Semi D to Flat conversion Project

[Annker]

Hello all, not entirely sure which sub-forum to post this in, many questions to answer but I thought this neck of the forum may be best!

 

I have recently bought a large victorian semi-d in need of significant renovation work. 
I bought the house with ~60% LTV mortgage and the initial plan was to renovate the property to continue its life as a single dwelling house.However since purchasing my conversations with colleagues, estate agents and my own ongoing assessments of the property (I work in construction) is directing me to consider the potential of converting the property into 2x (potentially 3x) self contained 3 bed flats.

For context I have extensive construction work experience in both new build and renovation works in both small scale and large scale development, however I have not much experience in, say the administration, of such a residential conversation project.

I imagine the first steps are to put together a basic appraisal of the project and therefore I'm trying to list the big ticket items that will determine if this scheme is feasible:

1. How will my current residential mortgage lender (HSBC) view my plans.
   1. I have called the broker who arranged my mortgage and he is going to make enquiries with my lender to ask if they would allow the scheme. He said its likely I'll have to refinance. That cost allone may put a stop to the scheme
2. Determining the likelihood of obtaining Planning Permission for the scheme
   1. I am fairly confident that PP would be granted as the attached neighbouring property as converted to flats as is the property on the other side.
3. Determine if there Is a market for converted flats
   1. I had a brief conversation with the EA we purchased the property from and he said he has a few investors who are looking to buy such a scheme in its entirety so there are buyers in the market at least
4. Financial appraisal.
   Even if the conditions above are met obviously the numbers still need to stack. I believe I can cost a regular renovation quite accurately however with little experience of flat conversions I'm trying to think of the big expenses that are particular to this type of project:
   1. Splitting the existing single household utility supplies to serve 2x or 3x self contained units, I imagine this will be a costly but for the scheme it would be necessary expense
   2. Fire safety/regulations
   3. Acoustic performance/regulations

Anyway I would greatly appreciate if any group members can advise on any of the items above, give my pointers, additional items to add to the list, or indeed any offer their experience if they have undertaken a similar scheme:

Thanks for reading!