Open-Plan Living in London Terraces — What's Involved and What It Costs

Understanding what you are working with helps understand the challenge. A typical Victorian terraced house in London was built with:

**Ground floor**: two reception rooms separated by a load-bearing party wall (running front-to-back), and a rear outrigger (the single-storey 'back addition' housing the original kitchen and scullery). The party wall between the front and rear reception rooms is typically load-bearing — it supports the floor structure above and, in some properties, the chimney breast.

**The chimney breast**: most Victorian terraces have two chimney stacks — one at the front (serving the front reception rooms on all floors) and one on the rear party wall (serving the rear rooms). The ground-floor chimney breast projects into the reception room by approximately 700mm–800mm on each side.

**Victorian solid walls**: most pre-1920 London terraces have solid brick external walls (225mm thick — the famous 'nine inch brick'). There is no cavity. Solid walls are cold (high thermal bridging), often damp on the inner face where the pointing has failed externally, and cannot be filled.

**The implication for open-plan**: the front-to-rear wall between the front and rear reception rooms is almost always load-bearing. Removing it or creating a wide structural opening requires: 1. A structural engineer to specify the required RSJ (rolled steel joist) or parallel flange channel beam 2. Temporary propping during works to support the load above while the beam is installed 3. A Building Regulations application — the structural work must be inspected and certified

The most common configuration is a full removal or partial removal of the wall between the front and rear reception rooms, combined with modifications to the rear outrigger (or a rear extension).

**Removing the front-to-rear wall**: 1. Structural engineer's specification commissioned (site visit + 2–3 week turnaround) 2. Temporary propping installed by the structural carpenter 3. Wall demolished in carefully controlled stages 4. Steel beam (RSJ) installed and stitched into masonry on both sides with padstones 5. Propping removed once beam is fully bearing 6. Resulting column (if left at the side for structural reasons) treated as a feature or slim-line steel column 7. New floor and ceiling finished to match 8. Electrics and lighting rerouted

**Chimney breast removal**: where the chimney breast projects significantly into the room and creates an obstruction, it can be removed at ground floor level while leaving the stack above. This requires a separate structural specification for supporting the remaining stack (usually an RSJ at first-floor ceiling level). This is an additional structural cost but significantly improves the floor area.

**Connection through to the rear outrigger**: opening the connection from the main house into the rear outrigger — or extending the outrigger — is the second structural opening. The wall between the main house and the outrigger may also be load-bearing and require its own beam.

**Combined with extension**: in most cases, the maximum impact is achieved by combining the internal wall removal with a rear or side return extension. The combination of opening up the internal layout AND adding floor area at the rear creates the transformative kitchen-dining-living space that defines the London Victorian terrace renovation.

Costs in London (2025):

**Single structural opening (load-bearing wall removal, RSJ beam installed)**: £3,500–£6,500 Includes: structural engineer specification, temporary propping, wall demolition, RSJ installation, making good (plaster, floor, ceiling). Excludes decoration.

**Full open-plan reconfiguration — internal only (no extension)**: £15,000–£35,000 Includes: all structural openings required (typically 2–3 walls and connection to outrigger), new floor screed or boards, plastering, electrics, reconfigured heating. Excludes decoration, flooring finish, kitchen.

**Open-plan reconfiguration with chimney breast removal**: Add £4,000–£9,000 per chimney breast removed (per floor).

**Combined with side return extension**: £50,000–£80,000 total (see: side return extension guide)

**Combined with rear extension**: £55,000–£90,000 total depending on extension size and specification

• **Key variables**:
• •Number of walls being removed or opened up
• •Chimney breast presence and removal decision
• •Span of the structural opening (wider spans require heavier beams)
• •Whether the works are combined with an extension (which provides the opportunity to do all M&E at once)
• •Floor level differences (outrigger floors are often at a different level to the main house)

Creating an open-plan space is not just about removing walls. The design decisions that determine whether the result is exceptional or merely adequate:

**Floor continuity**: running the same floor material continuously from front door to rear garden eliminates the visual division that walls created. Polished concrete, large-format tiles, or engineered timber boards run through all zones. Different floor levels (the outrigger is often 150–200mm lower than the main house ground floor) must be resolved — either by raising the outrigger floor or creating a deliberate step.

**Ceiling height consistency**: where walls are removed, the ceiling heights on each side may differ slightly. The junction must be resolved carefully — either by dropping the higher ceiling to match, or by exposing the structure at the transition in a designed way.

**Natural light**: the front room of a Victorian terrace receives morning light; the rear receives afternoon light. The combined open-plan space can feel dark in the centre. Rooflights positioned over the central zone (often where the old connecting wall was) solve this — and are one of the most powerful design moves in a Victorian terrace.

**Kitchen positioning**: in an extended open-plan space, the kitchen zone is typically at the rear (adjacent to the garden and extension). The cooking position (island vs wall units vs run) determines the feel of the whole space. An island provides a social and functional hub; a run along one wall maximises floor area.

**Structural columns**: where the span is too great for a single beam without intermediate support, a structural column may be required. Steel columns (I-section) exposed as a design feature are a better outcome than masonry piers.