Staircase install

Yes. It is possible to install the staircase before starting the main loft conversion, provided it is designed now as part of the eventual loft conversion and the temporary arrangement is made safe.

Hi, In order to pre fit the final stairs you would need the final floor finish and the trimmer in place (Trimmer=Structural beam that the stairs rests upon). This is determined by the structural engineers design and calculation for the new loft floor and intern the trimmer dimension. So, in theory ,yes, you could fit stairs to a temporary trimmer and try to calculate the final finished floor height, but i'd strongly recommend not to, as your compromising on final finish and actually creating more work in the long run. With a bungalow loft conversion the stairs would actually be installed towards the finishing stage of the project, the ceiling cut out and stair installation by a competent contractor, experienced with these works should be able to install them with minimum disruption to the existing GF.

Yes the stairs can be and often are fitted before the upper level is started simply for access

The most important thing is to know what your finished floor level in the loft is. Assuming there is enough floor structure in the loft to securely attach the top of the stairs to, you have to make sure the landing or top tread smoothly transitions to the floor otherwise you finish will be ruined

Yes, potentially—but treat it as the first phase of the loft conversion, rather than a temporary installation. 1. Finalise the loft design first. The stairs must suit the finished upstairs floor level, future landing and dormer headroom. 2. Have a structural engineer design the stair opening and supports before cutting any joists or roof timbers. Some upstairs structural work may be needed now. 3. Agree the phased work and temporary safety measures with Building Control before starting. 4. Securely prevent use until safe headroom and a completed landing are available. Any opening needs appropriate fire protection, insulation and guarding. 5. Expect some later disruption downstairs from steelwork, flooring and services, so leave final decoration around the stairs until the loft is finished. Getting the design agreed now will help avoid paying to alter or replace the staircase next year.