Query re Building Regs conditions

[Deejay_2]

Hi

We received planning permission on 14 July for double garage with attached habitable area for "granny" and yes it does look like a small bungalow.  We managed to apply for Building Regs before the 15 June date when regulations changed.  We have three pre-commencement conditions 

 

1   Structural calcs (Part A) roof trusses.  We are not having pre manufactured roof trusses and I'm not sure who I would ask to provide these calculations.  Do Building Control normally ask for calcs for a "stick" roof.  Is this a job for the structural engineer.  The guy who did the drawings is not being very helpful so not sure who to approach and Building Control seem to have gone to ground for the summer.

 

2   Drainage (Part H) H4 Build over agreement.  I contacted the Water Authority a while ago who sent me a map and application form to join a nearby foul sewer which we intend doing at some point.  There was no mention of a build over agreement and the sewer is much further away than the 3 metres minimum distance required by the Water Authority.  The sewer connection will be on a public footpath.  Has anyone else come across this and does anyone think I should just apply for the agreement anyway?  (Water Authority also on a go slow ie no response).

 

3   Details regarding Part L - As Design SAPS, as Built Saps and EPC.  I contacted our local authority Building Control to point out the description appearing on the approval notice (and presumably other records) is for a bungalow with a double garage which is incorrect and in no way matches the description on the drawings which is "Garage with dependant relative accommodation".   I explained that the proposal is not for a separate dwelling and is principally a double garage with a bit added on for me, which would receive its services via the existing bungalow.  In the absence of the author of the approval his colleague confirmed that the title would be changed and that as the proposal was not a separate dwelling we would not require to fulfil Condition 3 - SAPS and EPC.  Had I not queried the description I would have been non the wiser.  I have still not received an amended approval or confirmation of the advice given.  Has anyone else come across this situation.  I have included this here as information for anyone else undergoing a similar proposal.

 

Any advice/observations on the above (particularly the roof question) would be very much appreciated.  

 

Footnote:      We hope to get the footings in before the one year transition period is up in June 2023.  I have a question about the feasibility of this but will post it in the appropriate thread.

 

 

 

 

[George]

1. I'm not sure what a 'stick' roof is. If it's not a trussed roof (or any other sort of prefabricated roof) then you'll probably need some input from a structural engineer.  I doubt Building Control would ask specifically about the roof but you'll need a design either way.

 

2. If you're not building over/within the easement then no build over agreement is needed. I'd ask the council about working in the public right of way... they will probably want some way to divert/close it and an application to do so. 

 

3. Errr... pass. Sounds like a mistake. Chase them up, it is peak holiday season.

[ETC]

4 hours ago, Deejay_2 said:

 

1   Structural calcs (Part A) roof trusses.  We are not having pre manufactured roof trusses and I'm not sure who I would ask to provide these calculations. Trusses roofs are designed by specialist truss roof designers/suppliers. They will also do the calculations for Building Control. If you’re not installing a trussed roof then calculations are not needed.

 

Do Building Control normally ask for calcs for a "stick" roof.

Not normally. Only unless your section size and strength grade do not comply with the guidance documents or you are doing something unusual. If standard rafters and ceiling joists then probably not.

Is this a job for the structural engineer. Can be - but an architect can easily read the guidance and specify the section size and strength grade.

 

The guy who did the drawings is not being very helpful so not sure who to approach and Building Control seem to have gone to ground for the summer. A pity. Post your drawings and I might be able to help.

 

2   Drainage (Part H) H4 Build over agreement.  I contacted the Water Authority a while ago who sent me a map and application form to join a nearby foul sewer which we intend doing at some point.  There was no mention of a build over agreement and the sewer is much further away than the 3 metres minimum distance required by the Water Authority.  The sewer connection will be on a public footpath.  Has anyone else come across this and does anyone think I should just apply for the agreement anyway?  (Water Authority also on a go slow ie no response). What are you building over? Is the existing public drainage going under your building? Post your drawings.

