Finnish municipalities operating under an identical national statutory framework exhibit remarkable variation in the duration of detailed planning processes. National statistics indicate that the average duration of detailed plan amendments reached 25.7 months (median 15.6 months) in 2015, compared with just 4.7 months in the case analysed in this article (Rinkinen & Kinnunen, 2017; Ilmajoki municipality records, 2023). This empirical contrast raises a fundamental institutional puzzle: why can similar planning processes under identical legal conditions produce such different outcomes? Rather than attributing the difference solely to political priority or project simplicity, this study investigates whether organisational routines and administrative arrangements within municipalities can systematically influence planning process performance.

The early 2000s were characterised by deregulation and privatisation in Europe, but recent years have brought renewed attention to public regulation in response to environmental imperatives, security concerns, and technological adaptation. Improving efficiency and sustainability in public sector operations remains a widely discussed topic, with recent studies highlighting the impact of governance quality, digitalisation, and human resources on public sector performance (Negri & Dincă, 2023; Capgemini, 2025; Lobonț et al., 2025). Public-sector resources have decreased even as the need for diverse, customer-oriented services has increased. Re-regulation commonly aims to correct market failures, safeguard public interests, and secure equitable access in sectors critical for sustainability and innovation (Moghissi et al., 2014; Meijer & Visscher, 2006; Eliassen & From, 2009; Araral, 2009). In the built environment, these dynamics are reflected in policy agendas related to energy efficiency, climate action, and digitalisation, which have increased expectations for administrative quality, transparency, and procedural streamlining (Radaelli & Meuwese, 2009; Directives 2010/31/EU; 2012/27/EU).

Local and urban planning is a key regulatory instrument shaping conditions for investment, social innovation, and well-being in everyday living environments (Lehtovuori et al., 2019; Ahonen, 2017), while construction-related regulation sets baseline requirements for safety, health, energy performance, and accessibility that interact with planning implementation (Pedro et al., 2011).

Expanded regulatory and procedural expectations are, however, frequently introduced under constrained public-sector resources, creating tension between increasing obligations and declining administrative capacity (e.g. to maintain consistent and transparent processes). Prior research has noted this tension in construction-related governance, where increasing supervisory obligations combined with limited resources can generate delays and administrative burden (Meijer & Visscher, 2006; Jääskeläinen & Virkamäki, 2013).

A practical and research-relevant problem is therefore how municipalities can sustain service quality, legality, and transparency while improving process performance — particularly by reducing plan lead time and avoiding avoidable late-stage iterations. These challenges can be understood as forms of ‘inefficient complexity’: procedural and coordination complexity that absorbs capacity without proportionate gains in substantive outcomes. In land-use governance, such complexity may materialise through multi-actor coordination demands, repeated review cycles, and the accumulation of formal and informal requirements across organisational boundaries (Sulonen & Vastamäki, 2021).

These pressures are visible in Finland, where the 2020s have included active debate on balancing public spending, administrative responsibilities, and the renewal of land-use and building legislation. Legislative reform and digitalisation efforts have aimed at a comprehensive update of the Land Use and Building Act (LUBA 132/1999), with reform work initiated in 2018 and continuing into the 2020s (YM014:00/2018; HE 101/1998; HE 139/2022; BA 751/2023; Ekroos et al. 2018). Regardless of national-level reform trajectories, municipalities must deliver local detailed planning within the existing statutory environment and encounter immediate expectations to digitalise, improve predictability, and maintain due process, openness, and formal legality.

Explaining variation in municipal planning performance requires attention not only to the formal framework, but also to the institutional conditions shaping everyday administrative practice. Institutional theory provides insights for analysing why similar statutory frameworks can yield different performance outcomes across organisations (Scott, 2008). In Scott’s framework, regulatory, normative, and cultural–cognitive pillars interact to stabilise and legitimate organisational behaviour. In local detailed planning, the regulatory pillar comprises statutory requirements and procedural constraints; the normative pillar reflects professional standards, role expectations, and shared notions of appropriate planning conduct; and the cultural–cognitive pillar captures taken-for-granted routines, shared assumptions, and practical ‘scripts’ for how planning work is performed.

