Office Buildings
An office building lives by its core hours, yet the central plant usually runs to the hours of the last tenant to leave. That is also why the service charge is the most disputed line in the building: energy is shared out without anyone measuring who used it.
Out of hours
The building empties at seven, the plant stops at eleven
Most office buildings have published core hours. The central plant rarely keeps to them. Chillers, air handling units and fan coil pumps run until the last tenant leaves, so one late floor keeps the whole building conditioned.
Weekends follow the same pattern. A single tenant working on Saturday brings the plant on, and the empty floors are cooled along with them. None of this appears as its own line on the bill. It disappears into the monthly total.
- Half-hourly consumption shown against the building’s core hours
- Out-of-hours load split by weekday night and weekend
- Plant, pumps and towers metered separately, with COP on the same screen
Lifts, the car park and facade lighting belong in the same picture. The remote control module puts them on a calendar: the facade follows sunset on an astronomical timer, car park lighting steps down after closing, and exception days are entered in advance.
Weekly Profile
building main meter · 7 daysService charge
Landlord energy shared by measurement, not floor area
In a multi-let building the landlord’s energy is recovered through the service charge, and it is usually apportioned by floor area. That puts an office closing at six and a team working until midnight in the same bracket. The challenge arrives at every year-end reconciliation.
Once floor and tenant supplies are metered, the share stops being an estimate. Common areas, central cooling and lifts are measured as their own lines, and each tenant’s share follows from measured consumption and a defined apportionment key. In new non-domestic buildings over 1,000 m², Part L already requires the sub-metering.
- Floor and tenant supplies separated by sub-meters
- Landlord plant and common areas kept as separate lines
- A monthly statement per tenant, with their own view of their consumption
When a tenant challenges the figure, the answer is not a spreadsheet but a half-hourly record. Which day, which hour and which supply all sit in the same breakdown, so the conversation moves from the number to the rule behind it.
Landlord Energy Share
same month · two keys- By floor area 36 30 20
- By measurement 27 26 28 19 B works late
- Floors 2–4 · Tenant A
- Floor 5 · Tenant B
- Floors 6–7 · Tenant C
- Floor 8 · Tenant D
Extra hours
Out-of-hours HVAC requests, measured
Some tenants ask for heating or cooling outside core hours: an evening board meeting, Saturday working, a quarter-end push. The building manager provides it, but the charge is often a flat rate or nothing at all.
The panel measures and reports those hours. During the requested window, the floor’s own load and the central plant’s consumption are separated, and at month end a per-tenant breakdown of extra hours and extra consumption is produced.
- Requested extra hours entered on the calendar
- Floor load and plant consumption separated for those hours
- Running past the request, or without one, flagged separately
The breakdown is not a billing system. It is a measured report the managing agent uses in their own recharge process. Because it replaces a flat rate with measured hours, it shortens the conversation with the tenant.
Extra Hours Report
month end · by tenant| Tenant | Request | Extra hours h | Extra use kWh |
|---|---|---|---|
| Floors 2–4 · A | none | 0 | 0 |
| Floor 5 · B | weekday evenings | 46 | 6,120 |
| Floors 6–7 · C | Saturdays | 32 | 4,870 |
| Floor 8 · D | none | 18 | 2,240 |
Peaks
Weekday late afternoons cost the most
Most UK office supplies are half-hourly settled, and the distribution charge is split into red, amber and green time bands. Red is the most expensive, and its hours vary by distribution network. In an office building the red band usually lands where the cooling load is still high and the lights are still on.
The second line is agreed supply capacity. The building’s maximum demand is read against the kVA it has agreed with the network, and exceeding it brings excess capacity charges. A hot week can push the peak close to the limit without anyone noticing.
- Half-hourly consumption split into red, amber and green bands
- Maximum demand tracked against agreed capacity in kVA
- A warning before the peak reaches the agreed limit
The same record answers the opposite question at renewal: whether the agreed capacity is higher than the building has ever needed. Bill validation then checks each line of the bill against the measurement record.
Agreed Capacity
maximum demand · this month88%
of agreed kVA
Schematic: maximum demand as a share of agreed capacity. Above the red segment, excess capacity charges apply.
