen that yet - for your as designed EPC.

The SBSG is Scottish and for design of houses in Scotland.

 

4 minutes ago, JohnMo said:

Get a structural certificate, so one structural engineer provides full structural drawings etc.

 

This might be what I have to do if below doesn't work.

4 minutes ago, JohnMo said:

If not provide all calculations and BC will get a third party structural engineer to verify and certify for council. I say quicker cheaper to structural engineer certification. That will be 12 weeks plus a couple of revisions and questions, so maybe 16 to 20 weeks. Certificate accepted at face value.

 

This is what we've started with in our building warrant application. I'm worried that the third party verifier won't accept SBSG-approach, so we'll be back at the beginning needing to get a structural certificate... on principle I want to stick to my guns and say if SBSG is suggested by BS then this approach should be verified, but worried I'm going to spend months in a stale mate and then have to get a structural cert anyway. Wondered if anyone had experience on this sort of scenario.

 

Thanks, I appreciate your insight.

[JohnMo]

Just had a quick look at the document - published in 2010, assume you are going to be working with 2022 building regs, so it's a little out of date. (Unless you have a newer version)

 

Doing stuff out the norm is fine, but the building warrant system is all about ticking boxes. If they cannot tick, you end up paying in time and unplanned expense.

 

You have a choice to make, carry on as you are - or comply, 'as resistance is futile'.