Although the article is primarily grounded in institutional theory, the findings also connect to classical debates in planning theory. In particular, the results help clarify how administrative routines influence whether planning processes resemble the structured logic of the rational planning model or the iterative dynamics emphasised in communicative and incremental planning approaches (cf. Stramrud, 2017; Mäntysalo et al., 2023). Recent Nordic research has further highlighted how communicative planning theory evolved through both North American pragmatism and European sociological institutionalism, stressing the interaction between organisational structures and actor agency in planning practice (Westin, 2022).

The institutional perspective adopted here does not replace these traditions but explains how organisational arrangements shape the degree of iteration, coordination, and predictability within planning processes, allowing flexibility on processes to focus on necessary planning purpose. This interpretation aligns particularly well with Nordic and European traditions that emphasise governance capacity, institutional settings, and collaborative problem-solving in public planning.

Moreover, institutional perspectives on public administration are well established, empirical research linking institutional pillars to process-level mechanisms in land-use planning remains comparatively limited (Scott, 2008; Kallio et al., 2016; Peltonen, 2020; Ranta, 2021; Sulonen & Vastamäki, 2021: Bäcklund, 2007). Based on Scandinavian public administration research, a shared legal framework may produce divergent organisational outcomes due to differences in institutional complexity, coordination practices, and administrative autonomy (Kühn, 2021; Rønshaugen et al., 2024). Existing discussions often identify complexity, fragmentation, and change pressures, but provide fewer detailed explanations of how cultural-cognitive elements shape efficiency improvement. This constitutes a theoretical and practical gap: how can municipalities achieve shorter plan lead times within the current national legal framework through administrative arrangements and shifts in shared working practices?

In this article, efficiency is defined primarily as process performance measured through plan lead time and the number of late-stage iterations. Efficiency therefore refers to the reduction of avoidable waiting periods and rework while maintaining statutory participation, legal certainty, and transparency—as distinct from broader effectiveness.

This paper develops a mechanism-based explanation of how municipalities can increase efficiency in local detailed planning by reducing plan lead times within an existing legal framework, thereby translating institutional pillars into actionable process redesign at key governance interfaces. The administrative tools identified—delegation, upstream coordination, and cross-unit leadership—constitute a secondary best-practice account, while the observed cultural–cognitive shifts provide a third, supporting argument about routinisation and sustainability under constrained resources.

This study addresses the gap through a qualitative case study of Ilmajoki municipality, examining local detailed planning as an implemented administrative process. Building on Scott’s institutional pillars, process tracing and thematic analysis are applied to municipal planning documents and process-level evidence to identify how institutional conditions connect to observable mechanisms affecting plan lead time and late-stage iterations.

The study is guided by the following research questions:

How do regulatory, normative, and cultural–cognitive institutional elements shape the organisation and performance of local detailed planning in the Ilmajoki case?

Empirically, the Ilmajoki case indicates that reductions in plan lead time can be achieved without legal reform by: (i) decoupling statutory public display decisions from committee meeting cycles through delegated procedures supported by structured briefings; (ii) shifting inter-organisational coordination upstream to prevent late-stage iterations; and (iii) strengthening cross-unit and cross-organisational leadership and project-based scheduling to reduce internal interface delays. These findings highlight how regulatory requirements operate as boundary conditions, how normative expectations of legality and transparency shape institutional viability, and how cultural–cognitive routinisation stabilises new planning practices.

The remainder of the paper is organised as follows. The next section outlines the institutional framework guiding the analysis. The methods section describes the qualitative case study design, document corpus, and analytical strategy. The results section presents the case chronology and mechanism evidence (Tables 1–2). The discussion elaborates the theoretical and practical contributions, transferability, and boundary conditions, followed by conclusions and directions for future research.

