Party Wall Advice - Building an Extension Wall Astride the Boundary
It may seem counter-intuitive that the Party Wall Act should allow a building owner to construct a wall for his own use (e.g. in order to enclose on his ground floor extension) partly on his neighbour's land.
If you are an adjoining owner reading this, you my be pleased to hear that the Act only allows it in only very specific situations and then only with certain caveats.
It is worth noting that even where the building owner does not have the right to build a wall straddling the boundary line, there is nothing to stop him from sending the adjoining owner a notice requesting permission to build such a wall. Where the right does not exist, the adjoining owner need not even reply as there is deemed dissent.
So when, you may ask, does the building owner have the right to construct such a wall (following notice) even with the dissent of the adjoining owner?
The answer is - 'where there was a pre-existing wall in that position'.
For example, there is an existing garden wall separating two gardens and this wall is built straddling the boundary line, the building owner, therefore has the right (after serving a Section 1:2 notice) to remove and rebuild the wall in the same position, i.e. half on his neighbour's land. The end result is that his ground floor extension flank wall can legitimately be sat across the boundary line.
Two caveats are as follows:
Imagine a typical garden wall of circa 200 mm width, built say 100 mm on the building owner's land and 100 mm on his neighbour's land, it does not follow that the building owner may now erect a thicker wall e.g. a circa 360 mm wide cavity wall straddling the boundary line i.e. 180 mm of which would sit on his neigbour's land. He would have to locate the wall with 180 mm of its width on his own land with the remaining 100 mm on his neighbour's land. The end result is that the new flank wall of the extension would occupy no more land of his neighbour's than the original boundary wall occupied.
Another caveat, is that the flank wall built straddling the boundary is deemed a shared wall such that his neighbour may at some later point enclose on it. You may ask, can the neighbour enclose on it for free, and the answer would be 'strictly speaking, no'.
However, in the freewheeling world of neighbourly disputes and negotiations, what may well happen is that a building owner wishes to build a ground floor extension as wide as he can get away with. His neigbour though, shows no inclination to allow the flank wall to straddle the boundary line. There is no pre-existing garden wall straddling the boundary, hence, our ambition building owner is left with the prospect of having to make do with an extension entirely occupying his own land and none of his neighbour's.
Following the neighbour's rejection of his proposal our building owner goes home and practises a pitch in front of the bathroom mirror until he is word perfect. The gist of the pitch is that should the adjoining owner be so indulgent as to allow the flank wall of the extension to cross the boundary line with half its thickness on the adjoining owner's land, the building owner will ensure that the Award specifically states that the adjoining owner may at some future time enclose on the wall for free.
From my experience, such approaches often work and may even be a selling point when the adjoining owner comes to sell the house. But the adjoining owner would do well to bear in mind the following points before giving permission.
1. The height of the proposed flank wall and the width of the garden: These two can conspire to create of hemmed-in feeling and can feel intrusive. In the picture below the higher wall to the right is actually situated wholly on the next door neighbour's land. But I had to measure up to confirm this. The effect of this high wall and narrow garden is to make the garden to the left feel smaller.
2. Once such a wall is agreed to, there is no requirement under the Party Wall Act for the building owner to consult the adjoining owner should he wish to extend the wall upwards at a later point e.g. to add another floor, at which point the proximity of the wall may start to make itself felt to the adjoining owner.
3. Enclosing on a shared wall at some later point is all good and well but noise can easily be transmitted through such a wall. Hence, the adjoining owner should make any such permission conditional on soundproofing being added at the time of the wall's construction and at the building owner's expense.
But say our adjoining owner has indeed granted permission he does have a perk to look forward to. Apart from the fact that he may enclose enclose on the existing wall, thus obviating the need to incur the cost, he also benefits that when it comes time for him to enclose on the shared wall, he will likewise gain the benefit of space maximisation and his extension will be wider than it would have been were he to have built the flank wall entirely on his own land.