Reporting
When a corporate tenant asks for data
Corporate occupiers now ask landlords for energy and carbon data for their own reporting, whether under SECR or their ESOS Phase 4 assessment. The request often arrives once a year and is answered with a hand-built spreadsheet.
If the tenant supplies are metered, the data already exists. The panel holds each tenant’s direct consumption, their share of common areas and the scope 2 carbon for that electricity, period by period.
- Direct consumption and common-area share kept apart
- Scope 2 carbon calculated with the period’s grid emission factor
- Year-on-year comparison normalised with degree days
The normalisation matters. A cool summer lowers consumption, and reporting that fall as a saving misleads both the tenant and the landlord. What remains after the degree-day correction is the difference that came from how the building was run.
Assistant
from the measurement record-
Tenant C wants their electricity use and carbon figure for the annual report. Is it ready?
- Enver
Yes. The floor 6 and 7 supplies have been metered separately for 12 months; direct consumption is 412 MWh. Their share of common areas and central cooling, using the same key as the service charge, is 138 MWh. Scope 2 carbon for the 550 MWh total is calculated with monthly emission factors, and I can attach the monthly breakdown. One note: the fall against last year looks like 6%, but after degree-day correction it is 2%. Most of the difference came from a cool summer.
- floors 6–7 sub-meters · 12 months
- service charge apportionment key
- period emission factor
- degree days
Which modules work in an office building
| Module | What it does here |
|---|---|
| Energy Consumption | Floor and tenant breakdown, landlord and tenant split, out-of-hours load |
| Chillers and Cooling | Plant COP, pumps and towers, alarms |
| Bill Validation | The building’s bill checked line by line against the measurement record |
| Power Quality | Power factor, harmonics, voltage events |
| Energy Performance and ISO 50001 | Baseline normalised with degree days, CUSUM tracking |
| Remote Control | Schedules and astronomical timer for facade, car park and common areas |
| Standby Power | Generator readiness and UPS load for server rooms |
| AI Assistant | Direct answers on tenant breakdowns, deviations and extra hours |
Server rooms, power quality and the person on call
An office building means hundreds of computers, LED fittings, UPS units and variable speed drives. None of them draw a clean current. Harmonics rise, neutrals run warm and the power factor drifts. On half-hourly sites a power factor below 0.95 also brings a reactive charge, usually small but avoidable. Power quality tracks power factor, harmonics and voltage events on the main board.
Server rooms and their UPS are the fixed part of the night load. Metering them separately shows how much of the out-of-hours consumption is necessary and how much was simply left on. The standby generator behind them is tracked for readiness and test records.
In most office buildings energy lands on one desk, the facilities manager’s or the building manager’s. Alarms are role-based: a plant fault goes to the technical team, a capacity warning to the facilities manager, an overdue generator test to whoever owns maintenance. Alerts go out by email and WhatsApp, and maintenance keeps the plan and what was done side by side.
For related buildings, see commercial buildings, shopping centres and hotels. Guides cover DUoS red band charges, agreed capacity and ESOS Phase 4 data. How a building is scoped is on the pricing page.
Frequently asked
Does every tenant need a meter to split the service charge by measurement?
One measuring point per floor or tenant supply is enough. Common areas, central cooling and lifts are metered separately, and the tenant share follows from measured consumption and a defined apportionment key. Where a floor supply cannot be separated, the floor-area key is kept for that floor.
How do we see the plant running at night and at weekends?
Half-hourly consumption is shown against the building's core hours. With the chillers, pumps and air handling units metered separately, it becomes clear which system and which day the out-of-hours load comes from, and a threshold can be tied to an alarm.
How do we recharge out-of-hours HVAC to a tenant?
The panel measures the requested extra hours, the floor load during them and the central plant consumption, and reports them per tenant. The recharge itself is raised in the managing agent's own system; the panel supplies the measured hours and consumption.
What can we give a corporate tenant who asks for carbon data?
The tenant's direct consumption, their common-area share and the scope 2 carbon for that electricity are exported period by period. Year-on-year comparison is normalised with degree days, so the weather effect is shown separately.
How is an office building priced?
An office building is priced as one site, with the chosen modules added to it. The current list and calculator are on the pricing page.
Let us measure what is happening on your site.
In a one-hour call we look at your existing setup and set out exactly which measurement points are needed and what you would be able to see.