Retrofitting Smart Technology into Older Irish Buildings

The majority of Ireland's commercial building stock was built before 2010. It exists on a spectrum that runs from 1990s suburban office blocks with pneumatic HVAC controls and T8 fluorescent lighting to mid-2000s city centre buildings with basic BMS but no occupancy sensing, no sub-metering and no open protocol integration. The EU Energy Efficiency Directive recast (2023/1791) and the EPBD recast (2024) impose escalating performance obligations on this existing stock — obligations that cannot be met without retrofitting smart building technology into buildings that were never designed for it.

Retrofitting smart building technology into an occupied Irish building is a fundamentally different design challenge from a new-build. Cable runs require disruption to tenants; existing controls infrastructure has unknown condition and undocumented programming; procurement routes must accommodate working in occupied, live buildings with all the health and safety, noise and vibration constraints that entails. This article explains the wireless-first retrofit philosophy that ASDV applies on Irish retrofit projects, the specific protocols and hardware suited to occupied buildings, the retro-commissioning and BMS upgrade pathway, and the SEAI grant mechanisms that can fund up to 50% of eligible retrofit costs.

Wireless Protocol Comparison for Irish Retrofit Projects

Choosing the right wireless protocol is the most consequential technical decision in an Irish smart building retrofit. The options differ significantly in range, power consumption, bandwidth, interoperability and security:

For most Irish occupied commercial retrofit projects, ASDV's recommended approach is a layered wireless strategy: Zigbee 3.0 for dense room-level sensing (occupancy, CO2, temperature, lux), LoRaWAN for campus-level and external monitoring (sub-metering, rooftop weather, car park occupancy), and KNX RF Multi for lighting control where DALI cable replacement would be too disruptive. A single IoT gateway per floor (connected to the building LAN via Cat 6A) aggregates Zigbee and LoRaWAN traffic and forwards to the building IoT platform via MQTT over TLS.

Power over Ethernet Lighting: Retrofit Without Rewiring

Power over Ethernet (PoE) lighting is one of the most significant enablers for Irish smart building lighting retrofits. PoE IEEE 802.3bt (PoE++) delivers up to 90W per port over standard Cat 6A cabling, sufficient to power LED luminaires up to approximately 50W. In a typical Irish open-plan office retrofit, PoE luminaires can replace existing T8 or T5 fluorescent fixtures using the existing data cabling infrastructure — or new Cat 6A cabling installed in the ceiling void without the need for dedicated mains circuits per luminaire.

The retrofit value proposition is: by replacing existing Cat 5e/6 data outlets in the ceiling void with Cat 6A (typically already present or run as part of the retrofit), new PoE luminaires receive both power and DALI-2 control signals over a single cable, managed from a PoE-capable switch in the floor comms room. This eliminates the need for separate 230V lighting circuits to each luminaire location — the most disruptive and expensive aspect of a conventional DALI retrofit. The PoE switch replaces both the distribution board circuit and the DALI power supply for the lighting zone.

Commercially available PoE lighting luminaires from Philips, Silvair and Erco are compatible with IEEE 802.3bt and can integrate with DALI-2 software controllers running on the PoE switch management platform. Irish ELV designers should verify that the existing Cat 6A infrastructure (or the new Cat 6A being installed) is rated for IEEE 802.3bt power delivery — not all Cat 6A installations are — before specifying PoE lighting on a retrofit project.

BMS Retro-Commissioning and Upgrade Pathway

Many Irish commercial buildings from the 2000s have a BMS that was initially programmed for the original tenant configuration, has been partly reconfigured by subsequent occupants, and has never been formally recommissioned. Before investing in new controls hardware, ASDV recommends a structured retro-commissioning process that frequently delivers 15 to 25% energy savings without any new hardware, by identifying and correcting control faults, optimising sequences of operation and eliminating simultaneous heating and cooling in perimeter zones.

Following retro-commissioning, the BMS upgrade pathway to Class B or Class A involves:

1. Protocol gateway installation: Adding BACnet/IP over Modbus TCP gateways to existing DDC controllers that communicate via Modbus or proprietary protocols, exposing their data to a BACnet/IP network accessible to new integration platforms. Cost: €2,000 to €8,000 per floor depending on point count.
2. IoT sensor overlay: Deploying Zigbee or LoRaWAN sensors for CO2, occupancy and room temperature where existing BMS sensor coverage is inadequate. An MQTT-to-BACnet gateway translates sensor data into the BMS point database. Cost: €60 to €150 per sensor node including gateway allocation.
3. Cloud BEMS deployment: Integrating the upgraded BMS via BACnet/IP with a cloud Building Energy Management System (such as EasyIO, Siemens Building X or Schneider EcoStruxure) that provides fault detection and diagnostics, energy benchmarking, tenant-level reporting and demand response capability.
4. DALI-2 lighting controls: Retrofitting DALI-2 lighting controls either via wired DALI bus (if ceiling access is available) or PoE DALI as described above. Integration with the BMS via BACnet/IP gateway provides cross-system occupancy-linked HVAC/lighting optimisation.

SEAI Grant Support for Irish Retrofit Projects

Two SEAI programmes are directly applicable to smart building retrofit in Ireland:

• SEAI Better Energy Communities: Supports commercial building retrofit with grants of up to €3,000,000 per project. Eligible technologies include BMS upgrades, DALI-2 lighting controls with occupancy sensing, LED luminaire upgrades, sub-metering infrastructure, heat pump controls and building envelope insulation. Requires SEAI-registered assessors and project pre-approval.
• SEAI EXEED (Excellence in Energy Efficient Design): Available for major refurbishment projects (where more than 25% of the building envelope surface is being upgraded). EXEED supports 30 to 50% of eligible technology cost on projects exceeding TGD Part L baseline. Smart building controls that contribute to exceeding TGD Part L are eligible costs.

For a typical Irish suburban office retrofit (3,000 m², Class C to Class B upgrade), the eligible CAPEX on controls, sensors and lighting is approximately €120,000 to €200,000. SEAI Better Energy Communities grant support at 40% would provide €48,000 to €80,000, reducing effective CAPEX to €72,000 to €120,000 with a payback from energy savings of 2.5 to 4 years.

Phased Retrofit Approach for Occupied Buildings

For Irish buildings with active tenants, the smart retrofit must be planned in phases that minimise operational disruption. ASDV recommends a three-phase approach:

• Phase 1 — Monitor and Baseline (months 1 to 3): Deploy wireless IoT sensors (Zigbee or LoRaWAN) for CO2, occupancy, temperature and energy sub-metering. Run retro-commissioning on existing BMS. No impact on tenants. Establishes energy baseline data required for SEAI grant applications and quantifies improvement potential.
• Phase 2 — Controls Upgrade (months 4 to 9): Install BACnet/IP gateways to legacy DDC controllers. Upgrade BMS software and sequences. Deploy DALI-2 lighting controls using PoE approach to minimise ceiling disruption. Works scheduled out of business hours for ceiling-accessed items. Tenant impact: minimal; pre-agreed weekend works for switch replacement.
• Phase 3 — Integration and Analytics (months 10 to 12): Commission cloud BEMS platform. Integrate access control for occupancy data. Deploy tenant experience app with environmental dashboard. Commissioning and BREEAM documentation. No tenant disruption.