If you're considering dividing your flat in two, the first step is to check the title deeds for your property, to ensure that there are no restrictions which would prohibit you from doing so. Your title deeds may contain rights in favour of your neighbours which would restrict what you can do with your flat. If you're planning on renting out one of the properties following division, it's wise to check whether this is permitted under your deeds and the terms of any mortgage over the property. Your solicitor can advise you on the terms of your title deeds.
Planning and building
Provided there are no barriers contained in these, the planning and building implications of division should then be considered. You'll have to obtain planning permission from your local council before carrying out any works. Your neighbours will have an opportunity to make representations about the application for planning permission so it's a good idea to keep them informed of your plans at an early stage to ensure they are aware of your proposals.
A building warrant will also be required - this covers the specific construction works to be carried out to ensure that your renovations conform to current building regulations.
Additional restrictions apply and further consents will likely be needed if the property is a listed building or located in a conservation area. You should speak with your local council about your plans before submitting any applications, in addition to seeking specialist planning and building advice.
Other considerations
Other practical considerations should be taken into account including whether there are clear access routes to both properties and how services will be provided to each property. This could involve installing or re-routing pipes and cables. Again, your title deeds should be examined to ensure that re-routing or removing any pipes/cables won't breach any of your obligations to neighbouring properties.
Finally, I'd recommend taking legal advice before making any decision about splitting your property - it's always better to establish permission before changing anything structurally.
Contributor
Senior Solicitor