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by Sean Hill on May 17, 2023
Through the years, our firm has dived deep (literally!) into many basement projects, harnessing the potential beneath our feet. Here’s what you need to know.
1. The Allure of the Underground: Why Basements?
Many of London’s conservation areas and sensitive locations pose restrictions on above-ground extensions. This leaves homeowners with a basement as the prime alternative for extra space. It’s not a mere excavation but an investment, both financially and emotionally.
View of a basement lightwell in Queen’s Park, North West London
2. How Much Will a Basement Cost?
Starting at around £5,200 per square metre (plus VAT), the initial figures might be intimidating. But, consider this: basement extensions have been known to add a value ranging from £8,500 to an astonishing £23,000 per square metre, especially in upscale areas like West London. For those purely concerned with the financial aspect, this is a promising ROI.
3. The Factors At Play: Why Are Basements Expensive?
Unlike traditional extensions, basements demand more. From excavation to waterproofing, structural interventions to advanced plumbing, the challenges are manifold. Then, there’s the question of lighting. Strategically placed light scoops or double height spaces can work wonders, but they come at a cost.
4. External Components: Going Beyond the Underground
It isn’t just the basement’s interior that demands attention. Externally, one needs to think about light wells, landscaping, rooflights, and more. Furthermore, ventilation becomes crucial, and mechanical solutions might be required to maintain the air quality.
5. Safety First: The Access and Exit Dilemma
In any architectural project, especially basements, safety remains paramount. Apart from the main access, a secondary escape route is essential, ensuring an alternative exit during emergencies.
6. Versatility of Basements: Endless Possibilities
Basements aren’t just storage dungeons. Imagine a serene yoga room or a private cinema lounge. Yes, these can be demanding in terms of cost, but the luxury they offer is unparalleled.
7. Consulting the Experts: Whom to Seek?
Planning a basement isn’t a solo endeavour. Architects, structural engineers, cost consultants, and even party wall surveyors play pivotal roles. As a rule of thumb, consultant fees might oscillate between 11% to 19% of the construction cost, with additional charges for building regulations and party wall agreements.
8. Delving Deeper: The Pre-Planning Phase
Basements are intricate. From geological surveys to assessments of the ground to sun and daylight reports, multiple assessments are crucial. Don’t be startled by the initial investment, as these reports pave the way for a seamless construction journey later.
9. Crafting the Perfect Basement: Aesthetic and Functional Considerations
While the functionality of a basement is important, so is its aesthetic appeal. Using warm, natural materials can transform the space, making it cosy and inviting. Leveraging the basement’s inherent qualities, such as low light, can even be an advantage.
10. The Final Verdict: Is a Basement Worth It?
Constructing a basement is undeniably costlier than above-ground extensions. But, if site restrictions hamper above-ground development, a basement becomes a beacon of hope. It offers the luxury of additional living space without the hassle and expense of relocating.
If you would like to talk through your project with the team, please do get in touch at mail@risedesignstudio.co.uk or give us a call at 020 3947 5886
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