who does the drawings

[bluebaron]

I've had some plans drawn up for PP, basically floor plan and elevations. I am going with a timber frame company for an extension.

That are wanting full site plans, section drawings, floor levels, ridge heights etc.

If I was going block then I would have commissioned these drawings, for building control, but surely the timber frame company should take what they can from the CAD plans and arrange a site visit to gain any other information they require? They, of course are designing the timber frame in its entirety.

I can get the drawings commisioned at extra cost but my architect thinks they are passing the buck a bit.

Anyone know who's right here?

 

[freddiemercurystwin]

Why do you think a timber frame company will be able to detail up an extension when their area of expertise is limited to the frame?

If it was steel framed would you think a steel fabricator could be expected to know how to insulate or waterproof the roof for example?

Sounds like your architect is trying to pass the buck. Is it SIPs or a different kind of timber frame?

 

[bluebaron]

The three architects I have spoken to have all said that if a company is designing something they should be resonponible for it.

As such they shouldn't be dealing in drawings by another party.

If I present them with drawings and they base their design on it and it's wrong then there is an area of who is to blame. If one party does it all then responsibility can be established.

That was my argument but happy to hear the other side of the coin?

 

[freddiemercurystwin]

I’ll tell you the typical procedure the architects should be taking:

1) They discuss with the client or make a decision as to the system to be employed – you’ve not said otherwise so I’ll assume its SIPs (if that’s a sensible solution for an extension is another matter).
2) The architects produce their Building Regs drawings based on a typical SIP manufacturers technical information – the different SIP suppliers details are fairly similar.
3) Once a SIP supplier is found and appointed they (the SIP supplier) can use the architects CAD drawings to produce their own setting out drawings of the timber frame.
4) Once the architect receives this in a CAD format he will likely need to refine his own drawings to ensure the whole design works coherently, complies and is buildable etc, checking, liaising with and if necessary getting the SIPs supplier to make any amendments to their design/drawings as the process trundles along.
5) Ultimately you end up with a coherent set of drawings that incorporate the accurate setting out drawings from the SIP supplier.
6) Once on site the builder is responsible to liaise with the SIP supplier and the SIP supplier may well include their own site visit to measure the actual floor slab as its been cast for example to ensure their SIP frame is made to fit the on-site setting out.

As mentioned this is typical so differences in this process may occur but that’s roughly the order of events. None of this alters the responsibility.

There will be a glaring note on each party's drawings:

The architects will say 'Timber Frame design to specialist design/specification'.
The Timber Frame drawings will say 'Waterproofing etc etc design to Architects'.

 

[bluebaron]

Thanks Fred for that comprehensive answer.

I am actually getting an open panel timber frame. One of the reasons I went down this route was I thought how easy it would be!

Being a bit naive I got the drawing done by a friend who used to be an architect. He did the drawings hand drawn. I then took them to a timber frame company and said "design this please"!

They in turn said they needed a CAD design so I paid £360 to get said plans redrawn in CAD. Then they asked for a section drawing, another £90, then they starting asking for a whole host of other stuff.

This is the point I got to two months down the line.

If I need to get a full set of drawing plans done (£2400), I might as well go back to doing it in block work. The main reasons I went timber frame was to avoid having two sets done at considerable cost.

Thanks again. I'll try and negotiate with the frame company to send their guy out and see what costings we can come up with.

 

[freddiemercurystwin]

£2400 is bonkers, should be about £1000 including the CADing up of your hand drawn drawings. This job doesn't need an architect it needs an architectural technician.

 

[chappers]

is this just a straight forward extension or something fancy in oak and glass.
Just find a decent builder who can stick build it on site

 

[r_c]

I’ll tell you the typical procedure the architects should be taking

Thank you for explaining the process.