Institutional theory explains how rules, norms, and shared interpretive frameworks become stabilised and taken for granted, shaping organisational behaviour and change over time. Within organisational fields, coercive, normative, and mimetic pressures can lead to convergence in formal structures, while still allowing meaningful variation in how processes are interpreted and enacted in practice (DiMaggio & Powell, 1983; Scott, 2008). This study uses institutional theory to explain how municipalities can increase efficiency in local detailed planning without changing the national legal framework, by focusing on institutional mechanisms embedded in administrative arrangements and routines. It treats organisations as places for social structures and purposes (Powell & DiMaggio, 2012), allowing for changes to be examined at both micro and macro levels (Dacin et al., 2002) e.g. on how institutions can act as significant barriers despite their innovative models (Alasoini 2016).

Following Scott’s three-pillar model, institutional order is sustained through regulatory, normative, and cultural–cognitive elements (Scott, 2008). The regulatory pillar comprises formal rules, oversight, and sanctions. In local detailed planning, it includes statutory procedural requirements, mandated decision points, and legal frameworks that structure the process and set boundaries for permissible streamlining. The normative pillar reflects values and role expectations that define what is considered appropriate public administration. In the planning context, these include commitments to transparency, equality, due process, and professional standards that shape how process choices are justified and contested. Planners interpret legal requirements and public participation obligations through established professional practices, including how coordination with authorities is organised, how planning documents are prepared, and how issues are resolved before formal decision stages. The normative pillar can also function conservatively — professional norms present in public work that valorise thoroughness and caution may resist efficiency-oriented changes even when legally permissible. The cultural–cognitive pillar captures shared understandings and taken for granted routines through which actors make sense of how planning is done. In municipal planning, cultural–cognitive elements include habitual sequencing of tasks, assumptions about risk and acceptability, informal methods for coordination, and shared interpretations of what counts as sufficient preparation before political decision-making (cf. Sulonen & Vastamäki, 2021).

Process performance concepts such as bottlenecks, interfaces, iterations, and rework are central to explaining how institutional arrangements produce structural process delays. A bottleneck arises when a procedural step depends on a constrained resource or schedule (e.g., a committee meeting cycle); an interface delay occurs when coordination between organisational units or actors is hindered; a late stage iteration is a return to a previously completed step due to unresolved issues; and rework refers to substantive plan revisions triggered by late-emerging conflicts. Legality and legitimacy, in this framework, are tied to the public sector’s emphasis on good governance due process and procedural fairness, where streamlining is institutionally viable only if it preserves recognisable compliance and participatory rights (Radaelli & Meuwese, 2009).

Conceptually, the study links institutional conditions to planning performance through a process-mechanism model. Regulatory, normative, and cultural–cognitive elements shape how municipalities design and enact routines, coordination practices, and decision-preparation within the detailed plan process. These routines generate observable process mechanisms—such as early inter-organisational coordination, clarified responsibilities, cross-unit leadership, and anticipatory problem-solving—that influence planning performance. In this context, interface quality, role clarity, and trust are not merely relational goods but process-performance variables: when actors share clear role expectations and resolve interpretive issues early, interface waiting time is reduced and rework is prevented (cf. Houhala, et al. 2021; Sulonen, 2020). This aligns with research on value creation at the interfaces between private and public sectors, which emphasises the importance of coordination quality and information management in collaborative processes. The model therefore treats streamlining as an institutional accomplishment in which efficiency gains must remain compatible with normative expectations of legality and transparency and become stabilised through cultural–cognitive routinisation.

This study employs a qualitative single-case study design to examine how institutional conditions shape the speed and conduct of local detailed planning (the detailed plan process) in Ilmajoki municipality, Finland. The unit of analysis is the municipal detailed plan process for a time-critical planning project, defined as the sequence of formal and informal actions from process initiation to municipal approval. The case was selected as an information-rich and analytically revealing instance: it involved an explicitly accelerated planning objective, concurrent organisational adjustments to planning practice, and conditions that make cultural–cognitive and routine-based mechanisms observable in day-to-day implementation.

The empirical material comprises three categories of documents: (1) internal municipal documents (e.g., project drafts and versions, meeting memos, internal administrative preparations, decisions-in-preparation, and revised administrative rules and role descriptions); (2) public municipal documents (e.g., board and council agendas, minutes, formal approval decisions, and the published plan reports for the case, a school plan amendment, a residential plan extension, and an earlier residential plan, which together provide within-municipality process comparisons); and (3) national legislative and policy documents related to the Land Use and Building Act and its reform trajectory. Documents were collected to cover the full process chronology from initiation to approval and to capture key decision points, role configurations, and coordination arrangements.

