Finished floor height

gummibear

Hi all,
started excavations last thursday on new build. site has a slope and house footprint falls from the back right corner of house to the front left corner. back left is at contour level of 100m approx and front right is just below 99m. about 4 to 4 1/2 ft fall. anyway contractor is wondering how much to dig down into site. he(and us too) would prefer to build up left hand end slightly rather than bury the house too low. In the planning decision it mentions finished floor level of 99m!!!! (we would have to dig another 4 to 5 ft min for foundations after this so potential of excavating to 8 or 9 ft on right hand side!) how strict would the council be on this. higher land off to the left of our site so would have slight concern re: run-off and potential flooding (only slight). Engineer coming out in the morning to have a look but if he is not willing to sign off on it am I banjaxed???:(

Slig

Your planning permission drawings will have a proposed FFL in relation to Road level. If you change this then you will not be in compliance with planning permission. You also cannot move the house around the site for the same reason.
500mm is not a large amount and will probably not be noticed but check with the professional certifying compliance. If they dont have a problem signing that it is in substantial compliance then its on their heads.

Villain

A relative is currently building a house that has a FFL of 3m below the roadway because their house is a very large two story.

What pitch is on your roof on the drawings? If its high you may be able to get the council to agree to lowering the pitch and rising the FFL which would result in the same height but allow you a higher FFL. The min pitch for slates is 22.5 degrees I believe.

sydthebeat

id be very slow to change the pitch...... this can make the house appear squashed and take from its aesthetics completely.

Its the certifiers call to be honest, but consider that this 500mm may require a suspended ground floor..... this could be a significant extra cost to you....

whats the 99m level in relation to?... the road?

Quazzie

I think the 99M is in relation to both the road and the roads position above sea level. the road is a certain height above sea level and the 99M is the height of the floor above sea level and is measured in relation to the road. I think this is it..

muffler

Quazzie2002 wrote: »

I think the 99M is in relation to both the road and the roads position above sea level. the road is a certain height above sea level and the 99M is the height of the floor above sea level and is measured in relation to the road. I think this is it..

I think what syd was trying to establish was where the 100m TBM was located. Then it gives an idea as to how the FFL of 99M is relative to where the TBM is.

Quazzie

Was my perception of the FFL correct Muffler.. I kinda half guessed that. but i could be totally wrong..

Slig

depends on who surveyed the site. Generally there is a temp datum of 100m taken somewhere on site (nail in road etc) and all levels will be taken in relation to this.
It would be very convenient (suspicious) for the road level to be exactly 99M

Quazzie

I've no doubt you are right slig.. like i said.. mine was just a guess.. soz if i threw anyone off

gummibear

sorry guys -been very busy and didn't get back to you till now.
the 100m and 99m are above sea level. these are the contour lines diagonally crossing site, not at road level. dprmer bungalow so cant really mess with roof pitch. 38 degrees by the way AFAIK....
all immaterial now anyway as the engineer said the FFL of 99m must be upheld and the foundations were poured today. not worried about water anymore as we had about 12 hours of heavy rain yesterday and site is bone dry today. great drainage. onwards and up(down)wards!!! thanks for replies guys.:)

Mcsirl

quick question on FFL pls ….

New houses are being built directly behind me and using my current back wall as the boundary wall , their is currently lads out there working on the one behind me which still has it least 2 brick heights to go to reach floor level, and from standing at my kitchen I can see from the middle of their chest up.

Can the ffl of the house behind me be significantly higher and is there a a maximum this can be ?

Thanks

Mellor

https://www.boards.ie/discussion/comment/122588729#Comment_122588729

The FFL of the house should be whatever was approved.
There are a number of factors, but there is not limit relative to your FFL