Garage conversion questions, answered

A garage conversion in Ireland costs €15,000 to €25,000 at a standard finish, €20,000 to €30,000 mid-range and €30,000 to €45,000 at a high spec, VAT included. Dublin and the commuter counties run up to a fifth higher. A shower room adds €4,000 to €8,000 at a basic finish or €10,000 to €18,000 mid-range, and opening it into the house with a steel beam €2,000 to €4,000.

About €30,000 to €48,000 mid-range at national prices, the conversion plus a shower room fit-out.

An attached garage at the side or back of the house can be converted without planning permission under Class 1, as long as the garage isn't made bigger and the conversion, added to every extension built since 1 October 1964, stays within 45 m². A garage at the front, one built into the house facing the road, or a detached garage isn't covered by Class 1: get a section 5 declaration (€80) from the council first, and expect to apply for permission to make a detached garage somewhere to sleep or live.

Not clearly. Class 1 names garages at the side or rear. Ask the council for a section 5 declaration (€80).

For an office, gym or playroom that goes with the house, often yes. For a bedroom or somewhere to live, no.

Every garage conversion has to meet the Building Regulations, exempt from planning or not: walls, floor and roof insulated to today's standard, a damp-proof floor, ventilation, mains-wired smoke alarms and, in a bedroom, a window big enough to climb out of. An exempt conversion of 45 m² or less needs no commencement notice.

Yes: at least 0.33 m² of clear opening, no less than 450 mm wide or high, the bottom no more than 1,100 mm above the floor.

Not for an exempt conversion of 45 m² or less. With planning permission or over 45 m², yes: 14 to 28 days before work starts.

Most single garages take 6 to 10 weeks on site, once the drawings and the price are agreed. A section 5 declaration or a planning application comes before that: allow about 12 weeks for planning permission.

Converting the garage costs €20,000 to €30,000 at a mid-range finish. A 20 m² single-storey extension at the back, with drawings and engineer's fees, comes to €42,000 to €54,000, roughly twice as much, because the foundations, walls and roof of a garage are already built.

Yes. The wall between the store and the new room then needs fire resistance, with a self-closing fire door if there is a door through it.

13.5% on the building work and on fixtures the builder supplies and fits. 23% on furniture, appliances and professional fees.

Not a general one. Where a room is needed because of a disability, the Housing Adaptation Grant can pay up to €40,000.

A single vetted builder for your area receives your answers with our estimate and calls to arrange a look at the garage. The written price comes after that, and it's yours to accept or turn down.