Construction Drawings...What should they look like?

billy_beckham

Hi Folks,

Looking to know what should be contained on a set of "Construction Drawings". How much detail should there be on it?
Eg.

* Should the roof timber sizes etc be listed.
* Should the window/doors sizes be listed.

Basically what should I expect to see?


I ask as I have been sent a set of 4 "Construction Drawings" for review and am not happy. To me they are basically spruced up planning drawings.

1) There's a foundation plan/ ground floor plan which basically just details the steel/lintels for the opes.
2) A Details drawing which looks like a cut and paste from any house, basically Homebond pics of details of rising walls, window cill details, threshold details etc. There's 1 detail of a retaining wall which is specific to our house which is obviously an add in, different font etc.
3) Another which is a cut and paste from the planning drawings detailing the external finishes
4) And lastly a drawing which basically is text, listing out approx. 30 points. This drawing points to the roof and just says consider timber trusses for vaulted roof or similar and approved.


Being charged €2,400 for these and don't feel they are up to scratch.

Thanks,
Billy

Gumbo

billy_beckham wrote: »

Hi Folks,

Looking to know what should be contained on a set of "Construction Drawings". How much detail should there be on it?
Eg.

* Should the roof timber sizes etc be listed.
* Should the window/doors sizes be listed.

Basically what should I expect to see?


I ask as I have been sent a set of 4 "Construction Drawings" for review and am not happy. To me they are basically spruced up planning drawings.

1) There's a foundation plan/ ground floor plan which basically just details the steel/lintels for the opes.
2) A Details drawing which looks like a cut and paste from any house, basically Homebond pics of details of rising walls, window cill details, threshold details etc. There's 1 detail of a retaining wall which is specific to our house which is obviously an add in, different font etc.
3) Another which is a cut and paste from the planning drawings detailing the external finishes
4) And lastly a drawing which basically is text, listing out approx. 30 points. This drawing points to the roof and just says consider timber trusses for vaulted roof or similar and approved.


Being charged €2,400 for these and don't feel they are up to scratch.

Thanks,
Billy

Construction Drawings will be details that are used 100's of times a day on various projects.

Any decent Practice will be copy/pasting them to drawings to avoid duplication of work in the Drawing Office.

What you are paying for are these details on headed paper (Drawing) and Professional comeback should they be incorrect or something goes wrong.

They are not architectural drawings so they will never look "as good" as architectural or Planning Drawings. The point of them is to get the information across on how to get the structure to stand in place.

billy_beckham

I'm not looking for them to "look good".

My issue with them is there doesn't seem to be much detail. No mention of any spec for timber in roof?

The drawing with the details mentions 150mm insulation in the rising wall section, 110mm insulation in the window cill section, and in another section calls for 125mm of pumped insulation?? 3 different thickness's in the external wall? is that correct.

There's a renovation element to our job aswell. Chimneys being removed, opes widened etc. Zero mention of this on any drawing?

To me the only thing they have done is provide a spec for the retaining wall, a Homebond manual could have provided the rest.

sydthebeat

the last homebond manual was from 2015.... so it will be nowhere near applicable to 2019 NZEB regulations.

due to the onerous regulations we have in Ireland, many specifications and details will be "defensive" and thus will be used time and again on a myriad of projects. the details supplied as "construction details" will have been assessed to comply wit the 'acceptable construction details' from a thermal bridge and air tightness point of view. Introducing new details which havent been properly thermally bridge calculated will lead to the possibility of your house not complying with Part L.

as for the roof specification, if the specification calls for roof trusses, then roof trusses it is.
if you want to cut a roof instead, tell the designer and ask them to specify it up... note this may lead to an extra cost.

billy_beckham

sydthebeat wrote: »

the last homebond manual was from 2015.... so it will be nowhere near applicable to 2019 NZEB regulations.

due to the onerous regulations we have in Ireland, many specifications and details will be "defensive" and thus will be used time and again on a myriad of projects. the details supplied as "construction details" will have been assessed to comply wit the 'acceptable construction details' from a thermal bridge and air tightness point of view. Introducing new details which havent been properly thermally bridge calculated will lead to the possibility of your house not complying with Part L.

as for the roof specification, if the specification calls for roof trusses, then roof trusses it is.
if you want to cut a roof instead, tell the designer and ask them to specify it up... note this may lead to an extra cost.

As i've said its basically a jazzed up set of planning drawings with copy/paste from previous jobs, only unique item is the retaining wall.

Is it correct to have 3 different thickness's for insulation in the outer leaf?
Is it correct to have no details at all for the renovation element?
Re the roof, we didn't spec for trusses. Who makes that call?

sydthebeat

billy_beckham wrote: »

As i've said its basically a jazzed up set of planning drawings with copy/paste from previous jobs, only unique item is the retaining wall.

Is it correct to have 3 different thickness's for insulation in the outer leaf?
Is it correct to have no details at all for the renovation element?
Re the roof, we didn't spec for trusses. Who makes that call?

i didnt realise it was a renovation and extension, i assumed new build.

if the drawings dont do what your agreed with the designer, then dont pay until your happy.

specifying trusses where there is an element of joining in with an existing roof is not very practical