HDR uses digital twin to map EPC B route for 230m Salesforce Tower in the City

Building engineering consultant HDR has completed a data-led services overhaul of 110 Bishopsgate in the City of London for owner Heron International, using a full digital twin to set the 230m tower on a pathway to an EPC B rating.

The work was prompted by what HDR described in CIBSE Journal as unexpectedly high energy consumption during the 2020 pandemic, when occupancy fell but utility bills did not follow.

HDR said its brief covered mechanical, electrical and public health design, together with sustainability, resiliency and lighting. According to HDR's project page, the building already held an EPC C rating before the work began.

Mark Parson, HDR's mechanical project lead, said: "It was about ensuring the building remains competitive in a market where tenants increasingly expect demonstrable environmental performance, operational efficiency and transparency around energy use."

The digital twin

The team started with a RIBA Stage 3 report and survey of critical systems and building management infrastructure, which HDR said established a performance baseline and identified obsolescence in the existing plant. HDR said those early interventions led Heron International to request a full energy remodel of the building.

HDR then deployed a digital twin of the tower fed with 12 months of operational data, which it said allowed the team to pinpoint which floors and systems were underperforming. The model also let the landlord bill tenants on verified consumption data, according to the CIBSE Journal article. HDR describes 110 Bishopsgate as one of the first high-rise towers to adopt digital twin model engineering.

Parson said: "Creating a digital twin allowed us to move beyond assumptions and understand precisely how the building was performing in real operational conditions."

Systems work

The building management system (BMS) upgrade ran in three phases, HDR said. The first replaced obsolete controllers on critical systems and meters that had lost communication with the central platform.

The second phase tackled chiller sequencing after HDR's analysis found the cooling system was wasting significant energy. HDR developed an automated sequencing solution so chillers ran only when needed and at optimal efficiency. The final phase upgraded all remaining BMS controllers and the central head end.

Ventilation gained shut-off dampers and CO2-based occupancy controls, and a specialist provider replaced the public address and voice alarm systems, according to the article. Lighting was swapped for LED fittings with intelligent controls, including occupancy-responsive stairwell lighting, which HDR said delivered about 25-30% electrical energy savings across the building.

HDR said the improvements contributed to BREEAM In-Use Excellent certification and ISO 14001 accreditation. Neither HDR nor CIBSE Journal states the EPC rating recorded after the work.

The building

Heron International says the tower, formerly Heron Tower and now branded Salesforce Tower, was completed in 2011 and has 46 storeys with 36 floors of office space, with bars and restaurants on the ground floor and levels 38 to 40. Heron says floors can be split into units from 5,000 sq ft and that the building carries one of Europe's largest expanses of photovoltaic cells.

The policy picture

The CIBSE Journal article and HDR's project page frame the regulatory driver as a minimum EPC C for commercial lettings by 2025, rising to B by 2030. The government's position has since moved.

In an interim response to its consultation on minimum energy efficiency standards in the non-domestic private rented sector, updated on 18 June 2026, the Department for Energy Security and Net Zero said the previously proposed interim EPC C milestone for 2027 would not be taken forward. It proposed that from 2031 all private rented buildings over 1,000 sq m in England and Wales would need to reach EPC B where cost effective, with buildings below that size staying on the current EPC E minimum.

The department said the seven-year payback test and existing exemptions would remain, and that the EPC B threshold would only take effect after secondary legislation passes through Parliament.

HDR has run a comparable EPC B strategy at 30 Fenchurch Street for Brookfield Properties with TClarke, which it says has taken that building from an E to a B rating, now lodged with the accreditation body.

What happens next

HDR said its sustainability and resiliency team will continue to monitor performance data at 110 Bishopsgate. The digital twin can be used to evaluate future scenarios, including the potential to integrate the building with a district heating network, HDR said.