If you are an adjoining owner reading this, you my be pleased to hear that the Act only allows it in only very specific situations and then only with certain caveats.
It is worth noting that even where the building owner does not have the right to build a wall straddling the boundary line, there is nothing to stop him from sending the adjoining owner a notice requesting permission to build such a wall. Where the right does not exist, the adjoining owner need not even reply as there is deemed dissent.
So when, you may ask, does the building owner have the right to construct such a wall (following notice) even with the dissent of the adjoining owner?
The answer is - 'where there was a pre-existing wall in that position'.
For example, there is an existing garden wall separating two gardens and this wall is built straddling the boundary line, the building owner, therefore has the right (after serving a Section 1:2 notice) to remove and rebuild the wall in the same position, i.e. half on his neighbour's land. The end result is that his ground floor extension flank wall can legitimately be sat across the boundary line.
Two caveats are as follows:
Imagine a typical garden wall of circa 200 mm width, built say 100 mm on the building owner's land and 100 mm on his neighbour's land, it does not follow that the building owner may now erect a thicker wall e.g. a circa 360 mm wide cavity wall straddling the boundary line i.e. 180 mm of which would sit on his neigbour's land. He would have to locate the wall with 180 mm of its width on his own land with the remaining 100 mm on his neighbour's land. The end result is that the new flank wall of the extension would occupy no more land of his neighbour's than the original boundary wall occupied.
Another caveat, is that the flank wall built straddling the boundary is deemed a shared wall such that his neighbour may at some later point enclose on it. You may ask, can the neighbour enclose on it for free, and the answer would be 'strictly speaking, no'.
However, in the freewheeling world of neighbourly disputes and negotiations, what may well happen is that a building owner wishes to build a ground floor extension as wide as he can get away with. His neigbour though, shows no inclination to allow the flank wall to straddle the boundary line. There is no pre-existing garden wall straddling the boundary, hence, our ambition building owner is left with the prospect of having to make do with an extension entirely occupying his own land and none of his neighbour's.
Following the neighbour's rejection of his proposal our building owner goes home and practises a pitch in front of the bathroom mirror until he is word perfect. The gist of the pitch is that should the adjoining owner be so indulgent as to allow the flank wall of the extension to cross the boundary line with half its thickness on the adjoining owner's land, the building owner will ensure that the Award specifically states that the adjoining owner may at some future time enclose on the wall for free.
From my experience, such approaches often work and may even be a selling point when the adjoining owner comes to sell the house. But the adjoining owner would do well to bear in mind the following points before giving permission.
1. The height of the proposed flank wall and the width of the garden: These two can conspire to create of hemmed-in feeling and can feel intrusive. In the picture below the higher wall to the right is actually situated wholly on the next door neighbour's land. But I had to measure up to confirm this. The effect of this high wall and narrow garden is to make the garden to the left feel smaller.
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| The neighbour to the right built his wall straddling the boundary line yes / no? |
2. Once such a wall is agreed to, there is no requirement under the Party Wall Act for the building owner to consult the adjoining owner should he wish to extend the wall upwards at a later point e.g. to add another floor, at which point the proximity of the wall may start to make itself felt to the adjoining owner.
3. Enclosing on a shared wall at some later point is all good and well but noise can easily be transmitted through such a wall. Hence, the adjoining owner should make any such permission conditional on soundproofing being added at the time of the wall's construction and at the building owner's expense.
But say our adjoining owner has indeed granted permission he does have a perk to look forward to. Apart from the fact that he may enclose enclose on the existing wall, thus obviating the need to incur the cost, he also benefits that when it comes time for him to enclose on the shared wall, he will likewise gain the benefit of space maximisation and his extension will be wider than it would have been were he to have built the flank wall entirely on his own land.
BH Party Wall Surveyors
is a London-based party wall surveying company offering advice and
party wall services to building owners and adjoining owners. Readers
should always take their own professional advice and not rely on the
information provided here particularly given that no two situations are
identical. www.bhpwsurveyors.co.uk