 

3   Details regarding Part L - As Design SAPS, as Built Saps and EPC.  I contacted our local authority Building Control to point out the description appearing on the approval notice (and presumably other records) is for a bungalow with a double garage which is incorrect and in no way matches the description on the drawings which is "Garage with dependant relative accommodation".   I explained that the proposal is not for a separate dwelling and is principally a double garage with a bit added on for me, which would receive its services via the existing bungalow.  In the absence of the author of the approval his colleague confirmed that the title would be changed and that as the proposal was not a separate dwelling we would not require to fulfil Condition 3 - SAPS and EPC.  Had I not queried the description I would have been non the wiser.  I have still not received an amended approval or confirmation of the advice given.  Has anyone else come across this situation.  I have included this here as information for anyone else undergoing a similar proposal.

Sounds like a separate dwelling to me and for what it’s worth I’d have separate services and a separate postal number just in case you wanted to separate the garage and accommodation from the existing dwelling at some time in the future.

 

If however you’re sticking with a double garage and associated accommodation then all you will need is more than likely U-Value Calculations for the heated part of the proposal.

 

 

[Deejay_2]

Thanks for your reply.  Sorry I used the term "sticks" which I picked up from the internet - I've looked on our drawings again and the written specification refers to a traditional roof where I believe the timbers are cut on site.  So would I need to ask a structural engineer to supply a drawing (I don't have a structural engineer engaged at the moment, otherwise I'd ask him/her).  Is this something Building Control would normally include in pre-commencement conditions.  I am asking because it could be a mistake as there have been so many made firstly with Planning and now it seems with Building Control.  

 

Although No 3 sounds like a mistake I find myself asking did the original author make a mistake or is the response from his colleague a mistake.  I don't seem able to get a further response to confirm one way or the other - hence my asking if anyone else has an opinion.

 

As these are pre-commencement conditions I need to be clear about what's required as soon as possible so any views would be much appreciated.

 

 

 

[Deejay_2]

Thank you ETC.  The Building Control Officer who issued the approval referred to roof "trusses" which is why I wondered if he had misread the drawing.  I'll try and post the drawing but have new printer and will have to work out how the scanner works so it might be a while.  Thank you though for your input which has at least confirmed that I should check this out.  As far as I am aware there is nothing special about the roof but I'm no expert. 

 

As regards the drainage we're not building over anything.  We do have to get permission to close the footpath but this will be with the Local Authority as and when we're ready.  So again, not sure why a Build Over agreement is required so will question this further.

 

Principally the proposal is for a detached double garage for the occupiers of the original bungalow (my son) with a small flat for myself added on. We already have the limit of 5 dwellings on our private road so a further separate dwelling would not be allowed.  We have increased the wall and floor insulation thickness and hope the living area won't require much heating.  We'll see if they come back for U-value calculations which would seem a reasonable request.

Thank you for your input which has been really helpful and I'd be grateful if you would look over the plans if I manage to upload them.

Best regards.

 

[Temp]

1) How big and complicated is the roof? It wouldn't be expensive to get a Structural Engineer to just specify the dimensions of the rafters for a conventional pitched roof, fair bit more if the roof needs to be designed due to its size, shape and complexity. 

 

2) If the sewer is far enough away that a build over agreement isn't required I would submit a letter stating that fact and attach a site plan and perhaps a copy of the water authority. 

 

3) You might not need an EPC but you will probably have to provide some evidence it will comply with the relevant bits of Part L. Wall construction and U-value calculations probably. Window details.

 

What drawings did you provide with you Building Control Application? Was it a full Application or just a Building Notice?

[markc]

As above, unless it’s a very complex roof or joins into an existing then a roof truss company can/will design the roof structure and give drawings and calcs (the design software spits this stuff out).

[Gus Potter]

6 hours ago, Deejay_2 said:

We received planning permission on 14 July for double garage with attached habitable area for "granny" and yes it does look like a small bungalow.

Good news then on two counts. Getting approval and it looking more like a house than a garage!

