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Conference Venue Rooms in London for 400 people

Explore top conference venue rooms in London for 400 people. Perfect spaces for impactful events.

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Trending Conference Venue Rooms Venues in London for 400 People

Finding the perfect conference venue room in London for 400 attendees can elevate your event to new heights.

  • The Marble Arch Hotel by Thistle - image
    From £3,000 per person500

    A vibrant ballroom for up to 300 guests in a central London hotel, ideal for dinners and celebrations.

  • Kia Oval - image
    Vauxhall

    Kia Oval

    From £51 per person400

    A versatile event space with natural light and views of the Oval wicket, ideal for presentations, dinners, and gala events.

  • Hammersmith

    Novotel London West

    From £90 per person1,000

    The fully carpeted and air conditioned Chablis Suite offers a dedicated bar, kitchen, cloakroom and office. Chablis Suite measures 1,360 m 2 (14,638 sq ft) and makes this ground floor space ideal for an exhibition, Events, Trade Fair, Product Launch or Meeting. Your guests get an excellent first impression as they enter the stylish registration area. Inside, the suite offers you the flexibility to let your imagination run wild.

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  • Old Street

    The HAC (Honourable Artillery Company)

    From £7,500 per person690

    The Prince Consort Rooms are an exceptionally sleek and stylish venue that incorporates elements of the HAC's history. Perfect for conferences, annual general meetings, awards ceremonies and more. The vaulted ceilings, hardwood flooring and the abundance of natural light coming from the skylights give the Prince Consort Rooms plenty of character while still remaining a blank canvas for your corporate event.

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  • Marylebone

    The Cumberland Hotel

    From £2,800 per person400

    A uniquely designed event space with a wave-form ceiling, ideal for weddings and meetings in central London.

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  • Wapping

    Studio Spaces

    From £6,500 per person1,000

    A vast 8000sqft industrial-chic venue in East London, ideal for conferences and brand events.

    See venue
  • Chiswick

    Clayton Hotel Chiswick

    From £5,500 per person400

    A versatile, tech-equipped ballroom in West London for up to 330 guests. Ideal for various events.

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  • London

    Hilton London Tower Bridge

    From £89 per person450

    A versatile, bright suite with high ceilings and daylight, ideal for meetings and corporate events.

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Conference Venue Rooms in London for 400 people

Explore top conference venue rooms in London for 400 people. Perfect spaces for impactful events.

