Can any Builder/loft converter help?

Legacy_user

How do I work out the finished ceiling height?

UK,Dormer Conversion. Rafter and Purlin Roof. Full Plans Application submitted by architect. Letter received from local council about 10 weeks later, titled Full Plans Approval Conditional. It states Plans have been examined and conditionally approved as complying with building regulations and sections 19, 21, 25 Building Act 1984. If work is not completed in three years the plan is of no effect. There is one Condition on the back of the letter and that is: Provide cross ventilation on the flat dormer roof.


Plans on very large paper to allow builders to provide written quotes from the same plan which has calc’s, named branded materials with length, width, height etc, where to double existing timber for strength all set out on the plan. It has room dimensions length and width, all existing rooms, existing and proposed loft room and a cross section showing dormer and stairs. The only thing missing is head height in every area including all proposed and existing, but Borough Council Building Control has seen and approved the plan conditionally for a large fee and a further fee due on first inspection.


The plan sat in a drawer, no rush. A year later I phoned architect as we couldn’t remember the finished height although 220cm stuck in my mind from word of mouth. He offered to send a pdf with the height on, which is stated as 220cms. We use the PDF to email and gain written quotes. Local authority obviously don’t have the PDF as it was sent a year later.


We selected one company. He gave us the news that it would not be as stated 220cm but would be 198cm which is an average finishing height, but 20cm above stairs, luckily. We received his itemised written quote but contacted him to tell him that we are no longer having it done due to the finishing height, thanked him for his time and honesty.

When the loft company called he marked the neighbouring wall which is a brick cavity 16cm under the apex ridge board which is 20x5cm.
Also put a mark 24 cm above the ceiling joist which are 7x5cm.
However he apologised as he hadn’t taken notice of the joist size on the plan, so not too sure if this bit is helpful as on the plan they are 175x50mm but marked up for something different.


A few days later we couldn’t understand the difference and I suddenly recalled the architect said 240cm ,word of mouth only. So we measured it ( 100 yr old ceiling joists up there not very safe) 238cm neighbouring wall from under apex ridge beam to top of the thin ceiling joists, 237 opposite chimney/gable wall 235cm, middle areas 232cm and 230cm. Could the weak ceiling joists have moved since the architect measured it, they now seem to rise up where they join/butt. Don't know correct terminology.


I think I recall him saying, as we are having a full reroof (never been felted in its history. Just back pointed) will allow roof/ceiling materials to be put above the roof rafters and just plasterboard and skim would be taken off the ceiling height. I could be wrong. Please can you advise?


So if he did say 240cm existing and 220cm finished head height then all materials should equal 20cm (200mm) . That bit of maths I can do, but does it apply? We can’t read drawing plans. Does this all make sense to you ?

Existing = Rafters 7cm x 5cm, Perlins 27cm x10cm , ceiling joists 7cm x 5 cm roughly 40cm apart. Apex ridge board 20cm x 5 cm

The plan says:

DORMER ROOF–
membrane on 19mm ply on firings for falls 150 x 50mm joists at 400 c/c TRI ISO Super 10 insulation Counter battens Plasterboard and skim finish 70mm Kingspan between joists, ridge beam 2 No. 300x50+6mm plate.

ROOF
Upgrade front rafters to 125x50 sloping ceilings to allow for TRI-ISO super 10+ Insulation & 50mm air space. counter battens Plasterboard & skim finish. 75mm Kingspan Insulation.

DORMER SIDES – I haven’t stated as its not relevant to height.

PROPOSED FLOOR LAYOUT–
Back dormer side says - Beam A 2 No. 225x50 stops at top of wall, another starts Beam B 3 No. 300 x 50 C24 ends at chimney breast/gable end.
Front of property says -Opposite side Beam C 2 No. 300 x 50+10mm plate from chimney breast/gable end to neighbours wall.
Floor Joist 175 x 50mm at 400 c/c, 22mm Floor Boarding. Shows 12 joists on plan. Then Trimmer 2 2 No 175x 50, then Trimmer 1 3No 150x 50. For stairs


OK if doesn’t make sense but thought I would add just in case it does.
We are going to get another reputable company in, or maybe a joiner/builder to provide a written quote. We will not mention anything but wait for the quote as we did with the last company, fair that way. Then we can decide where to go from there.


Please can you advise further especially with what style of roof and if you are sure that local authority must have head height somewhere on their part of the plan?


Thanks again for your time.

Furts

Common sense has to apply with your actions. I have a room in a roof. It is floored and insulated so it is suitable for habitable use. Building Control could not care less about the headroom. It is about 1900mm. It has lighting, inter connected smoke alarm and sockets (so an electric heater can be plugged in). Grab rails, guard rails and barriers are all present, but it only has access via a Youngmans loft ladder. It is illegal to use it for habitable use. It is signed off/blind eye turned by Building Control because I and they know the score. There is no way I would allow children or elderly people to go up and down the loft ladder. I would not be allowing a bed to be placed in the room.


The common sense approach is regulations exist for a reason. If you intend to evade them then you are thinking about illegal actions.

System

I really don't understand how you have got so far in the process and the critical detail is apparently missing?!
In your other thread you say that you have building regs approval, if so, there must be a drawing showing the height at least at a stair landing, there must also be a drawing and spec which details the insulation and roof buildup (a difference in the way it's insulated might explain the difference if it's a different spec to the way the loft company would do things)
The architect should easily be able to tell you height, even if there's not a written dimension it is possible to scale the drawing to measure within a few mm - a difference of 220mm is huge for a loft conversion and bringing it below 2m would mean a stair landing doesn't comply.
The good thing is, you have a full sized model to work it out! Is there no sections drawings showing exactly where everything sits? All you have to do is measure it out

System

UK,Dormer Conversion.

System

Can you post/pm the pdf of the drawing you have? it's impossible to understand why there's such confusion when you have approved drawings

System

Thanks
Forum doesn't allow me to send attachments,

Thanks for everyone's help and advice

System

You could put it on Dropbox or Google drive etc and pm a link to it, if it doesn't let you post a link, just take out some punctuation!

System

Hi , Furts
Not sure if you answered my question.

UK- Do I need to inform local authority if I board a loft for storage? Would never, ever do anything illegal. Wouldn't need sockets etc and would have a light that plugs in on the landing below.

Thanks again

System

Thanks, the-r-sole but that's way above my skills, I can just barely navigate this forum.

I'm going to get another company in, also contact Building Control to ask a few things before calling them out to the first inspection, if we decide to complete it. I've a feeling the architect is more reliable and skilled in what he does and in what materials to use to gain the best height etc as he's semi-retired. I'll let the forum know how I get on in the future.

Thanks for all the advice