Measurment point

[Andrew Welham]

When drawing plans for a new extension at what point do you start your measurements?? i.e the top is the building is X high , from which point ??

Thanks Andrew

[6]

The ground seems pretty logical to me....

[Ian Stirling]

The mean level of the property, the mode, median, or mean of area to be under the property, ....

And if you happen to the year before have built up the area that you're now building in by a couple of meters, then what?

[Dave Fawthrop]

|When drawing plans for a new extension at what point do you start your |measurements?? i.e the top is the building is X high , from which point ??

On all plans you state everything in excruciating detail. state your datum "present ground level at the NE corner" or whatever. In my area sloping ground is always present.

[Phil L]

You can't draw plans for a new extension unless you can calculate what depths of concrete and counterbalances for rafts,what size and shape steel reinforcement for concrete, what size steelwork for spanning openings and load bearings for that.

And:

Wall construction, including dimensions, Kn/m of wall materials, U value of wall insulation, catnic sizes and load bearings. Floor construction, including depth of excavation, amount of MOT, depth and U value of insulation, depth of concrete and size and type of reinforcement. Ventilation requirements. Roof insulation requirements. Electrical requirements.

And:

Drainage, including details of all manholes, rodding points, new drains and their respective manholes, rodding points and size and type of construction.

Roof, including load bearings for roof timbers, pitch of roof, what code lead for flashings, type of timbers to use (C16 etc), details of roof restraints and spacings.

All this and a lot more needs to be included with any plans, and they also need to be to scale.

If you are just drawing a rough plan to show people, then measure your living room from floor to ceiling and add on 300mm, 150mm below DPC and

150mm above ceiling height.

[Tony Bryer]

In my plan drawing days my datum was always ground floor FFL.