If your fireplace is no longer in use, you may be considering removing the chimney breast to open up additional internal space. Then you may also think, might as well tidy up the roof line and get rid of the entire chimney in on go. Pros for removing a chimney stack simultaneously with a chimney breast removal or loft conversion:
1. Maximises roof space – enabling a wider future loft conversion and ensuring no internal obstructions in the loft.
2. Eliminates potential obstacles for new windows in future loft conversions, as there won’t be a stack in the way.
However, it is important to note that removing the chimney stack, even when coupled with the removal of the chimney breast, is not as straightforward as it may seem. If you are fortunate enough to have accommodating neighbours who permit the removal of the entire shared stack, the process becomes slightly smoother. If the reason for the whole stack removal is due to deterioration of the shared stack, the costs are usually split between the neighbours. If the shared stack removal is solely for the benefit of your project, you will likely be covering the entire expense.
The work of removing the entire stack does not come under as a ‘notifiable work’ under the Party Wall etc. Act 1996. However, if this stack removal is carried out alongside or part of other work i.e. a loft conversion that is covered by the Act and is already under deliberation in a Party Wall Award, details of how the Adjoining Owner’s roof will be made good will probably be discussed by the party wall surveyor(s) and included in the Award.
In situations where the Adjoining Owner does not consent to the complete removal of the shared stack, you retain the right to remove your half of the stack, albeit with significant complications. As chimneys protrude out from the roofline, they tend to be more exposed to the elements than other parts of the roof. Only removing half of the stack involves cutting away from and exposing the party wall. These are notifiable works under the Party Wall etc. Act 1996 as the party wall within the stack that was previously concealed, becomes exposed. Consequently, the initial step will be to serve a party wall notice to the Adjoining Owner about your proposed intentions of removing half of the chimney stack. The next layer of complexity centers around ensuring the structural integrity of the remaining half of the shared stack owned by the Adjoining Owner. The new structural chimney stack design must be able to withstand adverse weather conditions. Matters such as weatherproofing the area by inserting lead flashing and access on the Adjoining Owner’s roof whilst carrying out this work will be discussed by the appointed party wall surveyor(s).
In conclusion, if the Building Owner is unable to secure the Adjoining Owner’s agreement for the complete removal of the shed stack, choosing to work around the chimney stack becomes the approach with less hassle.