Landlord and communal energy use in a residential block

Landlord energy use residential block figures sit in an awkward gap. The dwelling emissions calculation covers what happens inside each flat and stops at the front door. Lifts, corridor lighting, smoke extract fans, booster pumps, car park ventilation and the standing losses of a communal heating system are none of them inside a dwelling, so none of them appears in the dwelling result. They appear instead in the service charge, in the block's actual metered consumption, and in whatever whole-building reporting the local policy requires.

On a modern block that gap is not small. Communal and landlord supplied energy can be a substantial fraction of what the building draws from the grid, and it is the part residents pay for without choosing it.

What counts as landlord supply

Landlord supply is everything metered to the building rather than to a flat. The list is longer than most design teams assume.

1. Corridor, stair, lobby and external lighting, including emergency lighting on test.
2. Lifts, including standby power for controls, doors and car lighting.
3. Mechanical ventilation and smoke extract, plus any car park ventilation.
4. Water booster pumps, sprinkler or hydrant pumps and their jockey sets.
5. Communal heat generation plant, primary pumps and distribution losses.
6. Door entry, CCTV, gates, aerials and the landlord's electrical panels.
7. Concierge, refuse room, plant room and any shared amenity space.

Two of those dominate. Distribution losses on a communal heating system, and the electrical load of ventilation and pumps running continuously. Lighting used to be the largest item and no longer is, because it responds well to controls.

Loads that sit outside the dwelling calculation

For Building Regulations purposes, the common parts of a block of flats are assessed as a building other than a dwelling, using the non-domestic methodology, while each flat is assessed under the dwelling methodology. Two calculations, two compliance routes, one building.

That split has a practical consequence. The dwelling calculation can show an excellent result while the block as a whole performs poorly, because the losses have migrated to the part nobody is reporting. A heat network with high standing losses makes each flat's regulated figure look good, since the distribution loss falls outside the dwelling boundary.

So an Energy Statement that reports only the dwelling figures is telling half the story. State the communal loads separately, and say which methodology each part was assessed under. Officers reviewing major residential schemes increasingly ask, and where regional policy requires whole-building reporting the question arrives sooner.

Lighting, lifts, pumps and ventilation

Each of the four responds to different design decisions, and the payback varies widely.

Lighting is the straightforward one. Efficient luminaires with presence detection and daylight dimming in corridors and stairs cut consumption sharply, and the constraint is the fire strategy rather than the electrical design: escape routes need maintained illuminance, so the control strategy has to dim rather than switch off. Agree that with the fire engineer at design stage.

Lifts are less obvious. Standby consumption of controls, car lighting and door operators can exceed the energy used for travel in a low-traffic block. Regenerative drives, sleep modes and specifying to the lift energy performance standards matter more than motor efficiency alone.

Pumps reward variable speed control and correct sizing. Oversized booster sets running against a throttled valve are common and wasteful, and the cause is usually a conservative demand assumption made early and never revisited.

Ventilation is the one with the largest scope for reduction, because a naturally ventilated corridor draws nothing. Whether that is available depends entirely on the fire strategy and the building height, so it is a decision made with the fire engineer, not afterwards.

Metering so the cost can be allocated

You cannot manage what is not measured, and residents cannot challenge what is not shown.

Sub-meter the landlord supply by function: lighting, lifts, ventilation, pumps, heat generation. That costs little at construction and it is the difference between a managing agent who can explain a service charge and one who cannot. Where the block has communal heating, the Heat Network (Metering and Billing) Regulations 2014 impose obligations on heat suppliers about metering and billing on the basis of consumption, and the design has to make that possible.

Under the Landlord and Tenant Act 1985 a service charge must be reasonably incurred, and a block where communal energy is a large and unexplained line is where that argument starts. Metering is the applicant's protection as much as the resident's.

Include the metering strategy in the submission. It is a short section and it demonstrates that the communal loads have been thought about rather than left to the contractor.

Design measures that reduce communal demand

In rough order of effect on a typical block:

Reduce heat network distribution losses. Lower flow temperatures, shorter and better insulated risers, minimising the length of pipework in corridors, and attention to the standing losses of heat interface units. The heat networks code of practice is the reference here, and this single item usually outweighs everything else on the list.

Avoid mechanical ventilation of common parts where the fire strategy permits natural ventilation.

Control lighting rather than only specifying efficient fittings.

Specify lifts on their measured energy performance including standby, not on motor rating.

Size pumps for the real demand and control them on variable speed.

And design car park ventilation on carbon monoxide and nitrogen dioxide sensing rather than continuous running.

Illustrative example: a 96 flat block over two cores with a communal air source heat pump plant, where moving the primary risers out of the corridors into dedicated shafts, insulating to a higher specification and reducing flow temperature cut the modelled distribution loss materially, and the corridors stopped needing mechanical cooling. Figures here are illustrative. Where borehole-based systems are being considered, the consent position adds a further step, as our note on ground source heat pumps and borehole permitting explains.

Overheating in the corridors

Distribution losses have a second consequence that gets missed until the first summer. Hot pipework running through a corridor with no ventilation and no cooling produces a space that is uncomfortable in winter and unusable in July.

Overheating assessment methodology includes a separate criterion for communal corridors, precisely because they behave differently from dwellings, and Approved Document O sets requirements for new residential buildings. An Overheating Risk Assessment that assesses only the flats and not the corridors leaves the problem in place, and councils expect a suitably qualified author for that report with professional review strongly advised.

The fix is the same as the energy fix: get the pipework out of the occupied corridor, or insulate it properly and ventilate the space. Mechanical cooling of a corridor is an admission that the riser design failed.

Reporting them in the submission

Three things to include, none of them long.

A schedule of communal and landlord loads with an estimated annual consumption for each, stated as an estimate. The metering strategy. And a short reconciliation showing how the dwelling figures and the communal figures together describe the building, so a reader can see the whole.

Then keep the Sustainability Statement consistent with it. A statement promising low whole-building energy use alongside an energy statement that reports dwelling regulated emissions only is the kind of inconsistency that generates a clarification request.

One honest uncertainty worth acknowledging in the submission: estimated communal consumption at design stage is less reliable than dwelling calculations, because it depends on occupancy patterns, management practice and commissioning quality. Saying so, and offering post-occupancy metering data, is more credible than presenting a precise number nobody can stand behind.

Enter your postcode on PlanScope to see which reports a residential block at your site is likely to need. This is general guidance, not legal advice; check the position with your local planning authority or a qualified professional before relying on it. PlanScope provides AI-assisted draft reports for planning applications. Reports should be reviewed before submission. We do not guarantee planning approval.