The author was the municipal planning director of the unit responsible for detailed planning during the studied process. To mitigate risks associated with an embedded practitioner role, the analysis emphasises institutional mechanisms and organisational routines rather than individual motives. Credibility is strengthened through (a) documentary triangulation between internal and public records, (b) chronological reconstruction of events to reduce retrospective reinterpretation, and (c) explicit consideration of alternative explanations (e.g., project scope and contestation, stakeholder configuration, or legal simplicity) when assessing why plan lead time was reduced.

The embedded practitioner role also affects how cultural–cognitive elements can be observed. Because the study relies primarily on documentary material rather than interviews, shared assumptions and routines are inferred through observable documentary indicators such as recurrent briefing formats, documented scheduling practices, pre-discussion meeting protocols, and the application of delegation as a normalised procedure. These documentary traces are presented in Appendix B.

Analysis proceeded in two integrated steps. First, process tracing was used to reconstruct the causal sequence of actions and decisions and to identify candidate mechanisms linking institutional conditions to planning performance (plan lead time and late-stage iterations). The process was mapped into key phases (initiation, preparation, coordination, public display, decision-making, approval) and examined for temporal ordering and decision dependencies. Second, thematic analysis was applied to the document corpus for the case and additional planning projects for comparison from the municipality, using a hybrid coding approach. Deductive codes were derived from Scott’s institutional pillars (regulatory, normative, cultural–cognitive), operationalised for the planning context. Inductive codes captured locally specific administrative arrangements and routines. Themes were integrated with the process map to identify how pillar-related elements interacted across phases.

To strengthen causal inference, the process-tracing analysis specified in advance the observable implications of three hypothesised mechanisms and three rival explanations. The proposed mechanisms were: (1) delegated display decisions reduce committee-cycle waiting time; (2) upstream coordination reduces late-stage iterations and rework; and (3) project-based cross-unit leadership reduces internal interface delays. These claims were assessed against rival explanations centred on political prioritisation, low contestation or technical simplicity, and a favourable stakeholder configuration. For each explanation, the analysis asked what documentary traces should be visible if that explanation were central to the observed sequence. For example, schedule compression without altered routines would support a priority-based account, whereas repeated evidence of changed decision authority, pre-display issue resolution, and active dependency management would support the institutional-mechanism account.

Evidence was then interpreted using standard process-tracing logic. Hoop-test evidence was used to assess whether each proposed mechanism was at least necessary for the observed sequence; the absence of documentary traces of delegation, pre-discussion coordination, or project-based scheduling would have weakened the mechanism claims decisively. Smoking-gun evidence consisted of documents directly linking an institutional arrangement to reduced waiting time or rework, such as the delegation rule enabling official-level display decisions, pre-discussion records showing issues resolved before formal consultation, and project schedules identifying critical dependencies early. Straw-in-the-wind evidence comprised supportive but non-decisive traces, such as brief non-objecting authority statements, repeated briefing formats, and the absence of late-stage returns for revision. This structure was used to distinguish institutional mechanisms from contextual enabling conditions rather than to treat all favourable circumstances as equivalent causes.

Appendix A presents a three-case comparative process summary. A residential plan approved before 2022, represents planning conducted under the standard previous methods and is consistent with national performance benchmarks from that period (Rinkinen & Kinnunen, 2017). The case plan and an additional residential plan were both processed during the new-methods period (2022– 2024), applying delegated display decisions and upstream coordination. This design allows the analysis to distinguish the effects of institutional arrangements from project-type differences, since the same planning unit produced all three processes under the same statutory framework.

The study aims for analytical generalisation by developing a process-based explanation of how institutional pillars translate into mechanisms affecting planning performance within a stable national legal framework. Limitations include the single-case design and the embedded practitioner role; future research should compare multiple municipalities and planning projects across the Nordic region to assess transferability and boundary conditions.