 

5 hours ago, George said:

I'm not sure what a 'stick' roof is

I love the different terminology as you move about the country. A really experienced Lanarkshire sparkie I used to work with vaguely pointed to a space in an attic conversion and said.. do you want the cable tray in the Camsile? Turned out it was the space behind the vertical soldiers (vertical struts also called the box member). Yes folk also use the term "cut roof" meaning the roof is cut from loose timbers.. a traditional roof

 

2 hours ago, ETC said:

If you’re not installing a trussed roof then calculations are not needed.

Check this as it will depend on the the wind bracing you need, the loads and connections not just between the timber members but also between them and the rest of the structure. The prefabricated truss manufacturer's tends to stay away from this part of the design... the stability system and load transfer to the structure below.

 

You may actually find your stick roof is the most cost effective option.

 

Would be interested to see your plans also.

 

 

 

 

 

[SBMS]

We are having a similar roof (our SE referred to it as ‘loose’ which I guess means the opposite of trussed). In any event our BCO asked for SE drawings for the roof steels, timber sizes etc. I guess they want their engineers to check your SE hasn’t designed something woefully inadequate (like 2x1s or something!). 

[SBMS]

How come your roof isn’t trussed? Is it going to be a habitable space? We wanted attic trusses but couldn’t get the height so had to go traditional which was a lot more expensive. 😩

[George]

I'd have guessed it meant a cut roof. 😜

 

If it's a habitable space you can still get prefabricated attic frames. They're more expensive than trusses (larger timber sections) but still saves on site labour. For a new build I'd avoid site built cut/stick roof wherever possible. 

[SBMS]

5 minutes ago, George said:

I'd have guessed it meant a cut roof. 😜

 

If it's a habitable space you can still get prefabricated attic frames. They're more expensive than trusses (larger timber sections) but still saves on site labour. For a new build I'd avoid site built cut/stick roof wherever possible. 

Yeah we did want to do attic trusses for our roof but because we have two different roof heights we weren’t able to get the height needed with manufactured attic trusses. Very frustrating as added a lot of labour cost!

[ETC]

2 hours ago, Gus Potter said:

You will not need calculations for your cut roof if you stay within the specified section sizes and strength grade shown in the guidance. See http://www.buildingcontrol-ni.com/assets/pdf/TechnicalBookletD2012.pdf.

You will - as I said earlier - need a structural engineer to submit calculations on your behalf if the structure or design of your roof is unusual, or outside the scope of the guidance. Yes - I know this is Northern Ireland’s Technical Booklet I’ve referenced but it will show section sizes of rafters for certain spans and roof pitches.

 

Check this as it will depend on the the wind bracing you need, the loads and connections not just between the timber members but also between them and the rest of the structure. The prefabricated truss manufacturer's tends to stay away from this part of the design... the stability system and load transfer to the structure below.

The truss designer/manufacturer will design the bracing for the roof and the remaining lateral restraint is standard practice for truss and cut roofs. Lateral restraint is required at wall plate level and at ceiling and rafter level. See  http://www.buildingcontrol-ni.com/assets/pdf/TechnicalBookletD2012.pdf. Any joiner worth his salt will know how to do this. It’s not rocket science. You may however need wind bracing for your cut roof and for that it’s worth checking out the relevant BS.

 

You may actually find your stick roof is the most cost effective option.

Depends on a number of factors including section size, if purlins are needed and span. Personally I’d go with trusses - might be a bit more expensive but it’s a one stop shop and the design and fabrication liability rests with a single party.

 

 

Would be interested to see your plans also.

 

 

 

 

 

 

[Gus Potter]

3 minutes ago, ETC said:

Any joiner worth his salt will know how to do this.

Good point ETC.. but those that do are few and far between.. and if they do they have often moved onto better things.

[ETC]

4 hours ago, Deejay_2 said:

Thank you ETC.  The Building Control Officer who issued the approval referred to roof "trusses" which is why I wondered if he had misread the drawing.  I'll try and post the drawing but have new printer and will have to work out how the scanner works so it might be a while.  Thank you though for your input which has at least confirmed that I should check this out.  As far as I am aware there is nothing special about the roof but I'm no expert. Take a photograph with your phone and upload it.

