Garden rooms have become a common feature in London homes. Some are used as home offices, others as gyms, studios, workshops or simply somewhere quiet to sit away from the main house.
They can also seem fairly straightforward compared with a full extension. After all, it is only a small building at the bottom of the garden.
But that does not always mean the Party Wall etc. Act 1996 can be ignored.
Whether you need to serve a Party Wall Notice usually depends on where the garden room is being built, how close the work is to your neighbour’s property and, importantly, what type of foundations are being used.
For that reason, it is worth checking the position before the builder starts digging.
Can the Party Wall Act Apply to a Detached Garden Room?
Yes, it can.
A garden room does not have to touch your house or your neighbour’s house for the Party Wall Act to become relevant.
For example, the Act may need to be considered if you are:
- building directly on or close to the boundary;
- carrying out work to an existing shared garden wall;
- building a new wall at the boundary;
- excavating close to your neighbour’s property;
- digging foundations deeper than the neighbouring foundations.
This is where people sometimes get caught out.
A homeowner may quite reasonably think that because the garden room is entirely inside their own garden, there is no Party Wall issue. In reality, the excavation for the foundations can sometimes be the part that triggers the Act.
If you are unsure, it is worth asking a Party Wall Surveyor in London to look at the drawings before work begins.
Building Close to the Garden Boundary
Most London gardens are not particularly wide, so homeowners often want to push a garden room towards one side or right to the back of the plot.
That makes sense because it leaves more usable garden space.
However, if the new building is going right up to the boundary, you need to be clear about exactly where that boundary sits.
If you are proposing to build a new wall at the boundary, the Line of Junction provisions of the Party Wall Act may apply.
There is also a difference between building a wall completely on your own land and building a wall that sits across the boundary line.
These details matter.
You can read more about this in our guide to the Line of Junction Notice.
It is much better to sort this out while looking at the plans than when the bricklayer is already on site.
The Foundations Are Often the Important Part
The garden room itself may be small, but the foundations may not be.
Some modern timber garden rooms are relatively lightweight and use shallow foundations or ground screws. Others, particularly brick-built rooms, insulated offices or larger structures, may need more substantial foundations.
The depth and position of those foundations should be checked against neighbouring buildings.
This becomes especially relevant where your neighbour has a rear extension, conservatory, garage or another garden building positioned close to the boundary.
If your excavation falls within the distances covered by the Party Wall Act and goes deeper than the neighbouring foundations, a notice may be required.
That is why it is difficult to give a simple answer based only on the size of the garden room.
Two almost identical garden rooms could have completely different Party Wall requirements simply because the neighbouring properties are arranged differently.
What If There Is Already a Brick Garden Wall?
Existing garden walls can cause another area of confusion.
A brick wall sitting on the boundary between two properties may be a shared party fence wall.
If your plans involve cutting into it, raising it, rebuilding it or demolishing part of it, the Party Wall Act may need to be considered.
A timber fence is generally a different matter.
The difficulty is that homeowners do not always know whether an old brick wall belongs to them, belongs to the neighbour or is genuinely shared.
Older London properties can be particularly difficult because the wall may have been there for decades and the original boundary information may not be obvious.
If the garden room design relies on an existing wall, check its status before work starts.
When Should the Party Wall Notice Be Served?
If your proposed work does fall within the Party Wall Act, the notice should be dealt with before the relevant building work begins.
Waiting until excavation has started is rarely a good idea.
A notice gives the adjoining owner formal details of what you are proposing and allows them to respond.
The correct notice will depend on the work being carried out.
Our guide on how to legally serve a Party Wall Notice explains the process in more detail.
Many neighbours are perfectly happy to consent once they understand what is being built and how the work will be carried out.
Others may want more information about the foundations or protection of their property before agreeing.
Both responses are fairly normal.
What Happens If Your Neighbour Does Not Agree?
A neighbour disagreeing with the notice does not automatically mean that your garden room cannot go ahead.
Where a formal dispute arises under the Act, surveyors can be appointed to deal with the Party Wall matters.
In some cases, both owners agree to use a single Agreed Surveyor.
The surveyor will normally review the proposed work and can prepare a Party Wall Award setting out how the works should be carried out.
The Award may cover matters such as working hours, access, protection and the way the Party Wall work is undertaken.
There is also a procedure to follow if the neighbour simply does not reply.
You should not assume that no response means consent.
Our guide explaining what happens if a neighbour ignores a Party Wall Notice covers that situation.
A Schedule of Condition Can Be Worth Having
Even a relatively small project can lead to concerns about cracks or damage.
Suppose your neighbour already has a hairline crack in the rear wall of their extension. Your garden room is built and, a month later, the crack is noticed.
Without any record of the condition before work started, it can be difficult for either side to say whether it was already there.
A Schedule of Condition helps avoid this problem.
It records the visible condition of the neighbouring property before work begins, usually with photographs and written notes.
It is useful protection for both the building owner and the neighbour.
You can read more about the difference between a Schedule of Condition and a Party Wall Award.
Planning Permission Does Not Replace the Party Wall Process
Another point worth remembering is that planning rules and the Party Wall Act are separate.
Your garden room may fall within permitted development and may not need a planning application.
That does not automatically mean that Party Wall procedures are unnecessary.
Equally, receiving planning approval does not give permission to ignore the Act where it applies.
The same principle applies to extensions, loft conversions and other building work.
If you are planning several improvements at the same time, our guide to checking Party Wall requirements before building work starts is a useful place to start.
Check the Details Before Work Begins
Most garden room projects do not turn into complicated Party Wall matters.
The problems usually come from assuming that a small detached building cannot possibly fall within the Act.
Before construction starts, check three things: the boundary, the position of neighbouring buildings and the proposed foundation depth.
If none of these creates an issue, you can move forward with more confidence.
If the Party Wall Act does apply, dealing with it early is usually far easier than trying to resolve the matter after the builder has started excavating.
If you are planning a garden room, garden office, studio or outbuilding in London, Express Party Wall can review the proposed works and advise whether a Party Wall Notice is likely to be required.