One claim featured prominently in the debate surrounding the new legislation: that Ireland operates a “plan-led” planning system.

In reality, there is little meaningful sense in which this claim can be sustained.

Ireland certainly has development plans. Local authorities produce substantial documents every six years outlining land uses, housing strategy, infrastructure objectives and environmental protections. But the fact these documents are called plans does not mean they function as plans in the ordinary sense of the word.

In practice, they contain policies on matters such as density, building height, heritage protection and design quality, but they rarely establish binding spatial rules.

A development plan will often state increased building height “may be appropriate” in certain areas, or higher densities “should be encouraged” near transport corridors. What it seldom does is define, in explicit terms, the precise form of development permitted on a particular site.

It is this absence of precision that creates difficulty.

When planning operates through policy rather than rule, interpretation becomes the system’s defining characteristic. Applicants interpret policies in ways that support their proposals. Planning authorities often take a different view. An Coimisiún Pleanála may reach another again.

The result is that outcomes become difficult to predict.

The situation is further complicated by the layered nature of Irish planning policy. Local development plans must operate alongside regional spatial strategies, national policy frameworks and ministerial guidelines. Each layer must be balanced and interpreted.

To understand what a genuinely plan-led system looks like in practice, it is useful to look elsewhere.

In New York City, development is governed by a detailed document known as the Zoning Resolution. This document specifies, with mathematical precision, what can be built on each site within the city boundary — how large a building may be, how many floors it can contain, how far it must stand back from the street and what uses are permitted.

If a proposal complies with these rules, approval is granted “as of right”.

In practical terms, this means if you were considering buying a site — imagine you had just spotted a parcel of land for sale outside Cork — a quick review of the zoning provisions would tell you almost immediately what could be built there. The answer would not depend on interpretation or negotiation. It would already be written into the plan.

New York is, of course, a vast and complex city, so the process is not always quite so simple. Buildings in landmark districts are subject to design review, and large or unusual projects may trigger additional procedures. But for the majority of typical developments, the system operates with striking clarity.

In many cases the process moves even more quickly. Through a mechanism known as professional certification, an architect or engineer may declare that a proposal complies with the zoning rules without the need for detailed review by city officials. Where that certification is accepted, the project proceeds directly to permitting.

Germany operates in a similarly structured way. Local plans known as Bebauungspläne establish binding development parameters at a detailed spatial scale. Height limits, building lines and permitted uses are defined in advance. If a proposal fits the plan, permission follows.

These systems differ politically and culturally from each other, but they share a central strength: clarity.

Ireland’s system, by contrast, leaves much to interpretation. The word “appropriate” appears repeatedly in planning documents and decisions. It sounds reasonable — suggesting flexibility and compromise — but in practice it is too elastic to be useful.

Once a debate turns on whether something is “appropriate”, it is unlikely ever to be settled.

The consequences are familiar to anyone who has dealt with the Irish planning system. Applicants cannot confidently predict outcomes before investing in design work. Local authorities struggle to ensure consistency. Communities experience development not as the implementation of an agreed spatial vision but as a sequence of ad hoc decisions.

Planning becomes unnecessarily adversarial.

If Ireland genuinely wishes to be plan-led, our plans must become more detailed and more binding.

One straightforward reform would be the introduction of mandatory zoning envelopes within local area plans. These envelopes would define the maximum building height and bulk for each urban block, much as zoning rules do in New York or Germany.

Ireland has already experimented with this approach in projects such as Adamstown and the Dublin Docklands.

It is sometimes suggested plan-led systems limit democratic participation. In reality, the opposite is true. In genuinely plan-led systems, public debate and political negotiation take place when the plan itself is being prepared. The fundamental decisions are made at the outset, before development begins.

Conflict is therefore front-loaded rather than repeated with every individual planning application.

A system built on clear rules has obvious advantages. It can speed up approval processes, reduce inconsistency and provide a coherent picture of how towns and cities will evolve.

If Ireland truly wishes to be plan-led, the solution is straightforward: our plans must begin to function as plans.

• Garry Miley is a lecturer at South East Technological University’s Department of Architecture