 

As regards the drainage we're not building over anything.  We do have to get permission to close the footpath but this will be with the Local Authority as and when we're ready.  So again, not sure why a Build Over agreement is required so will question this further. Sounds like your BCO didn’t understand the proposal.  By the time you’ve got permission to close the footpath your builder would have the connection finished. It really isn’t complicated unless the existing sewer is deep and you need to close the footpath for a few days. Nothing really to be worried about. Your builder will look for a connection point as close to the proposal as possible.

 

Principally the proposal is for a detached double garage for the occupiers of the original bungalow (my son) with a small flat for myself added on. We already have the limit of 5 dwellings on our private road so a further separate dwelling would not be allowed.  We have increased the wall and floor insulation thickness and hope the living area won't require much heating.  We'll see if they come back for U-value calculations which would seem a reasonable request. U-Value Calculations can quite easily be done online in a few minutes or by a quick phone call to your local Kingspan/Xtratherm rep.

Thank you for your input which has been really helpful and I'd be grateful if you would look over the plans if I manage to upload them. No problem. Happy to help.

Best regards.

 

 

[nod]

No BC won’t be interested in what is on your drawings Just that everything meets building requirements 

 

Our drawings correctly  show Attic trusses on our garage workshop 

But incorrectly show a steel ridge beam 

The back of the house show cranked steels 

Again wrong 

BC didn’t care that we have used double steels Only that they are seated on the correct pad stone and bolted correctly 

[Gus Potter]

3 minutes ago, ETC said:

By the time you’ve got permission to close the footpath your builder would have the connection finished.

Until you find out they have made a complete bollocks of it, ask who foots the bill then?

 

Yes Kingspan have a good U value calculator for basic calcs.. it's off line for now as getting tuned.

 

 

 

 

 

 

 

 

 

[PeterW]

18 hours ago, Deejay_2 said:

Drainage (Part H) H4 Build over agreement.  I contacted the Water Authority a while ago who sent me a map and application form to join a nearby foul sewer which we intend doing at some point. 

Bear in mind if this is a public footpath your contractor willl require a street works permit and apply for the closure which is around £500. On top of this they will have to have a permit from the sewage provider / water authority to connect, and you’ll need to pay an additional connection charge which is normally £3-600 plus you will require an inspection when the connection is completed. Depending on the size of the lateral / foul sewer and it’s flow, you may need to use a break and join rather than a saddle, this could require pump over when you need the connection installing so… that could be another £1-2000 depending on how long and how deep …

 

I would first consider connecting to your own current foul drains connection in the current property before going down the route of what could be a £3-5000 connection cost to what appears to be the nearest point ..!

[Deejay_2]

 

1 hour ago, PeterW said:

Bear in mind if this is a public footpath your contractor willl require a street works permit and apply for the closure which is around £500. On top of this they will have to have a permit from the sewage provider / water authority to connect, and you’ll need to pay an additional connection charge which is normally £3-600 plus you will require an inspection when the connection is completed. Depending on the size of the lateral / foul sewer and it’s flow, you may need to use a break and join rather than a saddle, this could require pump over when you need the connection installing so… that could be another £1-2000 depending on how long and how deep …

 

I would first consider connecting to your own current foul drains connection in the current property before going down the route of what could be a £3-5000 connection cost to what appears to be the nearest point ..!

Thank you for the above information.  Although I am aware of the requirements to join the sewer I had no idea of the costs involved. 

 

The sewer we would like to join runs across the back gardens of the bungalows on the street to the west of the proposal so the footpath between two of the properties would be the only place to connect.  Our current bungalow is served by a combined sewer in the private access road - it is not very deep and we take great care of it. The new proposal sits considerably lower and approx 20 m from said sewer and would presumably require a pump which we hoped to avoid. 

