If you need more space at home in Ireland, two options come up again and again: a house extension or a log cabin in the garden. Both add usable space to your property. But the costs, timelines, planning requirements, and long-term value differ dramatically.

This guide gives you a straight, honest comparison so you can make the right decision for your budget and situation.

The Short Answer

A log cabin costs 3–10x less than a block-built house extension, can be installed in days rather than months, and in most cases requires no planning permission. A house extension is permanently attached to your home and may add more resale value in certain markets – but it comes at a significant cost and disruption.

Neither option is universally better. The right choice depends on what you need the space for.

Cost Comparison: Log Cabin vs House Extension Ireland

Cost ItemLog CabinHouse Extension
Structure / build costFrom €8,100–€39,000+€1,500–€2,500 per m²
Typical 20m² space€8,100–€15,000€30,000–€50,000
Foundation / groundworks€800–€3,000€5,000–€15,000
Planning permissionUsually not required (under 25m²)Often required (varies by size)
Architect / design feesNot required€2,000–€6,000
Build time2–5 days assembly8–20 weeks
Disruption to homeNoneSignificant (dust, noise, access)
VATIncluded in price23% VAT on labour and materials

Example: A 20m² home office extension in Dublin typically costs €40,000–€55,000 fully finished. The equivalent log cabin – our IR-017 20m² garden office – costs from €5,500 for the structure, with a total installed cost of €8,000–€14,000. That’s a saving of €26,000–€47,000 for the same usable floor area.

Planning Permission: Log Cabin vs House Extension

Log Cabin

In most cases, a garden log cabin under 25m² used as a home office, hobby room, or garden room does not require planning permission in Ireland, provided it is:

  • Located to the rear of the house
  • Not exceeding 25m² in floor area
  • Not used as a separate dwelling or for sleeping
  • Not extending beyond the side of the main house

Read our full Planning Permission Guide for Log Cabins in Ireland for a detailed breakdown.

House Extension

Single-storey rear extensions under 40m² are often exempt from planning permission under Irish regulations – but only if your previous exemption allowance hasn’t already been used. Any extension that exceeds 40m² at the rear, is a first-floor addition, or affects the front of the house will require full planning permission, adding 3–6 months to the timeline and €2,000–€5,000 in fees.

Build Time: Log Cabin vs House Extension

StageLog CabinHouse Extension
Design / planningChoose a model online – 1 dayArchitect drawings – 4–8 weeks
Planning permission (if needed)Usually not required8–12 weeks
Groundworks / foundations1–3 days2–4 weeks
Build / assembly2–5 days6–14 weeks
Internal fit-out1–2 weeks (optional)4–8 weeks
Total typical timeline2–6 weeks from order5–12 months from design

If you need extra space quickly – for a new baby, a remote working setup, or an elderly parent moving in – a log cabin is the only option that can realistically be ready within a month.

Which Adds More Value to Your Property?

This is the most common question – and the honest answer is: it depends on how you measure it.

House Extension

  • Permanently increases the official floor area of your home.
  • Adds directly to the property’s square footage for valuation purposes.
  • A well-built 20m² extension can add €30,000–€60,000 to a property’s market value in Dublin and other urban areas.
  • ROI varies – in some cases you recover only 50–70% of build cost in added value.

Log Cabin

  • Does not increase the official floor area of the main house.
  • Estate agents consistently report that a quality garden cabin improves saleability and can add €5,000–€20,000 to a property’s appeal.
  • At a fraction of the cost, the ROI is often higher in percentage terms.
  • A garden office or annexe cabin is a strong selling point in today’s market.

Read more: Why a Log Cabin is the Perfect Investment for Your Property.

Which Is Better for a Home Office?

A log cabin wins here – and it’s not close. A dedicated garden office gives you physical separation from home life, no disruption to the household, and a professional space for meetings. Our most popular model is the IR-017 – 20m² Garden Office Cabin from €5,500. Read our full Log Cabin Home Office Ireland guide.

Which Is Better for a Granny Annexe?

A log cabin is more practical and affordable. A self-contained timber annexe costs €12,000–€30,000 fully installed vs €60,000–€120,000 for a block-built extension. See our Granny Annexe range and read the full Granny Annexe Ireland 2026 guide.

Which Is Better for an Extra Bedroom?

A house extension has an advantage if you need a permanent sleeping room connected to your home. However, for a separate guest bedroom or rental unit, a log cabin is a strong option – particularly our IR-004 two-storey cabin. Read more: 2 Bedroom Log Cabin Ireland – Complete Guide.

Disruption: The Factor People Underestimate

A house extension means living on a building site for 2–5 months with dust, noise, and tradespeople in and out daily. A log cabin assembly takes 2–5 days and happens entirely outside the main house.

Frequently Asked Questions

Can a log cabin be used as a permanent living space in Ireland?
Yes, with planning permission and appropriate insulation. Read our guide: Can You Live Permanently in a Log Cabin in Ireland?

Do I need planning permission for a log cabin in Ireland?
In most cases, no – if the cabin is under 25m², positioned to the rear, and used for non-residential purposes. Read our full Planning Permission Guide.

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