Project Appraisal and Business Cases: What the Irish Public Spending Code Says

In Ireland, the Public Spending Code sets rules and procedures for public spending, and its capital appraisal guidelines are being replaced by a set of guidance called the Infrastructure Guidelines. This post explains what the official gov.ie pages say about project appraisal and business cases, and where private-sector teams might borrow the ideas. The Code applies to public spending, so anything we say about using it elsewhere is our own suggestion and is labelled as such. If you want a technique for valuing flexibility in investment decisions, see our explainer on real options and investment appraisal.

What the Public Spending Code is

According to the gov.ie page for the Public Spending Code, the Code sets rules and procedures for public spending, with the aim that "the best possible value for money is obtained whenever public money is being spent or invested". The page is a hub of linked guidance, and says the economic appraisal parameters should be used by government departments and State agencies undertaking economic appraisals. It records that the Code was notified to departments in September 2013, updated in July 2019, and followed by a guide published in December 2019. The page shows no "published" or "last updated" date of its own.

The same page records two later changes. A November 2021 circular updated external assurance guidelines for major projects, and Circular 06/2023, issued in March 2023, changed thresholds and requirements for major projects. It also states that Infrastructure Guidelines would replace the Code's capital appraisal guidelines.

Where capital appraisal sits now: the Infrastructure Guidelines

The gov.ie Infrastructure Guidelines collection says the guidelines are value for money guidelines for the evaluation, planning and management of public investment projects. They replace the Public Spending Code's capital appraisal guidelines and the capital expenditure requirements in the December 2019 guide. Guidance on current expenditure sits under Government Accounting instead.

On scope, the page says the arrangements apply to all public bodies and to all bodies in receipt of Exchequer capital funding. It adds that Government departments and their Accounting Officers must ensure that sector-specific procedures, where needed, align with the Infrastructure Guidelines.

The collection page also records a later update: Circular 08/2026, from February 2026, which changed stage requirements for major projects and raised major-project thresholds in the transport, water and energy sectors. The page does not set out the threshold figures in the text we read, and we do not state any. Because the gov.ie pages carry no last-updated date, check the current collection before relying on any description of the rules, including ours.

The stages and the business case

The collection lists stage guides that, in order, cover:

• Strategic Assessment and Preliminary Business Case
• Project Design, Planning and Procurement Strategy
• Final Business Case
• Implementation Stage
• Post Completion Review and Benefits Realisation

The titles show the shape of the lifecycle: an early, strategic look at whether a project is justified, a preliminary business case, detailed design and procurement planning, a final business case, delivery, and then a review of whether the expected benefits arrived. The gov.ie pages list these guides by title; this guide does not describe the content of each guide.

Appraisal methods and financial analysis

The collection links supporting material on economic and financial appraisal. For economic appraisal it lists an Overview of Appraisal Methods and Techniques, a guide to carrying out a cost benefit analysis (described as an introduction covering aims, principles and the estimation of costs and benefits), central technical references and economic appraisal parameters, and supplementary guidance on changes in greenhouse gas emissions. For financial analysis it lists Financial Appraisal Guidelines and financial analysis templates, with separate versions for proposals under and over 1 million. The page does not state the currency.

A worked example of a departmental framework

The Department of Enterprise, Tourism and Employment published a framework dated December 2025 on expenditure appraisal, business cases and economic appraisal. It is a good illustration of how a department applies the national approach, although it governs that department and its agencies rather than all public bodies. The framework says it is based on the Public Spending Code Infrastructure Guidelines, adapted for the enterprise sector, and that requests for sanction for funding initiatives or schemes should be accompanied by a business case.

It describes two business case stages. The Preliminary Business Case sets out the strategic case, including rationale, objectives, options, financial and economic appraisal, risks, governance and monitoring. The Final Business Case incorporates the completed Preliminary Business Case, includes feedback from internal and DPER reviews, and sets out a preferred option and implementation strategy. On option appraisal, it says the do-nothing or do-minimum option should be considered (describing do-minimum as generally the better benchmark), alongside usually three "do-something" options, and that a high-level multi-criteria analysis should be conducted using a simple scoring mechanism to give an overview of the options. It describes cost benefit analysis as comparing the societal benefits and costs of an initiative. The document excludes infrastructure design and procurement from its own approval gates and says infrastructure projects should follow the Infrastructure Guidelines.

Using these ideas outside the public sector

Our suggestion: a private-sector finance or project team is not bound by the Public Spending Code, but the structure translates well to internal investment proposals. A practical approach is to ask for the following before approving a significant spend:

• Objectives and rationale: what problem is being solved and why now.
• A genuine baseline: the cost and consequences of doing nothing or doing the minimum.
• A shortlist of options: scored against agreed criteria, so the preferred option is not simply the first idea.
• Costs, benefits and risks: stated clearly, with assumptions written down.
• Governance and monitoring: who approves, who delivers and how success is measured.
• A post-completion review: checking after delivery whether the benefits materialised.

None of this is a legal requirement for private organisations, and it is not a summary of the Code. It borrows the logic of staged business cases. Where a project is large enough to need professional project management, our guide to project management qualifications in Dublin compares the main credentials.

Procurement is a separate question

Appraisal asks whether and what to spend; procurement rules govern how you buy. If you work in a health setting, our article on HSE procurement compliance and public spending rules looks at that side. This guide makes no statement about public procurement legislation.

What the pages do not say

• The gov.ie Public Spending Code and Infrastructure Guidelines pages show no publication or last-updated dates.
• The two pages describe the relationship slightly differently: one says the Infrastructure Guidelines will replace the Code's capital appraisal guidelines, the other says they replace them. Check the current gov.ie position.
• This guide does not describe what each individual stage guide requires.
• We state no spending thresholds, because the pages we read do not give the figures.

Learnsignal's offices are off Baggot Street in Dublin, and we offer in-person training from there. For current details, see our CPD pages.

Frequently asked questions

What is the Public Spending Code?

Per gov.ie, it is a set of rules and procedures for public spending, aiming to obtain the best possible value for money whenever public money is spent or invested. It was notified to departments in 2013 and has been updated since.

Do the Infrastructure Guidelines replace the Public Spending Code?

The gov.ie pages say the Infrastructure Guidelines replace the Code's capital appraisal guidelines and the capital expenditure requirements in the December 2019 guide. Guidance on current expenditure sits under Government Accounting.

Who must follow them?

The Infrastructure Guidelines page says the arrangements apply to all public bodies and all bodies in receipt of Exchequer capital funding.

What is a preliminary business case?

In the Department of Enterprise, Tourism and Employment framework, it is the first stage and sets out the strategic case: rationale, objectives, options, financial and economic appraisal, risks, governance and monitoring. Other bodies may use different templates, so check the guidance for your sector.

If you are preparing a business case for public money, read the current stage guides on gov.ie. If you are borrowing the approach privately, treat it as a discipline rather than a rulebook.