Adding a Modular Garden Room to Your Home Insurance in Ireland: What You Need to Know
Garden rooms have become one of the most popular home upgrades in Ireland. Whether it’s a home office at the end of the lawn, a gym, a studio, or simply extra living space, a modular garden room is a relatively fast and affordable way to add square footage without the disruption of a full extension. With the new easing of restrictions on planning permission many people are taking a fresh interest in installing a modular home on their property. But there’s one step homeowners often overlook once the build is finished: updating their home insurance.
A garden room isn’t just a nice-to-have addition sitting quietly in the background of your property – from an insurer’s point of view, it’s a change to your risk profile. Here’s what to think about before and after you build one, including a risk that catches many people off guard: subsidence.
Why You Need to Tell Your Insurer
Most standard Irish home insurance policies are built around your buildings cover (the structure itself) and your contents cover (what’s inside). Garden structures like sheds and greenhouses are often picked up automatically under buildings cover, but a modular garden room is usually a bigger, more valuable structure – likely insulated, wired for electricity, plumbed and fitted out like a proper room. That takes it beyond what a policy typically assumes when it was first set up.
Insurers generally expect to be told about:
- The size and value of the structure – it increases your overall rebuild cost
- How it’s built – modular construction comes in a variety of forms and uses different foundations. This can all make a difference
- How it will be used – a big up-coming use for garden rooms will be as apartments or granny flats now that planning restrictions have been listed. But a gym or a client facing office will likely affect your insurance
- What’s kept inside it – equipment, electronics, or furniture will need to be added to your contents cover to ensure you aren’t underinsured should you need to make a claim.
Skipping this step doesn’t necessarily mean you have no cover at all, but it does create real risk: if you ever need to claim for storm damage, fire, theft, or structural movement, an insurer can question or reduce a payout – or reject it outright – on the basis that they weren’t given an accurate picture of the property.
The Subsidence Angle Most People Don’t Think About
Subsidence is ground movement beneath a structure, usually caused by shrinking clay soil during dry periods, nearby tree roots drawing moisture from the ground, or water escaping from damaged drains and washing away the soil that supports foundations. It’s a well-known risk for older Irish homes, particularly in areas with clay-rich soil such as parts of Dublin, Cork, and Meath, but it’s increasingly relevant to modular construction too, for a few reasons:
Lightweight foundations behave differently to your main house. Many modular garden rooms are installed on ground screws, timber sub-frames, or paving-slab bases rather than a full concrete raft foundation. These are quicker and cheaper to install, and they work well in the right ground conditions – but on soft, clay-heavy, or poorly draining soil, a lighter foundation may be more prone to movement than the deeper foundations under your main house.
New structures can change how water moves around your garden. Excavation, added hardstanding, or a new base can alter local drainage patterns. If rainwater starts pooling near your home’s existing foundations instead of draining away as it did before, that can, over time, increase the risk of ground movement close to the house itself – not just under the new room.
A poorly chosen foundation for the soil type is a common root cause. Ground screws are excellent for many gardens, but they’re not automatically suitable everywhere – soft or peaty ground, may call for a different approach. Getting a proper site assessment before the build, rather than assuming one foundation type suits every garden, is one of the simplest ways to reduce risk later.
None of this means a garden room will cause subsidence. Most are built and installed without any issue. But because subsidence claims in Ireland tend to be slow, closely investigated, and subject to a higher excess than other claim types, it’s worth insurers knowing exactly what’s been added to your property and how it was built – it directly affects how confidently they can assess and price that risk. There is a risk that subsidence won’t be covered on your policy at all when it comes to modular construction.
When You Might Need Non-Standard Home Insurance
Most homeowners who add a garden room will simply update their existing standard policy and carry on as before. But there’s a subset of cases where a mainstream insurer may decline to cover the garden room – or the property as a whole – and you’ll need to look at non-standard (sometimes called “specialist”) home insurance instead.
This isn’t a reflection on the quality of your build. Non-standard simply means the property falls outside the risk assumptions a general insurer’s standard rate card is built around, so it needs an underwriter willing to assess it individually. A few triggers are particularly relevant when a garden room is involved:
- An existing subsidence history. If your home has previously experienced subsidence, heave, or landslip – even somewhere unrelated to the garden room, or years in the past – many mainstream insurers will decline to offer cover, or will impose significant restrictions, on the whole property. This is especially likely if the property was ever underpinned.
- Non-standard construction methods. Timber frame, modular builds, structural insulated panels (SIPs), and steel-frame structures can sit outside a standard insurer’s usual criteria, even when they’re well-built and fully certified. If the garden room’s construction is unusual enough to change how the wider property gets classified, it’s worth checking with your insurer before you commit to a build method.
- Business or rental use. A garden room used as an Airbnb unit, a rented annexe, or a space for a client-facing business – a therapy room, a salon, a creche – often falls outside what a standard home policy assumes. Insurers may treat this as a change of use requiring specialist or commercial cover, and understating the use to keep premiums down is a fast way to have a future claim refused.
- Location-based risk. If your property is already in an area associated with flooding, landslip, or subsidence, adding any new structure can prompt an insurer to reassess the whole policy rather than simply add the extension to your existing terms.
If you end up in this position, we can help, since we have access to insurers who underwrite non-standard risks individually rather than relying solely on a standard rate card. You should expect to provide more supporting documentation than a typical application – a structural survey or engineer’s report, evidence of any remediation works such as past subsidence repairs, and details of the garden room’s construction and foundation type. Also bear in mind premiums for non-standard cover tend to run higher than standard policies, but non-standard doesn’t mean uninsurable – it just means the risk needs a closer look before someone will price it.
Steps to Take Before and After Building
- Talk to your insurer or broker before construction starts. Give them the size, estimated value, foundation type, and intended use of the garden room. Ask directly whether it will be covered under your existing buildings cover or whether you need to add it as a specified structure.
- Ask about subsidence cover specifically. Confirm whether subsidence is included as standard, what the excess is, and whether adding a new structure affects those terms in any way. Often this won’t be covered but it’s important you know where you stand before you start building.
- Keep your paperwork. Retain the contractor’s specification, foundation details, and any site survey or engineer’s report. If a claim ever arises, this evidence helps show the structure was installed appropriately for the ground conditions.
- Choose your foundation with the soil in mind, not just the budget. A reputable installer should be able to tell you whether your garden’s soil type is suited to ground screws, concrete piers, or a full concrete base – and should flag it if conditions are challenging.
- Stay on top of drainage. Keep gutters, downpipes, and any drainage around both the garden room and the main house clear and in good repair, and be mindful of planting large, thirsty trees close to either structure.
- Update your contents cover. If the garden room houses expensive equipment – a home office setup, gym equipment, or musical instruments – check the single-item or overall contents limits, as garden buildings sometimes have lower default limits than the main house. This is doubly true if you have built a modular apartment rather than a garden room extension.
The Bottom Line
A modular garden room can add real financial value and everyday enjoyment to a home, but it also changes what your insurer needs to know about your property. Notifying them isn’t just a box-ticking exercise – it’s what keeps your cover valid and ensures that if something does go wrong, from storm damage to the slower-moving risk of subsidence, you’re not left arguing over the small print at the worst possible time.