This section reports findings from the Ilmajoki case study. Planning performance is assessed using plan lead time, defined as the period between initiation and approval of the detailed plan (Rinkinen & Kinnunen, 2017). Nationally, detailed plan amendments have become slower over time: the median duration increased from 9.9 months (2004) to 15.6 months (2015), and the average duration from 14.6 months (2004) to 25.7 months (2015) (Rinkinen & Kinnunen, 2017). The Ilmajoki case, at 4.7 months, thus represents a substantial departure from national norms, and from the municipality’s own performance prior to the introduction of the new administrative arrangements (cf. Appendix A).

The case concerns a detailed plan amendment in the rural village centre of Area B, where already planned residential blocks were amended for school use. The amendment was part of a municipal school programme consolidating multiple schools into a more centralised location and replacing outdated facilities. The municipal council selected the site in spring 2023 and set a time-critical objective for construction, with a target schedule of six months. The amendment was initiated on 17 May 2023 by a municipal board decision and approved on 9 October 2023, resulting in a plan lead time of approximately 4.7 months.

To make the process sequence explicit for the process-tracing analysis, Table 1 reconstructs the key events and decision points from initiation to approval. This chronology provides the temporal backbone for assessing how administrative arrangements and routines translated into reduced waiting time and fewer late-stage iterations.

Process tracing and document analysis indicate that the reduced plan lead time was achieved by reconfiguring administrative arrangements and routines in ways that reduced waiting time and prevented late-stage iterations while maintaining legality and transparency. Table 2 summarises the operational changes and their expected effects.

Table 2 shows that the streamlining affected who made certain preparatory display decisions and when coordination occurred, not whether statutory publicity, consultation, approval, or appeal opportunities applied. In this sense, the accelerated process preserved legality and transparency through unchanged formal notice, display, statement-processing, final approval, and public documentation requirements.

Mechanism 1: Decoupling critical-path procedural steps from political committee meeting cycles (Table 2). In many municipalities, placing draft and proposed plans on statutory public display is tightly coupled to committee and board schedules (often 8–10 meetings per year), affecting the waiting duration of the process. In Ilmajoki municipality, an administrative rule change enabled official-level decisions on statutory public display for both draft and proposed plan stages, while political decision-makers were kept informed through separate, structured briefings. This arrangement reduced plan lead time by removing dependency on the committee meeting cycle while preserving statutory participation rights and maintaining transparency through public documentation. In pillar terms (RQ1), the regulatory pillar functioned as a boundary condition (statutory display requirements remained); the normative pillar shaped the design of the change (maintaining legitimacy through openness and due process); and the cultural–cognitive pillar supported adoption by establishing a new taken-for-granted briefing routine. Mechanistically (RQ2), the key causal pathway was reduced waiting time at formal interfaces: decoupling compressed the critical path by eliminating at least one committee-dependent delay window at each of two display stages.

Mechanism 2: Upstream coordination reducing rework and late-stage iterations (Table 2). Rather than relying primarily on formal authority consultations after public display phases, planning practice emphasised pre-discussions and working meetings with relevant authorities early in the process, with formal consultations initiated only when necessary.–This shifted coordination to an earlier phase, when design choices and interpretations were still more conveniently adjustable. In process terms, early coordination reduces the likelihood that substantive issues (e.g., interpretive disagreements, technical constraints, or laborious preparation of official responses when not needed) surface only after display, which typically triggers additional revision cycles and can reopen previously settled questions. In the case, early working interactions functioned as a preventive mechanism: issues were identified and resolved, generating trust and openness in the discussions.

Based on pillar interaction (RQ1), the normative pillar supports early engagement as a legitimate way to reduce surprises; while the cultural–cognitive pillar is visible in the routinisation of pre-discussion practices and the trust and role clarity they generate. Mechanistically (RQ2), early coordination prevents conflicting interpretations from emerging late, resulting in fewer late-stage iterations and a shorter plan lead time.

