House Rebuild Cost and Sum Insured: How to Get the Figure Right
The sum insured on a house insurance policy is the cost of rebuilding the house from the ground up, not its market value. The two figures are not the same thing, and the right approach is to insure for the rebuild cost, using the Society of Chartered Surveyors Ireland for current costs. Insure for too little and a claim may be paid in proportion; insure for too much and you pay a higher premium for no extra benefit.
GMIB.ie compares house insurance quotes from a wide panel of insurers, and where the form cannot give a price straight away one of our agents reviews your details and calls you back with the options. The home quote form is at the foot of this page.
How to work out your rebuild cost with the SCSI calculator
Check the calculator applies to your house. The SCSI rates are for estate-type houses built in Ireland since the 1960s. They do not cover one-off houses in the countryside, period houses, houses with more than three storeys or a basement, or apartments. For those, get a rebuild cost estimate from a chartered quantity surveyor or building surveyor; the SCSI publishes a directory of providers. Apartment owners should ask the management company about the block policy.
Measure the floor area. The SCSI method is to measure the internal area of each floor to the internal finish of the perimeter or party walls, ignoring skirting boards, and add the floors together. On most two-storey houses the upper floor matches the ground floor; if it does not, measure each floor separately.
Choose the house type and region. The calculator gives rates by house type and by region. If your house sits between two regions, take the higher rate, or asking for a quote on both figures.
Add what the base figure leaves out. The SCSI figures are a minimum base for a standard specification. It says to add for a garage, outbuildings such as a shed, studio or home office, better-than-average kitchens and wardrobes, high-specification bathrooms, high boundary walls and other finishes above the standard specification.
Know what is already in the figure. The SCSI rates are calculated on a total loss and allow for demolition, rebuilding to current building regulations, the professional fees of building surveyors, architects, engineers and quantity surveyors, certification under the Building Control (Amendment) Regulations 2014, VAT, and a path, driveway, grass and fencing around the house. Contents such as carpets, curtains, furniture and appliances are not included; they belong under contents cover. The SCSI also points out that a rebuild cost assessment is not a valuation, which is a separate matter.
Underinsurance, indexation and when to review the figure
What underinsurance costs you. The SCSI explains that where the sum insured is only three-quarters of the full reinstatement cost, the insurer may pay only three-quarters of a claim, whether the claim is for a partial repair or a total loss, and the owner provides the balance. The Competition and Consumer Protection Commission (CCPC), the State’s consumer watchdog, gives the same proportion in its own example and says the main reason for underinsurance is rising building costs, mainly higher prices for materials.
Indexation helps but does not replace a check. The CCPC notes that many insurers use indexation, increasing the sum insured each year in line with inflation. The CCPC still says to check buildings and contents cover every year, especially at renewal, and the SCSI says insurers recommend re-assessing cover every year against current average rebuilding costs.
When to revisit the figure. The triggers are: an extension or renovation, including an attic conversion or a home office, a period of high inflation or rising building costs, new valuables, moving house, or a policy that lapsed. The SCSI guide behind the calculator is dated, with the current edition published on 4 November 2025, so a figure worked out on an older edition is worth re-running.
Mortgages and apartments. Home insurance is not compulsory, but a mortgage lender may require buildings insurance to cover the rebuild cost. The CCPC notes that where you pay management fees, buildings insurance is usually covered within them, and says an apartment owner should still consider their own contents cover.
Using the figure when you compare quotes. Give each insurer the same rebuild cost so the prices describe the same policy. Our guide to comparing house insurance in Ireland covers the rest of the comparison, and our house insurance page explains buildings and contents cover. To talk through a figure, call 0818 92 92 42, Monday to Friday, 9am to 5.30pm.
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Market value includes the site and the location; rebuild cost is only what it would take to demolish and rebuild the house to current regulations, including professional fees and VAT. Insure for the rebuild cost, not the market value; the SCSI calculator is built for that figure.
No. A unique or period property should be costed by an appropriately qualified professional such as a local chartered quantity surveyor, and it publishes a directory of rebuild cost estimate providers. The section above lists the house types the calculator does not cover.
Yes. The SCSI rates allow for VAT at the rates current when the guide was published and for the fees of building surveyors, architects, engineers and quantity surveyors, including certification under the Building Control (Amendment) Regulations 2014. What you add yourself is a garage, outbuildings and any fittings above the standard specification.
Yes. Indexation is on the CCPC’s list of ways to avoid underinsurance, but so is reviewing your cover every year and updating it after an extension or renovation. Re-run the SCSI calculator at renewal and compare its figure with the indexed sum insured on your renewal notice.
No. The sum insured for buildings covers the structure and permanent fittings. Contents such as carpets, curtains, furniture and appliances are insured separately; insure them for the full cost of replacing everything.