 

The proposed new connection is approx 20 m from our proposal with a slight downward slope so this seemed the way to go.   I have spoken to a grounworks company (this was many months ago) who just said they take care of the path closure - we just have to get permission from the Water Authority - but as yet no costs have been discussed.  I was waiting until I'd sorted out the precommencement conditions before inviting him to quote but your post has given me the information to ask the right questions.  Many thanks.

[Deejay_2]

Thank you for all the responses.  Our original plans had a straight habitable roof but planning wanted a much lower single storey building which is why it now looks like a bungalow and presumably this is why a traditional cut roof is required.  I am hopefully attaching some drawings that will help.  I have a written specification and layout plan but something's gone wrong and I'lll have to wait until someone comes along that can help.  I am keeping my fingers crossed that I have not ended up with a difficult roof as that was never intended.  I hope that what I have attached so far is OK and look forward to any comments.

Plan Garage Section 14 6 22 Build hub PDF.pdf Plans Elevations 14 6 22 (3) Buildhub pdf.pdf

[ProDave]

7 minutes ago, Deejay_2 said:

Thank you for all the responses.  Our original plans had a straight habitable roof but planning wanted a much lower single storey building which is why it now looks like a bungalow and presumably this is why a traditional cut roof is required.  I am hopefully attaching some drawings that will help.  I have a written specification and layout plan but something's gone wrong and I'lll have to wait until someone comes along that can help.  I am keeping my fingers crossed that I have not ended up with a difficult roof as that was never intended.  I hope that what I have attached so far is OK and look forward to any comments.

Plan Garage Section 14 6 22 Build hub PDF.pdf 144.81 kB · 0 downloads Plans Elevations 14 6 22 (3) Buildhub pdf.pdf 68.23 kB · 0 downloads

What are you trying to achieve?

 

There is not enough headroom for either of those roof spaces to be habitable so at best you are creating storage space.  I don't see why standard trusses would not do those.

 

[Deejay_2]

19 minutes ago, ProDave said:

What are you trying to achieve?

 

There is not enough headroom for either of those roof spaces to be habitable so at best you are creating storage space.  I don't see why standard trusses would not do those.

 

Thank you and sorry I didn't explain clearly.  Our original plans showed the roof as habitable space but we had to lower it to such an extent for Planning requirements that it is now storage space only.  When you say standard trusses do you mean trusses that are not pre manufactured ie traditional cut roof.  I'm still trying to work out what the Building Control condition requires (as in my first post) and if I need to submit calculations who would I ask to do these.  

[ProDave]

No I mean trusses from a truss manufacturer that will do the calculations for you for BC

 

Either the thin W trusses, or attic trusses but make it clear you are not expecting habitable height space, just the maximum clear space that is possible for storage.  Attic trusses tend to have a chord across at ceiling level which will limit your already limited headroom. ask if it is possible to omitt that?

[Deejay_2]

12 minutes ago, ProDave said:

No I mean trusses from a truss manufacturer that will do the calculations for you for BC

 

Either the thin W trusses, or attic trusses but make it clear you are not expecting habitable height space, just the maximum clear space that is possible for storage.  Attic trusses tend to have a chord across at ceiling level which will limit your already limited headroom. ask if it is possible to omitt that?

That's really helpful and clarifies things for me.  I phoned an Attic Truss company a while ago and got a negative response regarding supplying a traditional cut roof but I can see I wasn't asking them the right questions.  We did use them in the past for attic trusses on a new build house, but the traditional cut roof has confused me and I probably confused them.  I'll phone them again and see what they say. Thank you.

[George]

46 minutes ago, ProDave said:

No I mean trusses from a truss manufacturer that will do the calculations for you for BC

 

Either the thin W trusses, or attic trusses but make it clear you are not expecting habitable height space, just the maximum clear space that is possible for storage.  Attic trusses tend to have a chord across at ceiling level which will limit your already limited headroom. ask if it is possible to omitt that?

I'm going to be really pedantic... 

 

They are attic frames, because they aren't triangulated so they aren't trusses. 

 

Sorry.