The highs and lows of converting a flat roof into a terrace
need to employ a solicitor but there is probably more chance of a landlord giving permission than an owner-occupier.
Only you can decide if their financial remuneration is worthwhile. However, offering to install a new insulated roof may be an attractive proposition, particularly if you were to also take on the responsibility for ongoing maintenance.
In addition to the visual appearance, ie ensuring that any balustrading is in keeping or appropriate for the style of property, the planners will need to be convinced that the roof terrace will not adversely affect the privacy of surrounding residents. Your neighbours will be particularly concerned about being overlooked from above. I suspect the potential for noise and smells from your proposed BBQ parties will not go unnoticed.
In my experience such planning applications frequently generate a vociferous level of objections so be sure to do everything legitimately. Out of courtesy it is a good idea to discuss your plans with neighbours. They may not support the project but it is much better than them hearing a planning application has already been lodged. Going ahead without the requisite permissions will be costly if the local authority starts enforcement action. It will also be problematical when you come to sell the property as the buyer’s conveyancer will want evidence of the permission.
Once you have overcome the legal obstacles the rest is pretty straightforward. You will require a structural engineer to confirm that the supporting walls are capable of supporting the proposed loading. Make sure you give them an accurate idea as to how many people could be using the space at any one time.
While the foundations may be adequate it is unlikely the existing roof will be strong enough as generally flat roofs are only designed to allow for routine maintenance work. If this is the case additional structural support spanning from the walls is required.
It is also essential to consider drainage as the existing roof will have a gentle fall and gulleys. A low budget solution is to use timber decking. Depending on the method of support, the existing weather-proof surface could then be maintained while also providing a level finished surface.
In the event you are not considering a new solid surface your designer must also give consideration to future maintenance of the roof.
There are specialist design and build firms that will deal with every aspect of the build but this comes at a price. In general it is always more economical to project manage yourself but if you want to avoid the stress then hire an architect who can guide you through the process. One cautionary note however, is to assess exactly how sheltered this area of roof is. It may seem a great idea but there’s little point in spending thousands of pounds on something that can be rarely used due it being too exposed.