It's a ground floor extension at the rear of my 30's semi. The new bit is 4m out 7metres wide, made from 215mm solid aircrete blocks with 65mm PUR foam thermal plasterboard on dabs on two sides. The party wall is a 100mm block cavity wall with 40mm celotex in the cavity (nextdoor also has built the same extension at the same time. The roof is pitched but I have fitted ceiling joists so I have a flat 8' ceiling with 150mm celotex inbetween the joists. there is a patio door which is 12 feet wide by 7ft high, brand new with argon in the units. there are 2 velux windows in the roof, each is 120cm x 120cm. The floor is suspended timber with 75mm celotex between joists, this new bit is open to the original rear room which is 7metres by 4metres and doesn't have an outside wall and also has 70mm celotex between joists.
sadly the calculation is too trickey for me to work out. Could you tell me how much the new part needs and how much the old part needs (the old bit will be kitchen, the new part will be lounge and dining).
sadly the calculation is too trickey for me to work out. Could you tell me how much the new part needs and how much the old part needs (the old bit will be kitchen, the new part will be lounge and dining).