Mechanism 3: Project-based planning with strengthened cross-unit leadership and clarified responsibilities (Table 2). The case indicates a shift away from vaguely phased schedules and specialist input toward more continuous cross-unit involvement and critical-path management. Under constrained resources, discontinuities in scheduling often cause re-familiarisation costs. In pillar terms (RQ1) aforementioned shifts reflect a cultural–cognitive change in how planning work is conceptualised from episodic task completion to project-based critical path management supported by normative expectations of accountable and predictable administration. Mechanistically (RQ2), fewer internal bottlenecks and less waiting time at organisational interfaces produce a shorter plan lead time.

Legality and transparency operated as normative requirements shaping which types of streamlining were institutionally viable. The revised process altered the timing and locus of preparatory decisions and coordination, but not the existence of statutory notice, public display, formal statement-processing, final approval, or appeal channels. In practice (RQ3), the adoption of new methods therefore required not only administrative basis and trust as well as recognisable transparency (e.g. procedural continuity, accessible documentation, and political briefings). Similarly, upstream coordination complemented rather than replaced statutory participation. The results support the proposition that accelerated planning outcomes are most likely when the three pillars align and when cultural–cognitive routines with trust stabilise new practices as taken-for-granted ways of working.

Taken together, the Ilmajoki case provides a process-based explanation of accelerated detailed planning (RQ2): reduced plan lead time was achieved by (i) removing schedule dependency at key interfaces (display decisions), (ii) shifting coordination upstream to prevent late-stage iterations, and (iii) strengthening cross-unit leadership and proactive scheduling to reduce internal waiting time. These outcomes were enabled by organisational and managerial practices (RQ3): delegation and briefing routines, early working meetings with authorities, project-based scheduling, and continuous specialist involvement—while remaining compatible with normative expectations of legality and transparency. (see Appendix B) The case thereby illustrates how institutional pillars interact in municipal planning practice (RQ1) and how cultural–cognitive shifts in shared routines can support efficiency under constrained resources without legal reform.

The Ilmajoki case provides a process-based explanation of how municipalities can increase efficiency in local detailed planning under an unchanged national legal framework by reconfiguring administrative arrangements and establishing upstream coordination routines. Across the traced sequence from initiation to approval, the findings suggest that accelerated outcomes were achieved primarily by (i) reducing schedule dependency at critical interfaces, (ii) preventing late-stage iterations through early coordination, and (iii) establishing cross-unit leadership and proactive scheduling. The changes were institutionally conditioned as they remained compatible with legality and transparency and were stabilised as taken-for-granted routines.

Concerning RQ1, the results illustrate how the regulatory pillar operates not merely as a constraint but as a structure around which municipalities organise compliance work. Performance gains emerged through anticipating regulatory requirements and organising work around them upstream. The normative pillar—expectations of due process, transparency, and fair treatment—strongly influenced which streamlining moves were acceptable and how they were justified, including the proactive involvement of stakeholders (e.g. citizens, political decision makers). The cultural–cognitive pillar was visible in the establishment of routines of anticipatory problem-solving and planning project management. In effect, the case supports the view that variation in planning performance under a common legal framework can be explained by differences in how institutional pillars are enacted through routines and coordination practices.

Regarding RQ2, the three mechanisms are each supported by documentary evidence appendix A presents three cases, one of which was processed under the previous methods and is mainly consistent with national performance benchmarks (median 15.6 months: average 25.7 months). The case plan and an additional plan were processed under the new administrative arrangements introduced and analysed in this study, e.g. including delegated display decisions and upstream coordination. The combined evidence from these cases indicate that the full set of upstream coordination practices—particularly pre-display working meetings with all relevant authorities—matters in addition to delegated display decisions alone.

The study’s primary contribution is a mechanism-based explanation linking institutional pillars and process efficiency specifying where and how complexity is reduced while maintaining legitimacy (as public process). As a secondary contribution, the administrative tools identified provide a practically actionable account for Nordic municipalities. The observed cultural–cognitive shifts offer a third, supporting argument: process improvements are more likely to endure when they become established routines rather than imposed rules.

With respect to RQ3, the case indicates that streamlining depended on a specific configuration of organisational and managerial practices. Trust had a key enabling role: when actors shared clear role expectations, early coordination was accepted as a legitimate substitute for formal consultation in many instances.

