Attic conversion

Tim Robbins

Hi,
We wish to get an attic converted on a new house. The build quality on the house is top notch and comes with very good BER.

We don't want toilet or sink up there but need all the usuals: good insulation, velux windows etc.

I am noticing most people in this game are tradesmen who run their own business (nothing wrong with that). However, I am wondering are there any companies who use architects to quote you and show you what way your attic will be before work begins?

Reason I ask is I don't want to loose the BER and want to ensure things are done to 2008 building regs.

Many thanks.

peter_dublin

If you want an architech designed attic conversion then you should engage an architect. You should then be able to tender based on your architects design and specification or the architect could handle this for you.

Really an attic conversion is not that difficuts leaving aside the structural element. Also getting an architect design does not guarentee quality of finish unless you engage the architect to also undertake site visits.

Assuming you have your home design scheme in terms of finishes already known, the room size is determined already by the building size. the biggest area of effect is in the veluxes. I have seen attic conversions for say 10k with three standard veluxes. I have also seen attic conversions for 20k where they have 2.4meter veluxes creating a glass wall effect with amazing views.

If I were you I would save your money, google for attic conversions to see whats possible and then put together your design and tender for it yourself. It a two to 3 week build which you could easily over see yourself. Badly fitted insulation is obvious and this is the biggest area of danger, but again it's simple, if is looks badly done it is.

Your BER will need to be redone once you convert your attic anyway, so if your new insulation level at ceiling level in the attic is equal or greater than the existing level (100mm polyiso = 300mm fibreglass) all other things being equal it should remain the same.

BryanF

@ Peter, what about air- tightness? Also I wouldn't be sUre about the BER remaining the same
@ the op, one of the benefits of having an arch involved is that they are separate from your contractor. Advising and watching your back

sydthebeat

peter_dublin wrote: »

Your BER will need to be redone once you convert your attic anyway, so if your new insulation level at ceiling level in the attic is equal or greater than the existing level (100mm polyiso = 300mm fibreglass) all other things being equal it should remain the same.

thats an incorrect myth

u value of 100mm of polyiso (TC = 0.023) = 0.23w/m2k resistance = 6.82

u value of 300mm quilt (TC = 0.044) = 0.15 w/m2k resistance = 4.35


Thats a major difference in anyones language.

The equilibrium happens closer to 150mm of polyiso.

shane6977

Agree with BryanF and Sydthebeat.

Best advice would be to engage an Arch Tech / Architect to design the conversion for you. Your designer should be able to provide an initial BER analysis before getting into the detail design. The analysis should enable your designer to specify the most effective insulation for your needs.