Granny flat costs: build a complete project budget

A useful granny flat budget separates the home price from the work needed on your particular property. Nua Living’s home prices include design, build and project management. Site works, utility connections and professional fees are excluded; the written project quote needs to identify these separately.

Start with a VAT-inclusive home price

The 33 m² 1 Bed Granny Flat is €93,900 + VAT (€106,577 incl. 13.5% VAT). The 45 m² 1 or 2 Bed Granny Flat is €126,500 + VAT (€143,578 incl. 13.5% VAT). VAT totals are rounded to the nearest euro. These are home prices, not a total installed project budget.

Use the current model and price list for the full range and specification. The Garden Studio is a non-habitable garden room, so it is not an entry-price dwelling. Revenue’s construction-services guidance explains the general VAT treatment; your written quote should state the rate and scope of the actual supply.

Questions that make site costs clearer

• Access: how will materials, equipment and concrete reach the rear garden? What protection and reinstatement are needed?
• Ground and foundations: what investigation and foundation design are included, and what happens if unsuitable ground is found?
• Services: where are the existing water, electricity and wastewater routes, and what capacity checks are needed?
• Levels and drainage: will paths, retaining work or drainage changes be needed?
• Professional work: who provides surveys, design certification, inspection and completion documents?

Ask for an itemised scope after the site assessment. We do not publish a generic allowance for these items because it would imply knowledge of ground, routes and professional requirements we have not inspected.

Planning affects the scope too

Condition 7 of Class 3A sets a 32–45 m² external-footprint band, counted together with earlier Class 3 garden structures. S.I. No. 340/2026, Class 3A.

A 48 m² home is outside the Class 3A size band and needs planning permission. A smaller home still needs the full site and use assessment. Review the planning conditions and ask which drawings and application work are included if permission is required.

A Class 3A auxiliary dwelling follows the normal Building Control process, including a Commencement Notice, design and assigned certifiers, a competent builder and a Certificate of Compliance on Completion. Department Circular BC07-2026.

The planning notification and Building Control submission are separate. Lodge the BCMS Commencement Notice 14–28 days before starting work; allow at least 14 days after the council notification too. Start with the BCMS submission, then the council notification, so the periods can run together. Check the pre-start paperwork guide for current council forms and professional responsibilities.

What to get in writing before committing

• The model, layout, specification and VAT-inclusive amount.
• Every inclusion, exclusion and responsibility for site work, services and professional appointments.
• How unknown conditions or changes are priced and authorised.
• The payment stages, structural warranty terms and programme for your project.
• The documents required at handover and who arranges them.

A quote should make the whole project understandable. A fixed building price does not turn excluded work into included work. Our build journey helps you ask these questions at the appropriate stage.

Primestructures carries out the on-site ICF structural build in 5–10 days once foundations are ready. This is a structural stage, not a move-in promise: design, site preparation, statutory processes, fit-out and service connections need their own programme.

Discuss your garden

Ask us to review your garden and explain the home price and separate project costs. Request a callback and a free, no-obligation site visit. We can discuss site eligibility and prepare a written scope and quote.