Loft Heating Requirements

[Lisa Heeley]

Hi I've got an issue with 2 large loft space bedrooms that just don't heat up the room enough.
It's a new build so the insulation in the loft will be correct for building regs.
It has a 588x600 double radiator under the dormer window facing south
2 Velux windows facing north
Window area is 2.685m2
Ignoring the dormer and the angle in the room for the roof pitch the floor area is 4.1m by 5.4m
Built in brick (will have insulation)
Underneath is a heated bedroom.
TRV on radiator
Trying to work out if the builders have put a big enough radiator in.
The dormer is very cold and you can hear everything outside.
Can anyone tell me what the BTU and watts requirement is, so I can be more informed in tackling the developer on the heating system up there.

Thanks in advance

 

[muggles]

Do the radiators get as hot as those in the rest of the house? Have you tried bleeding them? Do things improve up there if you turn the rest of the radiators off?

What are the dimensions in green on my drawing?

 

[Lisa Heeley]

Hi Andrew

Height is 1.07m, under the Velux (slope of the roof)
Ceiling height is 2.4m (insulated loft space above the middle section of the room between the sloping roof)

The radiator gets hot, been bleeding the radiators since I moved in.

Thermostat for first and second floor is in the master bedroom, that has single radiator at front and back, plus big towel radiator in the en-suite - this room underneath the loft rooms on second floor.

Can't turn off 2 rads as they not got TRV's on.

Thanks