Space House (One Kemble Street) — Brutalist Adaptive Reuse, London

1968 brutalist office tower in Covent Garden, London; Grade II listed; original HQ of the UK Civil Aviation Authority. Completed a four-year adaptive reuse renovation (2024). Planning reference for 601 Delaware: Grade II listing ≈ NRHP/OHP designation; removing later interventions to reveal original fabric; adding an events venue and hospitality floor without disturbing the listed shell.

Building


Address	Kemble Street, Covent Garden, London
Date	1968
Architects	Richard Seifert & Partners (Richard Seifert + George Marsh)
Listing	Grade II (England’s mid-tier heritage designation; buildings of special interest)
Original use	Civil Aviation Authority headquarters
Scale	260,000 sq ft across two blocks

Form: two elements — a cylinder and a lower box — with an angular modular façade and exposed structural columns. Characteristic of Seifert’s raw, high-density commercial brutalism.

2024 Renovation


Completed	2024 (four-year programme)
Lead architect	Squire & Partners
Cost management / PM	Gardiner & Theobald (also Employer’s Agent, Principal Designer, CDM)
Contractor	BAM
Developers	QuadReal, Seaforth Land, Atelier Capital Partners
Engineering	Atelier Ten (MEP/sustainability); Pell Frischmann (structural)
Sustainability	BREEAM Outstanding; NABERS 4.5; WiredScore Platinum; Net Zero Carbon

Structural addition: two new floors added to the 17-storey tower within the heritage constraints of the Grade II listing.

New program elements

Floor/location	Addition
17th floor	Sky Loft — 360° views; tenant amenity destination
8th floor	Clubhouse — bar + terrace
Basement	Redesigned: storage + events venue
General	Parking; shower facilities

Design approach

“We have removed layers of interventions to retain and celebrate the original architecture” while creating “respectful and highly sustainable new additions.” — Tim Gledstone, Squire & Partners

The renovation stripped decades of fit-out accretions, restoring the original Seifert design intent rather than masking it, then layered in contemporary workplace standards through additions that read as clearly new insertions.

Interior — Vollebak retail activation

A photograph of a Vollebak pop-up inside Space House shows the “remove interventions, celebrate original” principle executed at the room scale. Source: raw-sources/web/2026-05-14-vollebak-spacehouse-retail.md (binary: raw-archives/images/2026-05-14_vollebak-spacehouse-retail.jpg).

The image reads as two deliberately distinct layers:

Preserved original fabric (zero intervention)

Board-formed concrete ceiling — raw, aggregate and pour lines visible; no skim coat
Concrete columns, same finish
Red-painted mechanical pipes left fully exposed along the ceiling plane
Wire cable trays alongside the pipes
Worn concrete floor — original slab, uncoated, full patina retained
Multi-pane industrial windows, metal grid frames; strong natural light

New insertions (clearly contemporary, high contrast)

Blue powder-coated steel pipe clothing racks
Stainless open shelving (garments + publications)
Industrial UFO high-bay pendants; LED strip lights on column faces
Jet engine display prop (Vollebak brand object — their extreme-tech identity)

The key design decision: fixtures are bright, precise, and obviously modern; the building is raw and dominant. Nothing mimics or competes with the concrete. The contents float inside the building rather than covering it.

”Deliberate raw / precise insertion” as a replicable language

Layer	Space House treatment	601 Delaware application
Structural concrete	Zero-intervention, patina preserved	Exposed CMU + concrete frame, 1932 pour lines
Mechanical	Painted accent color (red), fully exposed	HVAC + conduit as ceiling design element
Lighting	High-bay industrial + column LED strips	Track / high-bay; avoid dropped ceiling
Furnishings	Bright-color precision (blue racks)	Coffee bar / museum case metalwork in accent color
Floor	Original slab, uncoated	Original concrete or terrazzo if extant

Relevance to 601 Delaware

Space House	601 Delaware parallel
Grade II listed (heritage designation)	OHP historic designation in progress; NRHP eligibility
Original architecture revealed by removing later interventions	1932 Moderne industrial fabric under Continental-era fit-out
Basement converted to events venue	Basement / loading dock as events / roastery space
Clubhouse with bar on an upper floor	Rooftop terrace / bar concept
BREEAM Outstanding rating	Green rehab as grant-eligibility signal (THC, NPS)
Office → mixed-use (workspace + hospitality)	Industrial → mixed-use (museum + roastery + incubator)
Seifert identity celebrated, not hidden	H&H industrial character as interpretive asset

The Squire & Partners “remove interventions, celebrate original” framing is the exact posture the 601 Delaware reuse takes toward the 1932 factory shell: treat the building’s age and industrial legibility as programming, not as a problem to solve through covering it up.

Open questions

What was the total rehab cost per sq ft? (BREEAM Outstanding + Net Zero at 260,000 sq ft is a data point for budgeting the 601 Delaware scope.) Gardiner & Theobald held cost management; a published case study may include outturn figures.
Does Squire & Partners publish a case study with structural engineering details? Pell Frischmann (structural) and Atelier Ten (MEP/sustainability) may have published separately.
BAM (contractor) and Gardiner & Theobald may have project pages with construction-phase detail not yet ingested.