Take your plans to an architectural technician and ask him for building control plansand working drawings (assuming the plans you have, have passed planning) they will work up the designs to a more comprehensive document your builder can build from. But yes likely to be another £700-£1000. He...
Good luck, if a conservation area they will not like the street scene changing. Yes you need planning permission approval and also consider structural and fire for building control... But I think TBH you are wasting your time. Look for land or a garage nearby!
For a full plan submission you need plans for the work with a specification... It is also to be noted that you now have a CDM requirement (health and Safety) look it up... I suggest you employ someone to look after the work for you be it a Principal contractor or principal Designer.
It is my understanding that you cannot serve notice retrospectively suggest you get the repair work done and try to reassure the neighbour an independent structural engineers report on stability may help reassurance.
If the inner side part of a room, yes you do need to insulate... The construction detail can be tricky you will need a vapour control barrier also. The type and thickness will depend on a number of things. If not done correctly you could have problems. Suggest you seek professional advice.
Some times the steel suppliers can provide the calcs... If not, I suggest you have a structural engineer for calcs for building control. Presumable you have records of what steel went in and pictures of it sitting on pad stones or a sound bearing. If not he may want to do investigative work to...
Talk to your local building control dept.. Not new!... I had a beam installed in a ground floor flat that we removed a wall... Under a competent person app. with beam size with loadings a provided to building control.
The cavity is not sealed at the top will vent into breathable part of roof. A good set of working drawings will help you to understand this detail. The amount of moisture into the cavity is minimal and weep hole and cavity trays can deal with this. (The concrete at footing level in the cavity is...
Clear as mud isn't it! But then that's the PD rules... Suggest a lawfulness cert is a good way forward at design stage (only half the planning fee at this stage!) and if the planning dept deems it requires a full app then you have not cost yourself money but easy to comply and negotiate with...
any moisture in the cavity is directed back to the outer leaf via cavity trays and dealt with by weep holes the wrong type of insulation can prevent this.
As someone else has already said Damp and consequently loss of insulation performance.
Any damp that penetrates the otter leaf has a chance of tracking onto the inner leaf via the wrong type of insulation fitted as fulfill. Check with the manufacturers recommendation of the insulation before...
read the manufacturers instructions... phenolic boards required at least 25mm clear cavity... there is nothing wrong with your 50mm insulation plus 50mm cavity. but there could well be everything wrong with the 100mm fulfill wrong insulation, this will cause future problems.
if you are applying as part of other works the size of the loft area to be developed comes into play, as the amount of extra development. There is a percentage rule of m3 in loft.