Renovate, extend or knock down and rebuild an old house in Ireland

Plenty of Irish self-builds start with an old house, not a bare field: a farmhouse that came down the family, a bungalow from the 1970s, or a cottage with a plot attached. The choice is the same each time. You can keep the house and renovate it, add to it, or take it down and build again. Each route changes the planning, tax, grants, finance and insurance, so choose with the numbers in front of you.

Start with a survey

Before you decide, find out what you actually have. Ask a building surveyor, an architect or a structural engineer to look at:

• The structure: cracks, bowing walls, sagging roof lines, rotten timber and the state of the foundations.
• Damp and ventilation: rising damp, penetrating damp and condensation each have a different cure.
• The roof: slates, battens and felt, because a roof replacement is a big cost.
• Services: wiring, plumbing, heating and the wastewater system, which may not meet current standards. The wastewater guide explains what a new system involves.
• Hazards: asbestos in old roofing and lagging, and lead pipes. Removal needs specialists, and the cost can change the whole decision.
• Energy performance: a BER assessment shows where the heat is going, and what an upgrade could achieve.

A survey costs little next to the work it can save. The architect or engineer guide explains who to ask.

Three routes compared

	Renovate	Extend	Knock down and rebuild
Planning	Often exempt for internal work, though not for a protected structure	Exempt within limits, otherwise permission	Permission for demolition and for a new house
Energy standard	Upgrade to what is practical	New part meets current rules, the old part is improved	A new house meets current nearly zero-energy rules
Grants	Vacant Property Refurbishment Grant and SEAI grants may apply	SEAI grants may apply to the existing part	Not eligible for the refurbishment grant; SEAI new-build limits apply
Surprises	Hidden defects	Joins between old and new	Demolition waste, services and site conditions
Time	Varies with the scope	Varies with the scope	Planning plus a full build

Use the table to decide what to ask, not as a verdict. Each house is different.

Planning for each route

Renovation of the inside of a house is often exempt from planning permission, within limits. A protected structure, or a house in an architectural conservation area, has more rules, and works that affect its character may need permission or a declaration. Ask the council.

Extensions have exemption limits that depend on floor area, height and the space left at the back. Beyond them you need permission. The planning permission guide covers the application.

Demolition and rebuild needs permission for the new house, and usually for the demolition as well. Rural areas often apply the same housing policy to a replacement as to a new one, though some plans are kinder to a replacement of a lived-in house. Read the rural housing policy guide and ask the planner before you spend money on drawings.

Grants for an existing house

• Vacant Property Refurbishment Grant. For a house that has been vacant for at least two years and was built before 2008, where you will live or rent it out. It is approved before work starts, and permission to demolish and rebuild a new house is excluded. It pays up to €50,000, or €70,000 if the house is derelict, and only on completion: see our grant guide for the conditions and the cash gap, and apply through your local authority.
• SEAI home energy grants. These are aimed at existing homes and help with measures such as insulation, heat pumps and solar panels. Each has its own conditions. A new house does not qualify, as the SEAI guide for new homes explains.

Grants usually require approval or registration before work starts, so do not order anything until you know.

Cost and VAT

Building work on a house, including renovating, altering and extending, generally carries 13.5% VAT. Materials you buy yourself are generally 23%. The VAT guide explains the exceptions and the two-thirds rule. Include VAT in every estimate you compare.

Add a larger contingency to a renovation than to a new build. You cannot see behind plaster or under floors until the work starts, and surprises are common. The cost guide shows how to build up a budget.

Finance for an old house

A lender’s view of a renovation differs from its view of a new build.

• Some offer a renovation or home improvement loan, or a top-up on your existing mortgage.
• A self-build mortgage may be possible for a major rebuild, paid in stages. The self-build mortgage guide explains how that works.
• Lenders look at the valuation before and after, the builder and contract, and insurance.

An inherited house you own outright can give you equity to borrow against. Ask each lender early.

Insurance for an existing structure

An existing house on a building site is a different risk from a bare plot. Your normal home policy may not cover it once work starts, particularly if it is empty, and the contractor’s insurance may cover their work and not your building. Tell the insurer, and ask what covers the old structure, the works and your liability to visitors and neighbours.

The self-build insurance guide explains the covers for a new build.

When knocking down makes sense

Demolition is worth a hard look when:

• the survey finds structural problems whose repair costs close to the cost of a new house;
• the layout cannot be made to work, for example low ceilings and small rooms that no extension fixes;
• you want a house that meets today’s energy standard and the upgrade of the old one would not get there; or
• the planner confirms that a replacement is acceptable on the site.

Whichever way the sums fall, do not strip out or demolish anything until permission, grant approvals and your insurer’s agreement are in place. Work done early can end a grant claim and complicate a planning application. Keep the house when it is sound, has character you value, or when a grant makes the renovation much cheaper. Talk to the planner before you decide, because the answer on the site may rule one route out.

Questions to settle before you commit

• A surveyor or engineer has looked at the building and given you a written report.
• You have an estimate for each route on the same brief, with VAT.
• The council has said what permission each route needs.
• You know which grants apply, and what must be approved before work starts.
• A lender has told you what it needs.
• The insurer knows the plan, and your cover continues during the works.
• A solicitor or tax adviser has looked at any inheritance or transfer.