Space House Fills Slowly After a £110 Million Rebirth

Space House, the Grade II-listed Covent Garden tower, was 45 percent leased or under offer on 1 June 2026. QuadReal had put £110 million into a 1968 speculative office pair and still had to fill it floor by floor.

Harry Hyams left the same cylinder empty for seven years after it opened. The second vacancy is quieter, and it comes with awards.

Harry Hyams Left the Tower Empty for Seven Years

Richard Seifert & Partners, with George Marsh as partner in charge, designed the scheme for Hyams as a bet on London’s 1960s office boom. Robert McAlpine and Sons built it between 1964 and 1968 on the triangle of Kingsway, Kemble Street, Keeley Street and Wild Street, replacing Magnet House with a granite-faced slab and a white concrete drum.

Historic England records that the drum’s round plan was an attempt to protect neighbours’ right to light. Precast cruciform units went up without scaffolding. Huge Y-shaped columns hold the tower. A two-storey bridge ties it to the Kingsway block, and a car park with a filling station filled the basement. The listing file groups it with Centre Point, half a mile west, another Hyams and Marsh job from the same years.

Hyams could wait. Empty offices then carried a light tax load, and capital values were rising even while the lights stayed off. Historic England says Space House sat empty after completion, “allowing Hyams to accrue (untaxed) income on its increasing rental value,” until the Civil Aviation Authority took it in 1975. Remedial work on the columns and radial beams had to finish first. Those were construction faults, the listing says, not a flawed design.

THE EMPTY YEARS

1. 1964-68: Hyams and Seifert & Partners raise a speculative office pair off Kingsway, sold as Space House for its open floors.
2. 1968: The buildings complete and stay without a tenant while rental values climb.
3. 1975: The Civil Aviation Authority moves in after repairs to the columns and beams.
4. 1996 and 2003: Large refits remodel the lobbies and close parts of the original street front.
5. 26 January 2015: Historic England lists the complex at Grade II, entry 1421847.
6. 2018-19: QuadReal, Seaforth Land and Atelier Capital Partners buy the campus; the CAA lease ends.

The CAA held the complex as a single-occupier bunker until 2019. For a generation the drum was a government address, not a marketplace. When the lease ran out, the owners could not knock it down. They also could not treat it as a blank glass plate.

A Grade II Listing Nobody Could Demolish

The Grade II listing from January 2015 calls Space House one of London’s best speculative office buildings, an icon of the 1960s property boom, and a technical marker for a precast grid that could go up fast and still throw a sharp shadow. That protection is why the 2024 job had to be a refit. External insulation was off the table because it would have rewritten the facade Historic England had just frozen.

Seaforth Land founder Tyler Goodwin later said he fell in love with the building when it came up. Goodwin’s firm ran the development with QuadReal. Squire & Partners got the architecture, Atelier Ten the services and the BREEAM file, Pell Frischmann the structure, Donald Insall Associates the heritage brief, and BAM the build. Demolition started in July 2020. Main construction started in April 2022. The campus reopened in October 2024.

The Twentieth Century Society called the result the coolest new office development of 2024, a line the society was happy to repeat on a technical tour. RIBA later gave it a 2026 National Award and the London Conservation Award. The praise is real. So is the remaining void behind the restored fins.

What Squire and Partners Put Back

Tim Gledstone, a partner at Squire & Partners, framed the job as subtraction first. Layers from the 1996 and 2003 refits came off so Marsh’s grid, the radial coffers and the original mosaics in the stairs could show again. Replica cruciform units, matched to the 1960s mix, went in where the roof had to rise.

Originally built in 1968 and refurbished in 1996 and 2003, our design has removed the layers of interventions to retain, expose and celebrate the original architecture and vision.

Tim Gledstone, partner, Squire & Partners

The practice says the work created 255,000 sq ft of workspace, retail and events inside one of the UK’s largest listed buildings to reach BREEAM Outstanding. A new top on the tower adds 12 percent more lettable office, hides air-source heat pumps, and restores a clean silhouette that old condenser stacks had wrecked. The tower now stands 17 storeys, the tallest office in Covent Garden. The block is eight storeys, tied to the drum at the lower floors.

THE RETROFIT MOVES

• The roof: Precast T-pieces came off, were repaired, and went back above new matching cruciform units, with a 3,600 sq ft terrace on the tower.
• The clubhouse: A new top on the block holds a bar and a 5,000 sq ft terrace open to every tenant.
• The basement: A void cut through two floors yields 16,500 sq ft of double-height events space.
• The bikes: One car ramp is now a dedicated cycle entrance; the old garage holds 600 bikes plus showers, lockers and drying rooms.
• The canopy: The filling-station roof at the drum’s base is now the Filling Station restaurant, opening the ground to the street.
• The glass: Each slightly different opening was scanned so new high-performance units, some operable, could sit in the old grid.

Bespoke chilled beams sit in the existing radial coffers. Daylight sensors cut lighting load. The Sky Loft on the 17th floor is a penthouse for a single tenant, with a full London horizon. Common floors use new terrazzo; office floors are loft-style polished concrete. Car culture from 1968 is still in the plan, just pointed at bikes and a public table instead of petrol.