About Conference Rooms

### Why London's Conference Venue Landscape for 400 Delegates Has Never Been More Exciting The London conference scene has undergone a remarkable transformation over the past few years, and if you're planning an event for 400 delegates, you're in for a treat. We've witnessed an unprecedented wave of venue innovation that's completely reshaping what's possible for large-scale conferences in the capital. What's particularly exciting is how venues are now purpose-built for the 400-delegate sweet spot. Take the recent developments around King's Cross and Canary Wharf – these aren't just meeting rooms that happen to fit 400 people, they're sophisticated conference ecosystems designed specifically for this scale. We're talking about spaces with 4-6 metre ceiling heights, dedicated 200-amp power supplies, and zoned HVAC systems that can handle the unique challenges of keeping 400 people comfortable whilst maintaining perfect acoustics. The pricing landscape has become refreshingly transparent too. You're looking at day delegate rates ranging from £55-£75 for well-equipped venues in central London, scaling up to £120+ for the premium spaces with cutting-edge hybrid capabilities. What's changed is the value proposition – venues are now bundling in services that used to cost extra, from dedicated event managers to sophisticated streaming infrastructure. #### The Hybrid Revolution Changes Everything Perhaps the most game-changing development is how venues have embraced hybrid events. [London's 8 Best Hybrid Ready Conference Venues](https://hirespace.com/blog/best-hybrid-ready-conference-venues-london/) showcases spaces that can seamlessly blend in-person and virtual attendees – something that was barely possible three years ago. These venues offer minimum 100 Mbps dedicated lines with backup connections, professional streaming setups, and acoustics designed for both live and remote participants. The sustainability angle has also become a genuine differentiator. [The Top Sustainable Conference Venues in London](https://hirespace.com/blog/the-top-sustainable-conference-venues-in-london/) highlights venues achieving ISO20121 certification, which increasingly matters to corporate clients and their stakeholders. What we're seeing is venues competing on experience rather than just space. The best 400-person conference venues now offer everything from dedicated networking areas to flexible breakout configurations that can be reconfigured during breaks. It's this attention to the delegate journey that's making London's conference scene so compelling right now. The key is knowing which venues truly understand the 400-delegate dynamic – and that's where strategic venue selection becomes absolutely crucial. ### The 7 Non-Negotiable Technical Requirements That Make or Break Large Conference Venues After years of watching conferences succeed brilliantly or fail spectacularly, we've identified seven technical requirements that absolutely cannot be compromised when you're dealing with 400 delegates. Miss any of these, and you'll spend your event firefighting rather than facilitating. #### Power Infrastructure That Actually Works Under Load Your venue needs a minimum 200-amp, 3-phase power supply – and here's why that matters. We've seen too many conferences where the AV setup looked perfect during the site visit, only to have projectors dimming and sound cutting out when 400 people's devices start charging simultaneously. The best venues have dedicated circuits for AV equipment, separate from general power outlets. Always ask to see the electrical schematics during your site visit. #### Acoustics Designed for 400 Voices, Not 40 This is where many venues fall short. You need an STC (Sound Transmission Class) rating of at least 50, with proper acoustic treatment including sound-absorbing panels and strategic carpet placement. The ceiling height becomes crucial here – anything under 4 metres will create an echo chamber effect with 400 people. We've found that venues with 5-6 metre ceilings handle large groups far more effectively. #### Internet That Won't Buckle Under Pressure A dedicated 100 Mbps line is your absolute minimum, but honestly, we recommend 200 Mbps for 400 delegates. The key word here is 'dedicated' – shared bandwidth will collapse when everyone's uploading photos and checking emails during breaks. Always insist on a backup connection too. [London's 8 Best Hybrid Ready Conference Venues](https://hirespace.com/blog/best-hybrid-ready-conference-venues-london/) demonstrates how the best spaces handle this challenge. #### Climate Control That Adapts to Human Heat Four hundred people generate approximately 40,000 BTUs of heat – that's like having 10 space heaters running constantly. Your venue needs zoned HVAC with individual section controls, not just one thermostat for the entire space. The system should handle rapid temperature adjustments without creating drafts or noise that interferes with presentations. #### Projection Power That Cuts Through Ambient Light You need projectors with minimum 5,000 lumens – anything less will wash out in a room with 400 people and necessary lighting. Multiple screens are essential too; people beyond 30 metres from a single screen simply can't engage properly. The venues that get these fundamentals right charge £75-£120 per delegate per day, but they're worth every penny when your conference runs flawlessly. ### Mastering London's Conference Venue Geography: Where Location Transforms Your Event Success Location isn't just about prestige when you're managing 400 delegates – it's about logistics, accessibility, and creating the right environment for your specific conference goals. After coordinating dozens of large-scale events across London, we've learned that venue geography can make or break your delegate experience before anyone even steps into the conference room. #### The Transport Triangle That Actually Works The most successful 400-person conferences we've managed cluster around what we call London's "transport triangle" – King's Cross, Liverpool Street, and Canary Wharf. These hubs offer something crucial for large groups: multiple transport options within a 5-minute walk. When you're dealing with 400 people arriving from across the UK and internationally, having access to mainline rail, multiple Tube lines, and reliable bus routes isn't just convenient – it's essential for punctual starts. King's Cross to Canary Wharf takes 25 minutes by Tube, whilst Oxford Circus to Shoreditch is just 15 minutes. These journey times matter when you're coordinating speakers, sponsors, and delegates who might be staying in different areas. We always recommend venues within Zone 1 or 2 for 400-person events – anything further out creates arrival chaos that ripples through your entire schedule. #### The Hidden Costs of Location Choices Here's what many planners miss: central London venues charging £75-£120 per delegate often save money overall. Yes, a venue in Zone 4 might offer £55 rates, but factor in the taxi costs for speakers, the extended lunch breaks needed for delegate travel, and the inevitable late arrivals, and you're actually spending more whilst delivering a poorer experience. Parking becomes