TfL's Bollo Lane Buildings to Meet Passivhaus Standard

Redesign of Phase Three aims to make scheme more sustainable

A visualisation of part of Phase 3 of the Bollo Lane development. Picture: Allies and Morrison

December 18, 2025

Amendments to the design of part of Transport for London’s massive development project, which aim to make it more sustainable, have been submitted to Ealing Council.

Architects Allies and Morrison conducted a Passivhaus feasibility study with consultants, Beyond Carbon, on the third phase of the scheme which revealed the five towers in this part could achieve Passivhaus performance through minor adjustments. A supplementary planning application is now underway to take the scheme forward as Passivhaus.

The development is currently being managed by Bollo Lane LLP, a joint venture between Places for London (TfL’s property company) and Barratt London.

Phase 3 contains a total of 457 flats in five buildings up to 18 storey high, with a commitment to 50% affordable housing (by habitable room). They will be built on top of the brick arches on Bollo Lane along the existing curve of the track for 750 metres.

Construction is expect to begin on this phase in February 2026. The earliest possible date for completion of the first two phases in March 2029 with the third phase likely to be some time after than.

Two taller towers bookend mansion blocks with workspaces and commercial premises occupying the arched colonnade below.

The transition from a standard building design to the Passivhaus standard has necessitated several architectural and mechanical adjustments. These include pivoting to a "fabric-first" design to meet the Passivhaus space heating demand target of 15kWh/m. The documents state that the buildings will generate 86% fewer lifetime emissions compared to standard Building Regulations dwellings. This is estimate to reduce average annual heating and hot water bills in the flats from £800 to £100.

The plan removes the originally consented internal heating substation in Block E and the project will now use individual Exhaust Air Heat Pumps (EAHP) in each home.

The introduction of high-efficiency Mechanical Ventilation with Heat Recovery (MVHR) is another a core component of the new design.

Drawings of the buildings in Phase 3. Picture: Allies and Morrison

To meet the strict thermal requirements of Passivhaus, several "non-material" visual changes are proposed:

There is a reduction in the total glazing area for Blocks C, D, and E to minimize heat loss and new shading canopies are being added to top-level balconies, specifically on the South West elevations, to prevent summertime overheating.

Summary of Key Changes by Block

To accommodate more insulation, the brick "reveals" (the distance the window sits back from the brick face) are being reduced from a full brick to a half-brick reveal.

Block F has been redesigned to include duplex apartments, leading to an increase in height which was not deemed significant enough to warrant .

In addition a former lower-ground-floor cycle store in Block E is being transformed into a commercial unit with new fully glazed arched openings.

There will be a raised platform for the public spaces around the towers. Picture: Allies and Morrison

By moving to individual heat pumps and Passivhaus standards, TfL and Barratt London aim to effectively "future-proofing" the development against rising energy costs and stricter future environmental regulations.