Appendix A allows the main rival explanations to be assessed as competing rather than merely contextual accounts. Political prioritisation is clearly present in Area B, but it is not sufficient on its own because the explanatory force of the case lies in how time pressure was translated into altered routines and shorter critical-path intervals. Low contestation is likewise part of the explanation, yet it cannot by itself account for the observed compression: few objections reduce friction, but they do not automatically produce delegated display decisions, pre-display problem-solving, or tighter cross-unit scheduling. Technical simplicity also remains only a partial account, since the case still involved groundwater, acid sulphate soil, fuel-storage proximity, and other issues that required anticipatory resolution rather than no resolution. The comparative inference is therefore that political priority, limited contestation, and a favourable stakeholder setting functioned as enabling conditions, whereas the institutional arrangements explain how those favourable conditions were converted into actual procedural time savings.

Regarding transferability, the administrative tools identified—delegation, upstream coordination, and project-based scheduling—target common bottlenecks in detailed planning processes that are present regardless of project type. The analysis suggests that the observed efficiency methods could operate favourably under different project conditions. They are transferable in principle, although the magnitude of lead-time reductions will depend on project complexity and the municipality’s administrative capacity. The claims are analytical rather than statistical: the case identifies mechanisms and enabling conditions that are transferable in principle within the Finnish statutory framework and, by extension, across Nordic systems sharing comparable procedural logics.

Limitations should be acknowledged consistently with the methodological design. The study relies on a single case. The embedded practitioner role provides rich access to internal documents and routines but also introduces potential interpretive bias, despite documentary triangulation. Future research should therefore pursue comparative designs across multiple municipalities and planning projects, ideally combining process tracing with structured cross-case comparison. Such research could test whether the same mechanisms operate under higher contestation, in larger urban municipalities, or under different governance arrangements.

Overall, the study case supports the conclusion that accelerated local detailed planning under an unchanged legal framework is institutionally achievable when municipalities redesign process governance to improve efficiency and use limited resources more sustainably by reducing process duration.

This study examined how institutional conditions shape the speed and conduct of local detailed planning in Finland through a qualitative case study of Ilmajoki municipality. Building on Scott’s three institutional pillars and using process tracing and thematic analysis, the study developed a process-based explanation of how municipalities can reduce plan lead time without changing the national legal framework.

The findings show that acceleration was achieved primarily through administrative and managerial arrangements that reconfigured the planning process considering statutory requirements. Three mechanisms were central: (1) decoupling critical-path procedural steps from political committee meeting cycles through delegated public display decisions supported by structured briefings; (2) shifting inter-organisational coordination upstream to prevent late-stage iterations and rework; and (3) strengthening cross-unit leadership and project-based scheduling to compress internal information exchange and reduce discontinuities under constrained resources. Across these mechanisms, the regulatory pillar acted as a stable boundary condition, the normative pillar shaped legitimacy and acceptability through expectations of legality and transparency, and cultural–cognitive shifts—evidenced in recurring briefing formats, scheduling discipline, and pre-discussion protocols— stabilised new routines as established ways of working. The case thus supports the proposition that accelerated planning outcomes are most likely when the three pillars align, with the cultural-cognitive pillar playing a particularly important and underexplored role in public process reorganisation. The comprehensiveness of upstream coordination is a necessary condition alongside delegated display decisions.

The study contributes to research on planning implementation by operationalising institutional pillars in a municipal process context and linking them to observable performance outcomes through explicit mechanisms. Practically, the results suggest that Nordic municipalities seeking to streamline detailed planning should focus on (i) redesigning governance interfaces that generate avoidable waiting, (ii) treating early inter-organisational coordination as a core performance mechanism, and (iii) investing in cross-unit leadership and critical-path management to reduce rework and internal delays, while maintaining transparency and due process.

Moreover, the cultural–cognitive pillar may also help explain why locally successful process improvements rarely diffuse to the national level: shared interpretive frameworks and informal rules are organisation-specific, and their transfer requires active institutional work and change management. Future research should therefore compare multiple municipalities and planning projects across the Nordic region to test mechanism transferability and identify boundary conditions.

This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors. Both authors are affiliated with Tampere University.