critical at this scale too. Central venues typically charge £5-£10 per hour, but they're near public transport. Outer London venues with "free parking" often can't accommodate 100+ cars anyway, forcing delegates onto unfamiliar transport routes. #### Matching Location to Conference Type Corporate conferences work brilliantly in the City or Canary Wharf – your delegates expect that environment. Creative industry events thrive in Shoreditch or Southbank, where the location reinforces your brand message. [Corporate Days Out in London for 100 people](https://hirespace.com/GB/London/Corporate-Days-Out) shows how location choice impacts delegate engagement. The venues that understand 400-person logistics offer dedicated loading bays for equipment, nearby hotels with block booking arrangements, and relationships with local caterers who can handle volume. [The Top 10 Large Conference Venues in London](https://hirespace.com/blog/top-large-conference-venues-in-london/) highlights spaces that've mastered these operational details. Your location choice should align with your delegate profile, transport needs, and post-conference networking plans – because the best conferences extend beyond the venue walls. ### Smart Budget Strategies and Booking Tactics That Save Thousands on 400-Person Conference Venues The difference between paying £22,000 and £48,000 for the same quality 400-person conference often comes down to timing, negotiation strategy, and understanding how venue pricing actually works. After booking hundreds of large-scale events, we've developed tactics that consistently save our clients thousands whilst securing better terms. #### The Tuesday-Thursday Premium That Most Planners Miss Here's something that'll surprise you: venues charge 20-30% more for Tuesday-Thursday conferences, yet these are often the worst days for delegate engagement. We've found that Monday conferences (starting at 10am to allow for travel) or Friday events (ending by 4pm) deliver better attendance rates and cost £8,000-£12,000 less for the same venue. The savings come from lower day delegate rates – dropping from £75 to £55-£60 – plus reduced accommodation costs for overnight delegates. #### The 90-Day Booking Sweet Spot Most venues offer their best rates 90-120 days in advance, but here's the insider trick: they also have last-minute availability discounts at 30 days out. We've secured 40% discounts on premium venues by being flexible with dates. However, for 400-person events, we recommend the 90-day window – it gives you negotiating power without the stress of last-minute logistics. #### Negotiating Beyond the Day Delegate Rate The published DDR is just your starting point. Smart negotiators focus on what's included. Push for complimentary Wi-Fi upgrades (worth £2-£3 per delegate), extended setup time (saving £500-£1,000 in overtime charges), and inclusive AV packages. We've negotiated deals where venues throw in hybrid streaming capabilities – normally £3,000-£5,000 extra – by committing to future bookings. #### The Block Booking Strategy That Transforms Pricing If you're planning multiple events, even across different years, mention this upfront. Venues will often match their lowest competitor's pricing to secure a multi-event contract. We've seen clients save £15,000 annually by bundling their [Company Retreats in Greater London for 200 people](https://hirespace.com/GB/Greater-London/Company-Retreats) with their main conference booking. #### Hidden Costs That Destroy Budgets Watch for these budget killers: security deposits (£2,000-£5,000), overtime charges (£150+ per hour), and equipment delivery fees. Always request an itemised quote showing every potential additional cost. The venues charging £120+ per delegate often include these extras, making them better value than £75 venues with extensive add-ons. Your next step? Create a comparison spreadsheet including all potential extras, not just the headline DDR. The venues that appear most expensive often deliver the best overall value for 400-person conferences. ### Avoiding the 5 Most Expensive Mistakes When Choosing Your London Conference Venue We've watched brilliant conferences turn into expensive disasters because of five recurring mistakes that seem obvious in hindsight but catch even experienced planners off guard. The financial impact of these errors ranges from £5,000 to £25,000 in additional costs – money that could've been invested in better speakers, enhanced delegate experiences, or simply stayed in your budget. #### Mistake #1: Underestimating the True Space Requirements The biggest trap? Booking a venue that technically fits 400 people but creates a miserable experience. We've seen planners book 350m² spaces for 400 delegates because the venue said it was possible – technically true for theatre-style seating, but catastrophic for networking breaks. You need 450-500m² minimum for comfortable movement, registration areas, and essential breakout spaces. The cost of upgrading mid-planning? Often £8,000-£12,000 more than booking correctly from the start. #### Mistake #2: Ignoring the Loading and Setup Reality Here's what venues don't always mention upfront: getting equipment for 400 people into central London venues requires military-level logistics. We've seen conferences pay £3,000+ in emergency courier fees because they didn't account for restricted loading times (typically 6-8am only) or the fact that lifts can't handle large staging equipment. Always visit during a setup day, not just the polished site visit. [6 Exceptional West London Venues for Conferences](https://hirespace.com/blog/exceptional-west-london-venues-for-conferences/) showcases venues that've mastered these operational challenges. #### Mistake #3: The Catering Capacity Blind Spot Four hundred people need feeding, but many venues can only serve 200 simultaneously. This creates 45-minute lunch queues that destroy your afternoon schedule. Worse, some venues charge £15-£25 per person extra for "express service" – costs that weren't in your original quote. Always ask about service capacity and timing, not just menu options. #### Mistake #4: Overlooking the Hybrid Infrastructure Hidden Costs Post-pandemic, most conferences need some hybrid capability, but venues often quote basic streaming at £2,000-£3,000, then hit you with £5,000+ in "technical support" fees for professional-grade delivery. [London's 8 Best Hybrid Ready Conference Venues](https://hirespace.com/blog/best-hybrid-ready-conference-venues-london/) demonstrates venues with transparent hybrid pricing built into their DDR. #### Mistake #5: The Accommodation Coordination Nightmare With 400 delegates, 60-80% will need overnight accommodation. Venues that can't coordinate group bookings at nearby hotels leave you managing dozens of individual reservations. We've seen this administrative burden cost £2,000+ in staff time, plus delegates paying premium rates for last-minute bookings. The smartest move? Create a detailed requirements checklist covering space flow, logistics, catering capacity, technical infrastructure, and accommodation coordination before you start venue hunting. The venues that can tick every box without hidden extras are worth their premium pricing.