88.6 Percent Without Wrapping the Facade

Younha Rhee, director at Atelier Ten and the BREEAM assessor, said keeping more than 90 percent of the structure saved 10,700 tonnes of carbon against a typical knock-down-and-rebuild. The BRE case study puts upfront embodied carbon at 348 kgCO2 per square metre of gross internal area, and whole-life carbon at 714 kgCO2 per square metre. Squire says the job sits six years ahead of the RIBA 2030 target. The campus is fully electric and billed as net zero carbon.

Remodelling the Brutalist icon has retained more than 90 percent of the existing structure, which has saved 10,700 tonnes of CO2 as embodied carbon.

Younha Rhee, director, Atelier Ten

Outstanding starts at 85 percent. Space House cleared it with a BREEAM Outstanding score of 88.6% under a bespoke Refurbishment and Fit-Out 2014 assessment. The deep fins do the solar shading that a wrap of insulation could not. Roof space and overshadowing limited photovoltaics. Ducts had to live in old risers, so fan power took a hit. Water fittings took the maximum credits, including waterless urinals.

THE GREEN SCORECARD

Those numbers are why the leasing pitch talks about values as much as views. They did not, on their own, fill 17 storeys of a listed drum in a market that still prefers small, ready floors to a grand empty circle.

Blackline, HiBob and the Slow Fill

The first names landed in February 2025. Software firm Blackline took 8,066 sq ft on the seventh floor of the block, sold on the club lounge and the terrace one floor up. A prominent FTSE 250 company took 8,093 sq ft on the sixth floor on a 10-year lease. Seaforth and QuadReal said at the time that 148,000 sq ft of demand was in space planning. That pipeline did not turn into a fully let building.

HiBob, the HR software firm, signed in May 2025 for 19,340 sq ft on two connected floors, also for 10 years. Lou Cooper, office and experience manager at HiBob UK, said the move was about a space that felt welcoming and built for people to thrive, not only about headcount. Spectris joined the early community. Then the original development voice stepped back. QuadReal appointed HB Reavis at the end of 2025 to run leasing and asset management, the first time HB Reavis had managed a building for someone else.

On 1 June 2026 HB Reavis said five further office deals totalled 60,700 sq ft, with 4,460 sq ft under offer, taking the offices to 45 percent leased or under offer. In September the Space House account said office space was almost 50 percent let. BNP Paribas Real Estate put West End vacancy at 6.98 percent in the fourth quarter of 2025, with Grade A vacancy at 1.1 percent. A half-full trophy in that market is not a typical Grade A leftover. It is a 255,000 sq ft listed delivery being eaten in slices.

WHO HAS TAKEN SPACE

John Laing, the infrastructure investor, took a block floor. Claire Silver, its chief people officer, called the building the firm’s new global headquarters and a place to think and collaborate. Wiggin, a media and technology law firm, took a high tower floor. David Quli, managing partner at Wiggin, said the firm wanted an inspiring space with natural light, strong views and a better sustainability story. Sapiens took the 13th floor of the tower as a London HQ, later opening 10,333 sq ft with a customer lab for its software. QuadReal is moving its own UK office into the drum it already owns.

The Keys Pass to HB Reavis

Louise Ioannou, head of workspace and clients at HB Reavis UK, said the new deals show the building will house ambitious companies, and that the job since late 2025 has been to make those benefits clear to more than one kind of tenant. Compton joined CBRE on the office brief. Bruce Gillingham Pollard kept the ground-floor food and shop space, about 24,000 sq ft of retail on the one-acre island. A CAT A+ fit-out in the tower, starting at 4,300 sq ft, is meant to catch firms that will not wait on a full custom floor.

Space House has huge potential for occupiers to mark their home. Since our appointment, we have been working hard to ensure that the benefits of the iconic Space House are clear to diverse businesses.

Louise Ioannou, head of workspace and clients, HB Reavis UK

Jay Kwan, co-president of international equity at QuadReal, said the firm looks forward to sitting in the building beside the new tenants. Hyams wanted one name on the door and held out for it. The 2026 rent roll is the opposite: software, HR tech, law, infrastructure capital, scientific industry, and the landlord itself, stacked in a drum that still has dark floors. That mix is the product. It is also why absorption is slow. Each floor is a separate courtship, not a single government move-in.

The official one-acre workplace campus sells a piazza, a clubhouse with speaker nights, yoga and guest-chef lunches, a concierge, and a cycle park with spa-style showers. Those amenities are built. They work harder when more of the coffered circles above them have names on the door.

A Fashion Show in a Half-Let Tower

On 17 September 2026 the Mithridate show for London Fashion Week used Space House as its venue. Six days later SAVE Britain’s Heritage thanked the building for special access on an Open House walk around Aldwych. Architecture accounts have treated the restored drum as a camera subject since the scaffolding came down. Thirdway has already softened one tenant floor behind the fins, a sign that the people who did sign are spending on the inside.

Hyams proved a listed-looking tower could make money while empty, because the rules of 1968 paid him to wait. The 2015 listing closed that trick and forced the £110 million act of care that won BREEAM Outstanding. The irony is that care produced a trophy large enough, and priced as such, that it still stands half empty in a tight West End. The cylinder is busy as a backdrop. The leases are still arriving one floor at a time.