Expand Your Home: Basement Extension! 🏡✨
Milton Keynes, Buckinghamshire, Hertfordshire, Bedfordshire, and Greater London

Expand Your Home: Basement Extension! 🏡✨
Unlock hidden potential by extending downwards with a basement extension, creating vast new living spaces!
Why Build? The Benefits!
- Significant Space Gain: Creates substantial new floor area without impacting garden or above-ground footprint.
- Increased Property Value: Can add considerable value, especially in urban areas where space is at a premium.
- Versatile Use: Ideal for creating large, multi-functional rooms that might not fit elsewhere.
- Privacy & Quiet: Subterranean spaces offer excellent sound insulation and privacy.
- Cheaper Than Moving: A viable alternative to relocating for more space, avoiding high transaction costs.
- Year-Round Comfort: Basements naturally stay cooler in summer and warmer in winter, aiding energy efficiency.
What Can You Create? Ideas for Your New Space!
- Home Cinema/Media Room: The perfect dark, quiet space for entertainment.
- Wine Cellar: A climate-controlled space for connoisseurs.
- Home Gym/Spa: Create your private fitness and relaxation zone.
- Additional Bedroom(s) with En-suite: Ideal for guest suites or older children.
- Large Playroom/Games Room: A dedicated area for family fun.
- Utility Room/Storage: Ample space for practical needs.
- Swimming Pool: For the ultimate luxury basement.
Key Facts & Figures (UK Averages)
💰 Estimated Cost
- £2,700 - £3,500+ VAT per m² (for dig-out and watertight concrete box).
- Total Build Cost: Can range from £200,000 to £575,000+ depending on size, complexity, and fit-out.
- This is one of the most expensive extension types due to excavation and waterproofing.
- Remember to budget for extensive professional fees (architect, structural engineer, party wall surveyor) and a 10-20% contingency!
📈 Value Added
- Under-garden basements can add 30% - 40% to your property value.
- Highly attractive in areas with high property values and limited expansion options.
📏 Average Added Space
- Adds an entirely new floor level below ground.
- The size depends on the plot and planning constraints, but can be substantial.
🗓️ Planning Permission
- Often Required: Basement extensions almost always require full planning permission due to their significant impact.
- Full Planning Application: Typically takes 8-10 weeks for a decision.
- Party Wall Agreements: Crucial and often complex due to excavation near boundaries.
- Overall Project Timeline (Design to Completion): Can be very lengthy, often 1-2 years or more, due to complexity and regulatory requirements.
Ready to dig deep and unlock immense potential? Consult with specialist basement conversion architects and builders to bring your vision to life!
Visualise Your Dream Annex!

External View

Internal View
UK Basement Extension Guide! 🏡✨
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WhatsApp: +44 74040 86195
E-mail: contact@al-haitham.co.uk
Address: Office F7, Gloucester House, 399 Silbury Blvd, Milton Keynes MK9 2AH