Featured Venues for Conference Rooms

Browse 16 venues perfect for Conference Rooms

Dining at The Marble Arch Hotel by Thistle

A vibrant ballroom for up to 300 guests in a central London hotel, ideal for dinners and celebrations.

From: £3000 per person

Capacity: Up to 500 guests

Events at Kia Oval

A versatile event space with natural light and views of the Oval wicket, ideal for presentations, dinners, and gala events.

From: £51 per person

Capacity: Up to 400 guests

Events at Novotel London West

From: £90 per person

Capacity: Up to 1000 guests

Business at The HAC (Honourable Artillery Company)

From: £7500 per person

Capacity: Up to 690 guests

Weddings at The Cumberland Hotel

A uniquely designed event space with a wave-form ceiling, ideal for weddings and meetings in central London.

From: £2800 per person

Capacity: Up to 400 guests

Business at Studio Spaces

A vast 8000sqft industrial-chic venue in East London, ideal for conferences and brand events.

From: £6500 per person

Capacity: Up to 1000 guests

Business at Clayton Hotel Chiswick

A versatile, tech-equipped ballroom in West London for up to 330 guests. Ideal for various events.

From: £5500 per person

Capacity: Up to 400 guests

Business at Hilton London Tower Bridge

A versatile, bright suite with high ceilings and daylight, ideal for meetings and corporate events.

From: £89 per person

Capacity: Up to 450 guests

Events at Leonardo Royal Hotel London Tower Bridge

A spacious, pillar-free event suite with advanced AV tech in a green hotel near Tower Bridge.

From: £49 per person

Capacity: Up to 700 guests

Business at Central Hall Westminster

Versatile, historic venue in Central London with a large adaptable space for up to 1,000 guests.

From: £11500 per person

Capacity: Up to 1000 guests

...and 6 more venues available

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